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Is Australia’s climate confusing you? Here’s why rainfall and temperatures don’t always behave as expected

<div class="theconversation-article-body"><a href="https://theconversation.com/profiles/carly-tozer-1404662">Carly Tozer</a>, <a href="https://theconversation.com/institutions/csiro-1035">CSIRO</a> and <a href="https://theconversation.com/profiles/james-risbey-2011">James Risbey</a>, <a href="https://theconversation.com/institutions/csiro-1035">CSIRO</a> In the past few years in Australia, seasonal rainfall and temperatures have left a lot of people confused. Sometimes, the hot, dry conditions usually associated with an El Niño have not eventuated. Similarly, there have been years where a La Niña did not lead to the cool, wet conditions expected. It’s important for scientists to better understand all weather processes at play, so we can manage expectations around what Australia might experience when climate drivers such as El Niño and La Niña are forecast in future. That’s where our <a href="https://journals.ametsoc.org/view/journals/mwre/aop/MWR-D-23-0112.1/MWR-D-23-0112.1.xml">new research</a> comes in. We examined the state of play in November 2020 and November 2021. La Niña conditions occurred in both years. November 2021 followed the La Niña script and was wet and cool, but November 2020 departed from expectations and was dry and warm. We set out to determine why. We found the differences could be explained by fluctuations in the path of storms over the Australian continent. These fluctuations can be hard to predict well in advance, which makes it difficult to say for certain how a particular La Niña or El Niño event will affect Australia. <h2>A tale of two Novembers</h2> For large parts of Australia, the presence of a La Niña or El Niño <a href="https://theconversation.com/what-to-expect-when-youre-expecting-an-el-nino-the-answer-might-surprise-you-198510">shifts the odds</a> of experiencing wet or dry conditions. Our analysis of Novembers 2020 and 2021 shows how actual outcomes can differ from, or align with, expectations. The first step in our analysis was to examine <a href="https://theconversation.com/what-does-el-nino-do-to-the-weather-in-your-state-218257">other climate drivers</a>, including the Indian Ocean Dipole and Southern Annular Mode. We wanted to know if these drivers were in the same phase – negative, neutral or positive – during those two Novembers a year apart. So what did we find? In addition to La Nina, both Novembers occurred during positive Southern Annular Mode phases and very weak negative Indian Ocean Dipole phases. These phases are typically associated with more rainfall in Australia. So this didn’t explain why November 2020 was hot and dry. Next, we looked to the <a href="http://www.bom.gov.au/climate/about/?bookmark=mjo">Madden Julian Oscillation</a>. When this driver is located in the Australian region, it has been linked to more rainfall in Australia. Although the oscillation was in different phases during November 2020 and 2021, we found in general, this driver does not strongly influence rainfall across all of Australia in November. It was time to look for answers elsewhere. <h2>Jet streams: a key piece in the puzzle</h2> Next, we examined weather systems – in other words, the movement of high and low pressure systems across the globe. These systems are partly controlled by jet streams, which are bands of wind in the upper atmosphere. The effect of jet streams on weather systems, including storms, means they influence rainfall in the regions they pass over. We found there was a strong jet stream over Australia in November 2021. This would have assisted the development of any rain-bearing low-pressure systems moving in from the west, allowing these systems to travel across the Australian continent. These systems brought rain and contributed to the very wet conditions. In November 2020, the jet stream was largely absent over Australia. Instead, it was pushed south of the continent, which means rainfall systems received little help and were also largely steered south. That contributed to the dry month. But why did the jet streams develop in the first place? They form in part due to temperature differences, and are found in the zones where the temperature contrast between warm and cool air is strongest. In November 2021, Australia experienced cooler temperatures over land, but above-average sea surface temperatures in the waters off northern Australia. This pattern set up the zone of strongest temperature contrasts over the continent, which led to a persistent jet stream there. In November 2020, Australia was relatively warm both over land and on the sea surface to the north. This meant that the strongest temperature contrasts (and the jet stream) now sat at the junction between the warm continent and cooler Southern Ocean. <h2>But wait, there’s more</h2> So why were temperatures over Australia so different? To help answer this question we shifted our analysis from the monthly timescale to the daily timescale. That’s because atmospheric features such as jet streams vary strongly from day to day. We found for about the first three weeks of November 2021, a large low-pressure system – also known as a trough – was sitting south of Australia. It pumped cold air onto the continent, cooling it down. This maximised the north-south temperature difference between the warm sea surface temperatures to the north of Australia and the cool of the continent. And as we know, this aided the development of the jet stream over Australia. In November 2020, the continent started off relatively warm. And for a large portion of the month, there was a large high-pressure system over Australia, pulling warmer air from the tropics over the continent. This system would have also promoted clear skies over Australia and enhanced heating coming from the sun, contributing to the warm Australian continent in November 2020. <h2>More puzzle pieces to fit</h2> November 2020’s hot, dry conditions were not the only time a climate driver has failed to bring the conditions some had anticipated. Just last year El Niño <a href="https://www.theguardian.com/australia-news/2024/jan/03/experts-warned-el-nino-was-likely-to-bring-australia-a-hot-dry-summer-what-happened">did not deliver</a> expected dry conditions, leaving many people scratching their heads. Climate drivers play an important role in shaping rainfall. But they’re not the whole story. As our research shows, sometimes they are confounded by changes in weather patterns, which might mean that our expectations of a wet month or season don’t always play out. When it comes to Australia’s climate puzzle, these findings show there’s more to understand about the role of weather.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/233345/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/carly-tozer-1404662">Carly Tozer</a>, Senior Research Scientist, <a href="https://theconversation.com/institutions/csiro-1035">CSIRO</a> and <a href="https://theconversation.com/profiles/james-risbey-2011">James Risbey</a>, Researcher, Oceans and Atmosphere, <a href="https://theconversation.com/institutions/csiro-1035">CSIRO</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/is-australias-climate-confusing-you-heres-why-rainfall-and-temperatures-dont-always-behave-as-expected-233345">original article</a>. </div>

Domestic Travel

Why a cold beer is best – chemically speaking

A quiet moment in a bar has led two researchers to study how alcohol tastes at different temperatures. No, this is real science. <div class="copy"> “Two years ago, Xiaotao Yang and I were drinking beer together. He had just finished his doctorate degree thesis and asked me, ‘what should we do next?’” says Lei Jiang, lead author of a new study <a href="https://doi.org/10.1016/j.matt.2024.03.017" target="_blank" rel="noopener">published</a> in the materials science journal Matter. Yang and Jiang are material scientists at the Chinese Academy of Sciences. “At the time, I was a scientific committee member of one of the biggest Chinese alcoholic beverage companies, and I had the idea to ask the question ‘why does Chinese baijiu have a very particular concentration of alcohol, either 38%–42%, 52%–53%, or 68%–75%?’” Baijiu is a clear grain liquor from East Asia. It’s typically distilled from fermented sorghum (a type of grass), though it is also sometimes made from rice, wheat, barley or millet. “Then we decided, let’s try something, so I put a drop of beer on my hand to see the contact angle,” says Jiang. Contact angle is a measure of surface tension. For example, water has a low contact angle which is why it appears bead-like when placed on a surface. Solutions with high <a href="https://cosmosmagazine.com/health/body-and-mind/debunks-vices-alcohol/">alcohol</a> concentration, however, have a higher contact angle meaning they flatten and spread out. Contact angle also reveals how molecules within the droplet interact with each other and the surface below. After plotting the concentration of ethanol (alcohol) against contact angle, the scientists were surprised with what they found. There is no linear relationship between alcohol concentration and contact angle. Instead, increasing the amount of alcohol leads to a series of plateaus and sharp rises in the plot. Further experiments showed that this arises out of the formation of clusters of ethanol and water in the solutions. At low concentrations, ethanol forms pyramid-like structures around the water molecules. At high concentrations, the ethanol molecules arrange end-to-end in a chain. They also found that these structures change depending on temperature. For example, 38%–42% and 52%–53% ethanol solutions have distinct cluster structures at around room temperature, but this difference disappears at higher temperatures, like 40°C. “Although there is only 1% difference, the taste of baijiu at 51% and 52% is noticeably different; the taste of baijiu at 51% is similar to that of lower alcohol content, such as 38%–42%. So, in order to achieve the same taste at a lower alcohol content, the distribution of baijiu products ranges most within the 38%–42% and 52%–53% categories,” says Jiang. The researchers also found that there is an increase in ethanol chains at 5°C in 5% and 11% ethanol solutions – the concentration range of beer – giving it a more “ethanol-like” taste which is generally preferred. “At low temperature, the tetrahedral (pyramid-shaped) clusters become the low concentration amount, and this is why we drink cold beer,” says Jiang. The researchers say their research could help beverage companies produce the best flavour with the lowest alcohol concentration. Image credits: Shutterstock <div> <noscript data-spai="1"><img decoding="async" fetchpriority="high" class="aligncenter size-full wp-image-198773" src="https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2023/11/Cosmos-Catch-Up-embed_728x150-1.jpg" data-spai-egr="1" alt="Sign up to our weekly newsletter" width="600" height="154" title="why a cold beer is best – chemically speaking 2"></noscript> </div>  <img id="cosmos-post-tracker" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=303282&title=Why+a+cold+beer+is+best+%E2%80%93+chemically+speaking" width="1" height="1" loading="lazy" aria-label="Syndication Tracker" data-spai-target="src" data-spai-orig="" data-spai-exclude="nocdn" /> </div> <div id="contributors"> <a href="https://cosmosmagazine.com/science/chemistry/beer-taste-temperature/">This article</a> was originally published on <a href="https://cosmosmagazine.com">Cosmos Magazine</a> and was written by <a href="https://cosmosmagazine.com/contributor/evrim-yazgin/">Evrim Yazgin</a>. </div>

Food & Wine

6 reasons why global temperatures are spiking right now

<a href="https://theconversation.com/profiles/andrew-king-103126">Andrew King</a>, <a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</a> The world is very warm right now. We’re not only seeing record temperatures, but the records are being broken by record-wide margins. Take the preliminary September global-average temperature anomaly of 1.7°C above pre-industrial levels, for example. It’s an incredible 0.5°C above the previous record. So why is the world so incredibly hot right now? And what does it mean for keeping our Paris Agreement targets? Here are six contributing factors – with climate change the main reason temperatures are so high. <h2>1. El Niño</h2> One reason for the exceptional heat is we are in a <a href="http://www.bom.gov.au/climate/enso/#tabs=Pacific-Ocean">significant El Niño</a> that is still strengthening. During El Niño we see warming of the surface ocean over much of the tropical Pacific. This warming, and the effects of El Niño in other parts of the world, raises global average temperatures by <a href="https://www.realclimate.org/index.php/archives/2023/01/2022-updates-to-the-temperature-records/">about 0.1 to 0.2°C</a>. Taking into account the fact we’ve just come out of a triple La Niña, which cools global average temperatures slightly, and the fact this is the first major El Niño in eight years, it’s not too surprising we’re seeing unusually high temperatures at the moment. Still, El Niño alone isn’t enough to explain the crazily high temperatures the world is experiencing. <h2>2. Falling pollution</h2> Air pollution from human activities cools the planet and has offset some of the warming caused by humanity’s greenhouse gas emissions. There have been efforts to reduce this pollution – since 2020 there has been an <a href="https://sdg.iisd.org/news/imo-advances-measures-to-reduce-emissions-from-international-shipping/">international agreement</a> to reduce sulphur dioxide emissions from the global shipping industry. It has been speculated this cleaner air has contributed to the recent heat, particularly over the record-warm <a href="https://climate.copernicus.eu/record-breaking-north-atlantic-ocean-temperatures-contribute-extreme-marine-heatwaves">north Atlantic</a> and Pacific regions with high shipping traffic. It’s likely this is contributing to the extreme high global temperatures – but only on the order of hundredths of a degree. <a href="https://www.carbonbrief.org/analysis-how-low-sulphur-shipping-rules-are-affecting-global-warming/">Recent analysis</a> suggests the effect of the 2020 shipping agreement is about an extra 0.05°C warming by 2050. <h2>3. Increasing solar activity</h2> While falling pollution levels mean more of the Sun’s energy reaches Earth’s surface, the amount of the energy the Sun emits is itself variable. There are different solar cycles, but an 11-year cycle is the most relevant one to today’s climate. The Sun is becoming <a href="https://edition.cnn.com/2023/07/14/world/solar-maximum-activity-2024-scn/index.html">more active</a> from a minimum in late 2019. This is also contributing a small amount to the spike in global temperatures. Overall, increasing solar activity is contributing only hundredths of a degree at most to the recent global heat. <h2>4. Water vapour from Hunga Tonga eruption</h2> On January 15 2022 the underwater <a href="https://www.jpl.nasa.gov/images/pia26006-hunga-tonga-hunga-haapai-eruption">Hunga Tonga–Hunga Haʻapai volcano erupted</a> in the South Pacific Ocean, sending large amounts of water vapour high up into the upper atmosphere. Water vapour is a greenhouse gas, so increasing its concentration in the atmosphere in this way does intensify the greenhouse effect. Even though the eruption happened almost two years ago, it’s still having a small warming effect on the planet. However, as with the reduced pollution and increasing solar activity, we’re talking about hundredths of a degree. <figure><iframe src="https://www.youtube.com/embed/6oANPi-SWN0?wmode=transparent&start=0" width="440" height="260" frameborder="0" allowfullscreen="allowfullscreen"></iframe></figure> <h2>5. Bad luck</h2> We see variability in global temperatures from one year to the next even without factors like El Niño or major changes in pollution. Part of the reason this September was so extreme was likely due to weather systems being in the right place to heat the land surface. When we have persistent high-pressure systems over land regions, as seen recently over places like <a href="https://www.theguardian.com/environment/2023/oct/01/autumn-heat-continues-in-europe-after-record-breaking-september">western Europe</a> and <a href="https://www.abc.net.au/news/2023-09-19/australia-weather-september-heat-records-tumble/102870294">Australia</a>, we see local temperatures rise and the conditions for unseasonable heat. As water requires more energy to warm and the ocean moves around, we don’t see the same quick response in temperatures over the seas when we have high-pressure systems. The positioning of weather systems warming up many land areas coupled with persistent ocean heat is likely a contributor to the global-average heat too. <h2>6. Climate change</h2> By far the biggest contributor to the overall +1.7°C global temperature anomaly is human-caused climate change. Overall, humanity’s effect on the climate has been a global warming of <a href="https://www.globalwarmingindex.org/">about 1.2°C</a>. The record-high rate of greenhouse gas emissions means we should expect global warming to accelerate too. While humanity’s greenhouse gas emissions explain the trend seen in September temperatures over many decades, they don’t really explain the big difference from last September (when the greenhouse effect was almost as strong as it is today) and September 2023. Much of the difference between this year and last comes back to the switch from La Niña to El Niño, and the right weather systems in the right place at the right time. <h2>The upshot: we need to accelerate climate action</h2> September 2023 shows that with a combination of climate change and other factors aligning we can see alarmingly high temperatures. These anomalies may appear to be above the 1.5°C global warming level referred to in the Paris Agreement, but that’s about keeping <a href="https://climateanalytics.org/briefings/understanding-the-paris-agreements-long-term-temperature-goal/">long-term global warming</a> to low levels and not individual months of heat. But we are seeing the effects of climate change unfolding more and more clearly. The most vulnerable are suffering the biggest impacts as wealthier nations continue to emit the largest proportion of greenhouse gases. Humanity must accelerate the path to net zero to prevent more record-shattering global temperatures and damaging extreme events.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/215140/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/andrew-king-103126">Andrew King</a>, Senior Lecturer in Climate Science, <a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</a> Image credits: Getty Images This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/6-reasons-why-global-temperatures-are-spiking-right-now-215140">original article</a>.

Travel Trouble

Why is it so damn cold right now? A weather researcher explains

<a href="https://theconversation.com/profiles/tess-parker-111039">Tess Parker</a>, <a href="https://theconversation.com/institutions/monash-university-1065">Monash University</a> If you woke up this morning and thought “Gosh, it’s a bit brisk!”, you’re not alone. Temperatures plummeted across southeast Australia this week, with Weatherzone <a href="https://www.weatherzone.com.au/news/coldest-morning-in-5-years-for-parts-of-nsw-qld-act/1342232">reporting</a> Canberra’s low of -7.2ºC was “its lowest temperature since 2018 and the lowest for June since 1986.” Sydney experienced its <a href="https://www.weatherzone.com.au/news/coldest-morning-in-5-years-for-parts-of-nsw-qld-act/1342232">coldest June morning</a> today since 2010, with a temperature of 5.2ºC. In Victoria, temperatures of -7.2ºC were <a href="https://www.weatherzone.com.au/news/coldest-morning-in-5-years-for-parts-of-nsw-qld-act/1342232">recorded</a>. So what’s going on? Here’s what you need to know. <h2>A big pool of Antarctic air</h2> It started off at the beginning of the week, when a low-pressure system saw a big cold front come through southeastern Australia on Sunday night. This basically means a lot of very cold air came from higher latitudes close to Antarctica, and swept across southeastern Australia. So everywhere from Melbourne to Sydney to South Australia was getting this big pool of incredibly cold air at the start of the week. Even though that cold front has now moved off over the Tasman Sea, it has left behind it a really big high-pressure system sitting over the southeast of Australia. This has led to calm conditions, where winds are very light and the skies are clear with not a lot of cloud during the day or night. So it’s getting really, really cold in the early mornings because there are no clouds to act as an insulating blanket for the Earth and trap the heat that the planet radiates to space overnight. The result, in many places, has been very cold temperatures before sunrise, often with a lot of frost. <h2>Remind me, what’s a low-pressure system? And what’s a high-pressure system?</h2> The air above the Earth’s surface has mass, but it’s not uniform everywhere. The way the atmosphere is moved around by what’s going on at upper levels will mean the mass of the atmosphere is redistributed. That transmits down to the surface where we live and causes low- and high-pressure systems. At some points the pressure is lower because there’s not as much mass of air above that point over the Earth. This is what we call a low-pressure system. Air rises in a low, reducing the pressure at the surface. The winds around the low are clockwise in the Southern Hemisphere. So when that low is approaching Australia, the winds on the western side are bringing air from near Antarctica. That’s why a low-pressure system in Australia often means cooler conditions. At some points above the Earth, the pressure is higher because the mass of air above that area is greater. This is what we call a high-pressure system. Air descends in a high, raising the surface pressure. High-pressure systems tend to mean very calm weather; the wind isn’t very strong, the skies tend to be clear and there’s little to no cloud. In summer, that means the sun is baking down all day onto Earth with no protection from cloud. So a high-pressure system in summer can mean a heatwave. In winter, the lack of cloud in a high-pressure system means that much of the heat the Earth has absorbed during the day just re-radiates out to space again, as the cloud isn’t there to act as a blanket and keep all that heat in. That’s why a high-pressure system can mean very cold weather in winter, especially when there are lower levels of sunlight coming in to warm up the Earth in the first place.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/208182/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/tess-parker-111039">Tess Parker</a>, Research Fellow, <a href="https://theconversation.com/institutions/monash-university-1065">Monash University</a> Image credits: Getty Images This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/why-is-it-so-damn-cold-right-now-a-weather-researcher-explains-208182">original article</a>.

Travel Trouble

Big hair? Bald? How much difference your hair really makes to keep you cool or warm

<a href="https://theconversation.com/profiles/theresa-larkin-952095">Theresa Larkin</a>, <a href="https://theconversation.com/institutions/university-of-wollongong-711">University of Wollongong</a> We have <a href="https://theconversation.com/health-check-why-does-womens-hair-thin-out-39126">millions</a> of hair follicles on our body, including around 100,000 on our scalp. This might sound like a lot of hair, yet humans are described as “hairless”. We have evolved to be the only mammals with a relatively hairless body, but still with scalp hair. So how does your hair affect your body temperature when it’s hot or cold? Compared with other animals, our hair does not have as much influence on keeping us warm or cool as you might think. <h2>Essential to our survival</h2> Our brain function and body’s metabolism depend on an optimal temperature of around 37℃. Thermoregulation maintains this body temperature, even when we are exposed to a hotter or colder external temperature. For non-human mammals, body hair or fur plays a role in protecting against environmental cold or heat. For instance, a heavy fur coat helps keep a polar bear <a href="https://polarbearsinternational.org/polar-bears-changing-arctic/polar-bear-facts/adaptions-characteristics/">warm</a> in the cold. But fur also keeps an animal cool in the heat because it can <a href="https://www.jstor.org/stable/25064866">absorb or reflect</a> radiant heat. Scientists think this is why humans have kept hair on our heads. Our heads are exposed to the most heat from the sun, and scalp hair keeps our heads cool. Research published just last week <a href="https://www.pnas.org/doi/10.1073/pnas.2301760120">suggests</a> curly hair provides the best heat protection. That’s because curly hair’s thicker layer of insulation reduces the amount of sun that reaches the scalp. <h2>But hair is not the only factor</h2> When humans moved from living in the jungle to the savannah, they needed to walk and run long distances in the sun. This meant they needed a way to handle the increased body temperature that comes with physical activity in the heat. Sweating is the best way to lose heat and cool down, but the presence of hair reduces sweating and heat loss from the skin. So humans evolved to <a href="https://www.pnas.org/doi/10.1073/pnas.1113915108">lose body hair</a> to be better adapted to exercising in the heat. Fewer hair follicles in our skin made room for more sweat glands. This made our skin optimal for sweat evaporation – and the <a href="https://theconversation.com/want-to-keep-cool-on-hot-summer-days-heres-how-34489">heat loss</a> that goes with it – to keep us cool. <h2>So what’s best in the heat?</h2> You might think removing body hair or having a bald head is best for sweating and keeping cool when exercising in the heat. However, it’s not that simple. Removing head hair would increase the <a href="https://www.pnas.org/doi/10.1073/pnas.2301760120">amount of sun</a> that reaches your scalp. This means you would need to <a href="https://pubmed.ncbi.nlm.nih.gov/20683812/">sweat more</a> during exercise in the sun to reduce an increase in body temperature, but not by much. In fact, it’s the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4667044/#:%7E:text=The%20body%20hair%20is%20advantageous,heat%20removal%20during%20heat%20stress.">least hairy</a> areas of our body that have the highest sweat rates during exercise. These are our forehead, neck, feet and hands. So the best way to keep cool in the heat is to keep these areas uncovered (but still use sunscreen). Removing body hair will not have a large impact on your overall sweat rate. <h2>How about when it’s cold?</h2> Our body hair and head hair theoretically have a role in keeping us warm, but the effects are minimal. When we are cold, the muscles of the hair follicles on the body contract to cause the hairs to stand straight. This is an attempt to trap heat close to the body and we see this as goosebumps. However, because our body hair is so thin, this does not have a big effect in keeping us warm. Our head hair can prevent some heat loss from the head, but again this is limited. When it’s cold, heat can still be lost through the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4667044/#:%7E:text=The%20body%20hair%20is%20advantageous,heat%20removal%20during%20heat%20stress.">skin of the head</a> regardless of your hairstyle. The scalp also has only a very thin layer of fat compared to the rest of our skin, so our head has less insulation to protect against the cold. A warm hat or beanie is the only way to prevent too much heat lost from the head. <h2>In a nutshell</h2> Our head and body hair, or lack of it, does have a small role in how you maintain your body temperature. But overall, your hairstyle does not influence whether you feel warm or cool.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/201380/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/theresa-larkin-952095">Theresa Larkin</a>, Associate professor of Medical Sciences, <a href="https://theconversation.com/institutions/university-of-wollongong-711">University of Wollongong</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/big-hair-bald-how-much-difference-your-hair-really-makes-to-keep-you-cool-or-warm-201380">original article</a>.

Beauty & Style

Stop your makeup melting in the heat

Party season and soaring temperatures mean one thing – melting makeup! Make sure you don’t end up looking like Alice Cooper this summer with our guide to a face that stays put even when the mercury rises. Blank canvas Exfoliate so that your face is ultra-smooth and products will stay on evenly, rather than migrating to one particularly dry area. After your usual moisturizer, make sure you apply SPF30+ or SPF50+ sunscreen. After all, there’s no point in going to all this trouble if you’re just going to end up looking like a tomato anyway! Then use a primer to take away shine. Another layer might seem counter-productive, but you can imagine what happens to make-up that’s applied to a slippery surface. Dare to bare Too much powder and sweat aren’t a good mix, literally. Powders can clog and looked caked when we start to ‘glow’ on scorching days. Similarly, long-lasting foundations can be too heavy and textured and look too much like make-up. Instead, opt for a light coverage foundation or illuminating tinted moisturiser to keep your look sheer and natural. Cheeks Using a brush, apply a cream blush to the apples of your cheeks. The beauty of a cream blush is that if it starts to budge, you can just blend it back in with your finger. Go easy on the bronzer. Use a shade that’s just one shade darker than your natural skin tone and apply it only where the sun would naturally catch your face. Eye Smokey eyes soon become raccoon eyes in the heat, so keep the natural look going with a creamy, slightly shimmery eye shadow in a coppery shade. Stick-style shadows stay in place very well and are easy to reapply on-the-go. Liquid eyeliner is best avoided in the heat. Use a pencil or at least a waterproof formulation. To avoid your eyebrows melting, go for a light pencil rather than a wax, then finish your eyes with waterproof mascara. Lips Thick gloss can feel a bit gloopy when the temperatures soar, and a heavy lipstick will overwhelm the natural look on your eyes and cheeks. Try a light chubby-stick style lip stain or a tinted lip balm with SPF in it to provide sheer colour and sun protection in one. Staying power It’s really important to ‘set’ your face after you’ve applied it, but it’s a fine line between setting it and adding powder that’s just going to cake. Use a good quality translucent powder just on your T-zone. A little goes a long way so dab it on the back of your hand first, then apply from there. Finally, keep some blotting papers in your handbag. Blotting papers don’t just mattify shine- they actually soak up excess oil and sweat, so they’re perfect for hot days! Image credits: Getty Images

Beauty & Style

Warming oceans may force New Zealand’s sperm and blue whales to shift to cooler southern waters

The world’s oceans are absorbing more than <a href="https://www.un.org/en/climatechange/science/climate-issues/ocean-impacts" target="_blank" rel="noopener">90% of the excess heat and energy</a> generated by rising greenhouse gas emissions. But, as the oceans keep warming, rising sea temperatures generate unprecedented cascading effects that include the melting of polar ice, rising seas, marine heatwaves and ocean acidification. This in turn has profound impacts on marine biodiversity and the lives and livelihoods of coastal communities, especially in island nations such as New Zealand. In our latest <a href="https://www.sciencedirect.com/science/article/pii/S1470160X22007075?via%3Dihub" target="_blank" rel="noopener">research</a>, we focused on great whales – sperm and blue whales in particular. They are crucial for maintaining healthy marine ecosystems, but have limited options to respond to climate change: either adapt, die, or move to stay within optimal habitats. We used mathematical models to predict how they are likely to respond to warming seas by the end of the century. Our results show a clear southward shift for both species, mostly driven by rising temperatures at the sea surface. <h2>Computing the fate of whales</h2> Data on the local abundance of both whales species are <a href="https://www.int-res.com/abstracts/meps/v690/p201-217/" target="_blank" rel="noopener">deficient</a>, but modelling provides a powerful tool to predict how their range is likely to shift. We used a <a href="http://macroecointern.dk/pdf-reprints/AraujoNew2007.pdf" target="_blank" rel="noopener">combination of mathematical models</a> (known as correlative species distribution models) to predict the future range shifts of these whale species as a response to three future climate change scenarios of differing severity, as outlined by the Intergovernmental Panel on Climate Change (<a href="https://www.ipcc.ch/" target="_blank" rel="noopener">IPCC</a>). We applied these models, using the whales’ present distributions, to build a set of environmental “rules” that dictate where each species can live. Using climate-dependent data such as sea-surface temperature and chlorophyll A (a measure of phytoplankton growth), as well as static data such as water depth and distance to shore, we applied these rules to forecast future habitat suitability. We chose a scenario of “<a href="https://www.nature.com/articles/d41586-020-00177-3" target="_blank" rel="noopener">modest</a>” response to cutting greenhouse gas emissions (the IPCC’s mitigation strategy RCP4.5), which is the most likely given the current policies, and a worst-case scenario (no policy to cut emissions, RCP8.5), assuming the reality will likely be somewhere between the two. Our projections suggest current habitats in the ocean around the North Island may become unsuitable if sea-surface temperatures continue to rise. These range shifts become even stronger with increasing severity of climate change. For sperm whales, which are currently abundant off Kaikōura where they support eco-tourism businesses, the predicted distribution changes are even more evident than for blue whales, depending on the climate change scenario. While our results do not predict an overall reduction in suitable habitat that would lead to local extinctions, the latitudinal range shifts are nevertheless bound to have important ecological consequences for New Zealand’s marine ecosystems and the people who depend on them. <h2>How whales maintain ecosystems</h2> Great whales are marine ecosystem engineers. They modify their habitats (or create new ones), to suit their needs. In fact, these activities create conditions that other species rely on to survive. They engineer their environment on several fronts. By feeding in one place and releasing their faeces in another, whales convey minerals and other nutrients such as nitrogen and iron from the deep water to the surface, as well as across regions. This process, known as a “<a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0013255" target="_blank" rel="noopener">whale pump</a>”, makes these nutrients available for phytoplankton and other organisms to grow. This is very important because phytoplankton contributes about <a href="https://education.nationalgeographic.org/resource/plankton-revealed" target="_blank" rel="noopener">half of all oxygen to the atmosphere</a> and also captures <a href="https://www.imf.org/Publications/fandd/issues/2019/12/natures-solution-to-climate-change-chami" target="_blank" rel="noopener">about 40% of all released carbon dioxide</a>. By helping the growth of phytoplankton, whales indirectly contribute to the <a href="https://theconversation.com/tiny-plankton-drive-processes-in-the-ocean-that-capture-twice-as-much-carbon-as-scientists-thought-136599" target="_blank" rel="noopener">natural ocean carbon sink</a>. On top of this, each great whale accumulates about <a href="https://www.arcticwwf.org/the-circle/stories/protecting-the-earth-by-protecting-whales/" target="_blank" rel="noopener">33 tonnes of carbon dioxide in their body</a>, which they take to the ocean floor when they die and their carcass sinks. Ultimately, the impact of warming oceans on whale distribution is an additional stress factor on ecosystems already under pressure from wider threats, including acidification, pollution and over-exploitation. <h2>A way forward to help whales</h2> Sperm whales are the largest toothed whales (odontocetes) and deep-diving apex predators. They primarily feed on squid and fish that live near the bottom of the sea. Blue whales are baleen whales (mysticetes) and filter small organisms from the water. They feed at the surface on zooplankton, particularly dense krill schools along coastlines where cold water from the deep ocean rises toward the surface (so-called <a href="https://oceanservice.noaa.gov/facts/upwelling.html" target="_blank" rel="noopener">upwelling areas</a>). These differences in feeding habits lead to divergent responses to ocean warming. Blue whales show a more distinct southerly shift than sperm whales, particularly in the worst-case scenario, likely because they feed at the surface where ocean warming will be more exacerbated than in the deep sea. Both species have important foraging grounds off New Zealand which may be compromised in the future. Sperm whales are currently occurring regularly off Kaikōura, while blue whales forage in the South Taranaki Bight. Despite these ecological differences, our results show that some future suitable areas around the South Island and offshore islands are common to both species. These regions could be considered sanctuaries for both species to retreat to or expand their habitat in a warming world. This should warrant <a href="https://environment.govt.nz/assets/Publications/Files/Environmental-Report-Card-Marine-Areas-with-Legal-protection_0.pdf" target="_blank" rel="noopener">increased protection of these areas</a>. This article originally appeared on <a href="https://theconversation.com/warming-oceans-may-force-new-zealands-sperm-and-blue-whales-to-shift-to-cooler-southern-waters-188522" target="_blank" rel="noopener">The Conversation</a>. Image: Shutterstock

Travel Trouble

As Europe burns, Australia needs to “prepare for 50°C” say experts

The UK’s hottest day on record has given local fire services their busiest day since World War II, wildfires blaze across the Mediterranean and July’s unprecedented European heatwave is yet another example of how climate change will challenge nations. These challenges are expected to roll on in the short-term, with over a month left in what is considered the ‘meteorological summer’. For Australia, experts say the tumbling hot weather records in Europe are a warning to a nation famous for its own sizzling summers. <h2>Records shattered in Europe</h2> The headlines coming out of the region paint a concerning picture. A new record temperature for the UK – exceeding 40°C – has been reached at the same time the nation’s first ever ‘code red’ extreme heat warning was issued. Cities along France’s western coast also saw a mass breaking of temperature records on Monday. In some of these towns, the anomaly – or variation in temperature above the average – has exceeded 16°C. The UK has seen some temperatures clear 20°C above the average. And although some Britons have pointed to their nation’s 1976 heatwave as proof these temperatures are nothing new, meteorologists have swiftly pointed to the widespread nature of these excessive temperatures. <blockquote class="twitter-tweet"> People keep telling me that because the UK had a heatwave in 1976, climate change is overhyped. So here’s the global heat anomaly maps from June 1976 and June 2022. <a href="https://t.co/GGVg46UTcI">https://t.co/GGVg46UTcI</a> <a href="https://t.co/tngiGoEEUl">pic.twitter.com/tngiGoEEUl</a> — Will Norman (@willnorman) <a href="https://twitter.com/willnorman/status/1548547271725240323?ref_src=twsrc%5Etfw">July 17, 2022</a></blockquote> <blockquote class="twitter-tweet"> In 2020, the <a href="https://twitter.com/metoffice?ref_src=twsrc%5Etfw">@metoffice</a> produced a hypothetical weather forecast for 23 July 2050 based on UK climate projections. Today, the forecast for Tuesday is shockingly almost identical for large parts of the country. <a href="https://t.co/U5hQhZwoTi">pic.twitter.com/U5hQhZwoTi</a> — Dr Simon Lee (@SimonLeeWx) <a href="https://twitter.com/SimonLeeWx/status/1547957062000267267?ref_src=twsrc%5Etfw">July 15, 2022</a></blockquote> <blockquote class="twitter-tweet"> We have not seen anything like it. We can't compare this looming heat emergency to summer 1976. A warmer world, thanks to human induced climate change, makes it almost effortless to break extreme heat thresholds. We continue to see this across the planet - not just in Europe. <a href="https://t.co/z0FpZ3Mcbb">pic.twitter.com/z0FpZ3Mcbb</a> — Scott Duncan (@ScottDuncanWX) <a href="https://twitter.com/ScottDuncanWX/status/1548728369738661891?ref_src=twsrc%5Etfw">July 17, 2022</a></blockquote> Eagle-eyed readers will note these present-day anomaly maps show a ‘redder’ globe to those of 46 years ago – the result of far hotter temperatures than average in most parts of the planet. Now that ominous red patch over Europe extends into Northern Africa – home of nations like Morocco and Algeria – which have also battled blazes along their coasts this week. Although wildfires are known events in Mediterranean regions, the severity of fires blazing across Portugal, Spain, France, Italy and Greece is such that tens of thousands of people have been evacuated from homes and holiday areas. These types of events have been predicted for some time, and the Intergovernmental Panel on Climate Change’s 2022 adaptation report emphasised heatwaves and wildfires would continue to impact human health, food security and ecosystem survival. Although heatwaves and vegetation fires are nothing new in parts of Europe and Northern Africa, Dr Rachael Nolan, a researcher in fire ecology from Western Sydney University, says the impact of warming temperatures is creating fire-prone conditions in areas unaccustomed to them. “In many places around the world we are seeing wildfires occurring in places that don’t usually see fire,” says Nolan. “This is driven by climate change pushing up temperatures and drying out fuel. During heatwaves, high temperatures and low humidity causes vegetation to dry out, leaving areas primed for fire. “Fires can then spread quickly when there is an ignition. This is what we are seeing in the UK at the moment. “We are also seeing fires in the Mediterranean Basin, and although fires in this region are not unusual, they are also occurring at the moment due to the heatwave.” <h2>The consequences for human health are many</h2> “As is being witnessed, the UK’s building stock is not designed or built for heat,” says Professor Darryn McEvoy, a research professor in urban resilience and climate adaptation from RMIT. Building materials like concrete are effective at retaining and amplifying heat in built-up areas – a phenomenon known as the urban heat island effect. This can increase the likelihood of heat-related deaths and illnesses, which McEvoy says points to the need to modify towns and cities for the climate of the future. “The heat impacting Europe re-emphasises the need to not only mitigate greenhouse gas emissions as a matter of urgency by reducing our dependence on fossil fuels and moving to ‘net zero’, but also to adapt our urban environments for what, inevitably, will be a hotter future,” McEvoy says. Heat effects aside, urban areas are also more polluted that less densely populated ones. This means atmospheric pollutants, particulate matter that degrades air quality and ozone formation from solar radiation are more likely to occur in periods of extreme heat. It’s why the risk of more severe weather events due to global warming is of concern to health authorities around the world. “When a heatwave goes along with high levels of pollution it exacerbates respiratory, cardiovascular diseases and conditions especially in large urban spaces that are not adapted to cope with these high temperatures,” explains Maria Neira, Director of Environment and Health at the World Health Organisation. “We have been alerting for a long time that climate change is severely affecting human health and therefore taking measures to reach the zero carbon and accelerating the transition to clean renewable sources of energy will be extremely important.” Wildfires like those experienced by parts of Europe and the UK add another complication. With heatwaves capable of exacerbating pollution effects, the release of more toxic substances from widespread vegetation burning increases the risks to human health. Research released on Wednesday by Curtin and Murdoch universities, found a direct link between smoke exposures and attendance at emergency departments. Perth, Western Australia, where these universities are located, has endured several particularly damaging bushfire seasons in recent years. Dr Adeleh Shirangi from Curtin’s School of Population Health led the research that found a 7% increase in emergency admissions. The likelihood of hospitalisations was also higher for those over 60 years of age, from socioeconomic disadvantage and those with pre-existing heart and lung issues. For nations with increasingly ageing populations, this could present healthcare providers with a perfect storm as climate change’s impacts are felt in coming years. “Bushfire smoke consists of a complex mix of particulate matter – PM – and gaseous pollutants such as carbon monoxide and ozone,” explains Shirangi. “And the size of particulate matter that is in bushfire smoke is so small – 2.5 micrometres in diameter – which is about 50 times smaller than the thickness of a strand of human hair. “When we inhale PM2.5, this tiny particulate matter is small enough to penetrate deep into the lungs and the bloodstream. “This can lead us to have various, serious diseases affecting the heart, lungs and brain, and during bushfires, the levels of PM concentration in the air are significantly higher than regulatory air quality standards, so it’s become extremely unsafe.” <h2>Northern hemisphere events are an advance warning for Australia</h2> Just as Australia was stunned by consecutive years of record flooding events more often associated with rainy European winters, so has the northern hemisphere been unprepared for heatwaves that have long been part of the Australian psyche. It’s that Australian ‘preparedness’ for heatwaves and bushfire events that may leave the UK and European nations exposed. Tragic drownings of Britons retreating to lakes and streams for respite, as well as increased hospitalisations from heat stress and smoke inhalation, may become more common headlines in the coming years. While more than three in four Australian households have air conditioning, just 1% of UK homes has a cooling system. Just as Australia looks to the potential impacts of climate change on coastline and floodplain communities, so too will European nations need to consider what adaptations are needed to reduce the burden on an already challenged health system – something Dr Sharon Campbell, from the Menzies Institute for Medical Research at the University of Tasmania, describes as being caught in “a perfect storm of social, cultural and political factors”. An adaptive response is important for already heat-prone nations like Australia. In January 2022, the mercury reached a continental record of 50.7°C in Onslow – a coastal town in Western Australia’s Pilbara region. So although the global focus this week is on temperature records broken in the UK and France, Australia too must consider the impacts of hotter summers on its built-up areas, and high-fuel vegetation. “These factors combine to make this [UK] event a human and environmental disaster,” says Campbell. “The UK has a health system already at breaking point, a government distracted by leadership battles, and an emergency-fatigued population just wanting to have a summer of fun. “Driven by human-induced climate change, extreme and record-breaking temperatures have hit Australia, the United States and now Europe across successive summers. “Australia needs to actively prepare for 50°C in major population centres like Western Sydney. This takes government leadership and community understanding. “We have seen a shift to greater recognition of these risks with a recent change in federal government, and this needs to be urgently followed by greater investment in research, adaptation initiatives and education.” This article originally appeared on <a href="https://cosmosmagazine.com/earth/australia-needs-to-prepare-for-50/" target="_blank" rel="noopener">cosmosmagazine.com</a> and was written by Matthew Agius. Image: Shutterstock

Travel Trouble

Rental properties dip below “safe” temperatures

If you have ever felt freezing cold in your rental apartment, even when you have a blanket wrapped around you and the heater on, you’re not alone. According to a new study, conducted by tenants’ advocacy group Better Renting, rental homes in both New South Wales and Victoria are below the World Health Organisation’s recommended “safe and well-balanced” 18ºC a full 70 per cent of winter months. On top of this, the lowest house temperature recorded so far was a toe-numbingly low 6ºC. While the study is still ongoing, these figures are enough to raise concern. The group’s founder and executive director, Joel Dignam, said that even beyond these 18ºC, there were very low temperatures seen in even relatively warm parts of the two states. “Even in some relatively warmer parts of Australia, the average temperatures are still really low. So in New South Wales and Victoria, the average temperature in the rental properties we’re tracking is still below 18ºC,” he told the ABC. The study involved the group using around-the-clock temperature trackers inside 70 rental homes over seven weeks during winter. On top of these alarming temperatures, Sydney’s wild weather and unrelenting rain since March has meant many homes, specifically rentals, are filled with damp and mould, which thrive in a colder environment. In response to this, landlords have been telling renters it’s not only their responsibility to fix it, but that the solution was to leave windows open for ventilation, bringing in the freezing temperatures. All these elements considered, it seems renters can’t win. While the conclusion of the report has not yet been finalised, hopefully there is some resolution for tenants to be able to live in a warm, and habitable environment. Image credits: Getty Images

Real Estate

Heat yourself, not your house: how to survive winter with a 15℃ indoor temperature

How high should you put the heating up over winter? If you don’t mind the bills and ecological impact, you have the encouragement of the World Health Organization to keep the house warm. They recommend an indoor temperature of <a href="https://apps.who.int/iris/bitstream/handle/10665/275839/WHO-CED-PHE-18.03-eng.pdf" target="_blank" rel="noopener">at least 18°</a>, declaring that you face health risks at lower temperatures. This advice is echoed by the <a href="https://www.energy.gov.au/households/household-guides/seasonal-advice/winter" target="_blank" rel="noopener">Australian government</a>. The tone of <a href="https://www.ncbi.nlm.nih.gov/books/NBK535294" target="_blank" rel="noopener">some reports</a> is monitory and severe. Based on these instructions, anyone would feel a reflex to bump up the thermostat. But before you brace for the bill-shock amid soaring energy prices, consider a different approach. Some people cope positively with the freeze and others face deep winter with panic. Given the range of psychological responses, I can only imagine there would be a difference in how people’s health would fare. If I’m full of dread at the prospect of feeling chilly, this stress could aggravate existing health issues. It is entirely possible to avoid heating your entire house to 18℃ to stay warm. If you view your cold house as a project, you can take pleasure in the power of staying warm in your modern cave, while remembering that we evolved to withstand the cold with fewer options than we have today. Staying warm in a cold house Over the last couple of winters, I’ve discovered many strategies for comfortable living at lower room temperatures. To add to traditional methods such as multiple layers of clothing and physical activity, there are now excellent appliances to fend off the chill. Personal heating devices have become rightly popular, such as electrical heated throw rugs to <a href="https://www.jstor.org/stable/90022948" target="_blank" rel="noopener">warm your clothing</a> rather than ambient air. These new devices – think a more flexible electric blanket – are extremely efficient. Canberra energy efficiency enthusiast David Southgate found using these devices rather than heating the air <a href="https://southgateaviation.files.wordpress.com/2020/02/2019-annual-report-v2.pdf" target="_blank" rel="noopener">cut his heating bill</a> by 95%. <figure class="align-center zoomable"><a href="https://images.theconversation.com/files/472222/original/file-20220704-18-sz6rcn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/472222/original/file-20220704-18-sz6rcn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/472222/original/file-20220704-18-sz6rcn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/472222/original/file-20220704-18-sz6rcn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/472222/original/file-20220704-18-sz6rcn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/472222/original/file-20220704-18-sz6rcn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/472222/original/file-20220704-18-sz6rcn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/472222/original/file-20220704-18-sz6rcn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" alt="electric throw" /></a><figcaption>Electric throw rugs and other personal heating devices are gaining popularity. Shutterstock</figcaption></figure> Personally, I have found adequate clothing makes a temperature of 15℃ acceptable. In fact, dressing warmly poses more risk of overheating with low levels of activity. It’s satisfying to create your own warmth rather than rely on artificially supplied warmth. You start to notice thermodynamic properties of clothing that you’d never appreciate by relying on a thermostat. If you wear a hooded gown, you’ll find not only that your ears are warm from being covered, but your uncovered face becomes flushed. That’s because warmth generated by your body wafts upward to escape through the aperture of the hood. As a result, the air that you breathe is also warm. When it comes to clothing, we can equate warmth simply with insulation. In turn, we assess the insulating qualities of textiles with their thickness or <a href="https://www.abc.net.au/everyday/warmest-materials-fabrics-winter-clothing/101155486" target="_blank" rel="noopener">air-trapping abilities</a>. We often tend to overlook the design of the clothing, which plays a key role in funnelling body warmth to exposed skin. The archetype of the hood was known two millennia before thermostats in both Greece (the garments μαφόρτης and κάλυμμα) and Rome (the garments cucullus, lacerna and tunica palliolata). They’re just as effective today. Wearing a cowl won’t warm up your hands; but if the rest of you is warm – especially your feet – your exposed hands will benefit by the circulation. For anyone unconvinced by this assurance, fingerless gloves are a backstop. The way medical science has catastrophised indoor temperatures lower than 18℃ wouldn’t be so bad if it were only incurious and unimaginative. Alas, there are alarming ecological consequences of a population believing that they’ll automatically get sick in the cold. Carbon emissions from domestic heating are significant. You get a picture from gas bills in Queensland, which go up 1.4 times from summer to winter. In colder states, the figure is <a href="https://www.energycouncil.com.au/analysis/winter-energy-bills-avoid-a-shock" target="_blank" rel="noopener">much higher</a>: 3.5 times in Victoria and 5.2 times in nippy Tasmania. We have to scrutinise if we really need our thermostats pegged at 18℃. Before we accept recommendations on indoor temperatures by medical authorities, we need to know if the science has grappled with different experiences of cold. Future research must distinguish between people in a cool room who feel cold and miserable or feel protected against cold by a range of practical measures. Understanding the effect of these variables is urgent, because current authoritative guidance pushes us into heating our houses more than we have to. For most of the world, that means burning fossil fuel.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/185587/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/robert-nelson-1355694" target="_blank" rel="noopener">Robert Nelson</a>, Honorary Principal Fellow, <a href="https://theconversation.com/institutions/the-university-of-melbourne-722" target="_blank" rel="noopener">The University of Melbourne</a> This article is republished from <a href="https://theconversation.com" target="_blank" rel="noopener">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/heat-yourself-not-your-house-how-to-survive-winter-with-a-15-indoor-temperature-185587" target="_blank" rel="noopener">original article</a>. Image: Getty Images

Home Hints & Tips

Young girl fights for life after being left on bus in roasting temperatures

A three-year-old has been left fighting for her life after she was found unresponsive from being on a daycare bus outside a Queensland childcare centre for nearly six hours. Temperatures in Rockhampton reached 28 C on Wednesday, and it’s believed that three-year-old Nevaeh Austib had been on the bus - parked outside the Le Smileys Early Learning Centre near Rockhampton - since she was picked up from her family’s home at 9am. She was found unconscious at approximately 3pm and rushed to Rockhampton hospital in critical condition. Nevaeh’s father, Shane Austin, told the <a href="https://www.couriermail.com.au/news/queensland/rockhampton/child-found-in-critical-condition-on-bus-at-le-smileys-early-learning-centre-on-lucas-street-in-gracemere/news-story/c86e5ffa4a41f1c4d6ef8631fe547f25" target="_blank" rel="noopener">Courier Mail</a> his little girl has since been taken to a Brisbane hospital to undergo a deep brain scan and treatment for potential kidney failure. “She’s the most loudest little girl they tell me … she’s the heart of the daycare,” he said. The childcare centre has remained closed as of Thursday morning. Jason Thompson, the operations manager for Queensland Ambulance’s Central Region service, told media on Wednesday that Nevaeh was found “unresponsive” and described the situation as “traumatic” for those who treated her, per <a href="https://www.dailymail.co.uk/news/article-10783585/Karl-Stefanovic-breaks-girl-fights-life-left-daycare-bus-Rockhampton.html" target="_blank" rel="noopener">The Daily Mail</a>. “On the crew’s arrival Queensland Police were already on scene and escorted the crew into the childcare centre where the young child was on the floor in the admin room,” he said. Police have launched an investigation into the incident and interviewed the daycare staff, according to <a href="https://www.9news.com.au/national/child-critical-after-being-left-on-central-queensland-bus-rockhampton/7cb7646c-350e-4cf5-908e-0d0f7d69f58d" target="_blank" rel="noopener">9News</a>. It comes just two years after Muriel Namok’s three-year-old son died after being left on a minibus by childcare staff for a similar amount of time in Cairns. Ms Namok appeared on the Today Show on Thursday morning and shared her anger at Nevaeh’s situation, saying it made her “sick to her stomach”. “It’s just too tragic. Again, why?” she told co-hosts Ally Langdon and Karl Stefanovic. “This is terrible. “I feel really sick to my stomach. Angry. I know this feeling too well.” <img src="https://oversixtydev.blob.core.windows.net/media/2022/05/karl-nevaeh.jpg" alt="" width="1280" height="720" /> Today show hosts Karl Stefanovic and Ally Langdon fought back tears after speaking to the mum who lost her son in a similar situation. Image: Nine She said that parents should be able to trust that their children are safe in childcare centres, and that the centres need to take responsibility when things go wrong. “They are taking our children and we are trusting them to bring them back,” Ms Namok said. “For this to happen, they need to be held accountable.” After speaking to the grieving mum, who broke down as the interview ended, both Stefanovic and Langdon were fighting back tears live on air. “It’s horrendous,” Stefanovic said. “There’s nothing else to say to that,” Langdon added. “And that poor family. It really shouldn’t happen.” Image: Nine

News

This WA town just topped 50℃ – a dangerous temperature many Australians will have to get used to

While Australians are used to summer heat, most of us only have to endure the occasional day over 40℃. Yesterday though, the temperature <a href="https://www.abc.net.au/news/2022-01-13/onslow-in-the-pilbara-equals-australias-hottest-day-on-record/100754082">peaked at 50.7℃</a> in Onslow, a small Western Australian town around 100km from Exmouth. Remarkably, the town sits right next to the ocean, which usually provides cooling. By contrast, the infamously hot WA town of Marble Bar has <a href="https://www.abc.net.au/news/2022-01-01/marble-bar-christmas-hottest-town-australia/100731946">only reached 49.6℃</a> this summer, despite its inland location. If confirmed, the Onslow temperature would equal Australia’s hottest on record <a href="https://www.news.com.au/technology/environment/climate-change/oodnadatta-holds-the-record-for-australias-hottest-temperature-and-it-looks-set-to-get-even-warmer/news-story/36a0585310acc37be3d14674569526a3">set in Oodnadatta</a>, South Australia, in January 1960. It would also mark only the fourth day over 50℃ for an Australian location since reliable observations began. Unfortunately, this extreme heat is becoming more common as the world heats up. The number of days over 50℃ has <a href="https://www.bbc.com/news/science-environment-58494641">doubled since the 1980s</a>. These dangerous temperatures are now being <a href="https://www.theguardian.com/cities/2018/aug/13/halfway-boiling-city-50c">recorded more often</a> – not just in Australia but in cities in Pakistan, India and the Persian Gulf. This poses real threats to the health of people enduring them. <h2>Where did the heat come from?</h2> Hitting such extreme temperatures requires heat to build up over several days. Onslow’s temperatures had been <a href="http://www.bom.gov.au/jsp/ncc/cdio/weatherData/av?p_nccObsCode=122&p_display_type=dailyDataFile&p_stn_num=005017&p_startYear=">close to average</a> since a couple of heatwaves struck the Pilbara in the second half of December. So where did this unusual heat come from? <a href="https://images.theconversation.com/files/440801/original/file-20220113-19-77sy3.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/440801/original/file-20220113-19-77sy3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="" /></a> This weather chart from 13th January 2022 illustrates the conditions just half an hour before the record-equalling 50.7℃ was recorded. The blue dashed line marks the trough which meets the coast close to Onslow and helped bring in the hot air. Bureau of Meteorology In short, from the bakingly hot desert. South to south-easterly winds blew very hot air from the interior of the state up to Onslow. The wind came from an area that has had little to no rainfall since November, so the very hot air was also extremely dry. Dry air kept the sun beating at full intensity by preventing any cloud cover or storm formation. The result? The temperature rose and rose through the morning and early afternoon, and the temperature spiked at over 50℃ just before 2.30pm local time. <h2>Aren’t we in a cooler La Niña period?</h2> Australia’s weather is strongly linked to conditions in the Pacific Ocean. At the moment we’re in <a href="http://www.bom.gov.au/climate/enso/">a La Niña event</a> where we have cooler than normal ocean temperatures near the equator in the central and east Pacific. La Niña is typically associated with cooler, wetter conditions. But its effects on Australian weather are <a href="http://www.bom.gov.au/climate/about/?bookmark=lanina">strongest in spring</a>, when we had unusually <a href="https://theconversation.com/back-so-soon-la-nina-heres-why-were-copping-two-soggy-summers-in-a-row-173684">wet and cool conditions</a> over the east of the continent. During summer the relationship between La Niña and Australian weather usually weakens, with its strongest impacts normally confined to the northeast of the continent. During La Niña we typically see fewer and less intense heatwaves across much of eastern Australia, but the intensity of heat extremes in Western Australia is <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015JD023592">not very different </a>between La Niña and El Niño. The pattern of extreme heat in Western Australia and flooding in parts of Queensland is fairly typical of a La Niña summer, although temperatures over 50℃ are extremely rare. <img src="https://images.theconversation.com/files/440812/original/file-20220114-23-1b2bb55.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="men pump water from flooded street" /> Recent flooding in Queensland is also typical of La Nina summers. RAPID RELIEF TEAM <h2>Climate change is cranking up the heat</h2> Should these temperatures be a surprise? Sadly, no. Australia has warmed by <a href="http://www.bom.gov.au/state-of-the-climate/australias-changing-climate.shtml">around 1.4℃ since 1910</a>, well ahead of the <a href="https://www.giss.nasa.gov/research/news/20220113/">global average of 1.1℃</a>. In northern Australia, summer-average temperatures have not <a href="http://www.bom.gov.au/climate/change/#tabs=Tracker&tracker=trend-maps&tQ=map%3Dtmean%26area%3Daus%26season%3D1202%26period%3D1930">risen as much</a> as other parts of the country, because summers in the Top End have also got wetter. That’s in line with climate change models. When the conditions are right in the Pilbara, however, heat is significantly more extreme than it used to be. Heat events in the region have become <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020EF001924">more frequent, more intense, and longer-lasting</a>, just as in most other regions. Most of us have chosen not to live in Australia’s hottest areas. So you might think you don’t need to worry about 50℃ heatwaves. But as the climate continues to warm, heatwave conditions are expected to become much more common and extreme across the continent. In urban areas, roads and concrete soak up the sun’s heat, raising maximum temperatures by several degrees and making for dangerous conditions. Even if we keep global warming below 2℃ in line with the Paris Agreement, we can still expect to see our first <a href="https://science.anu.edu.au/news-events/news/melbourne-and-sydney-should-prepare-50-degree-days">50℃ days in Sydney and Melbourne</a> in coming years. In January 2020 the Western Sydney suburb of Penrith came very close, <a href="https://www.sbs.com.au/news/sydney-s-penrith-the-hottest-place-on-earth-amid-devastating-bushfires/990f7843-278b-4973-90ab-b6dcb01c97aa">reaching 48.9℃</a>. <img src="https://images.theconversation.com/files/440813/original/file-20220114-19-defesm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="man holds child in front of cooling mist machine" /> Sydney and Melbourne will experience 50℃ days in coming years. Joe Castro/AAP As you know, it’s going to be very hard to achieve even keeping global warming below 2℃, given the need to urgently slash greenhouse gas emissions in the next decade. As it stands, the world’s actions on emission reduction suggest we are actually on track for around <a href="https://climateactiontracker.org/global/cat-thermometer/">2.7℃ of warming</a>, which would see <a href="https://theconversation.com/theres-no-end-to-the-damage-humans-can-wreak-on-the-climate-this-is-how-bad-its-likely-to-get-166031">devastating consequences</a> for life on Earth. We already know what we need to do to prevent this frightening future. The stronger the action to reduce greenhouse gas emissions globally – including by major carbon emitting countries such as Australia – the less the world will warm and the less Australian heat extremes will intensify. That’s because the relationships between greenhouse gas emissions, <a href="https://www.nature.com/articles/nature16542">global temperatures</a> and <a href="https://www.nature.com/articles/s41598-017-12520-2">Australian heat extremes</a> are roughly linear. You may think Australians are good at surviving the heat. But the climate you were born in doesn’t exist any more. Sadly, our farms, wildlife, and suburbs will struggle to cope with the extreme heat projected for coming decades. Let’s work to make this 50℃ record an outlier – and not the new normal.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/174909/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/andrew-king-103126">Andrew King</a>, Senior Lecturer in Climate Science, <a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</a> This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/this-wa-town-just-topped-50-a-dangerous-temperature-many-australians-will-have-to-get-used-to-174909">original article</a>. Image: Shutterstock

Domestic Travel

Deforestation can raise local temperatures by up to 4.5℃ – and heat untouched areas 6km away

Forests directly cool the planet, like natural evaporative air conditioners. So what happens when you cut them down? In tropical countries such as Indonesia, Brazil and the Congo, rapid deforestation <a href="https://www.nature.com/articles/nclimate3250">may have accounted for</a> up to 75% of the observed surface warming between 1950 and 2010. <a href="https://iopscience.iop.org/article/10.1088/1748-9326/ac2fdc">Our new research</a> took a closer look at this phenomenon. Using satellite data over Indonesia, Malaysia and Papua New Guinea, we found deforestation can heat a local area by as much as 4.5℃, and can even raise temperatures in undisturbed forests up to 6km away. More than 40% of the world’s population live in the tropics and, under climate change, rising heat and humidity could push them into <a href="https://www.nature.com/articles/s41561-021-00695-3">lethal conditions</a>. Keeping forests intact is vital to protect those who live in and around them as the planet warms. <a href="https://images.theconversation.com/files/431859/original/file-20211115-13-g3akke.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/431859/original/file-20211115-13-g3akke.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="" /></a> Trees provide shade, habitat, and regulate the supply of clean water. Shutterstock <h2>Deforestation hot spots</h2> At the recent climate change summit in Glasgow, world leaders representing 85% of Earth’s remaining forests committed to ending, and reversing, <a href="https://ukcop26.org/glasgow-leaders-declaration-on-forests-and-land-use/">deforestation by 2030</a>. This is a crucial measure in our fight to stop the planet warming beyond the internationally agreed limit of 1.5℃, because forests store vast amounts of carbon. Deforestation releases this carbon – <a href="https://royalsocietypublishing.org/doi/full/10.1098/rstb.2019.0120">approximately 5.2</a> billion tonnes of carbon dioxide per year – back into the atmosphere. This accounts for nearly 10% of the global emissions from 2009-2016. Deforestation is <a href="https://www.science.org/doi/10.1126/sciadv.aax8574">particularly prevalent</a> in Southeast Asia. <a href="https://data.globalforestwatch.org/documents/14228e6347c44f5691572169e9e107ad/explore">We calculate</a> that between 2000 and 2019, Indonesia lost 17% of its forested area (26.8 million hectares of land), and Malaysia 28% of its forest cover (8.12 million hectares). Others in the region, such as Papua New Guinea, are considered “<a href="https://wwf.panda.org/discover/our_focus/forests_practice/deforestation_fronts_/">deforestation hot spots</a>”, as they’re at high risk of losing their forest cover in the coming decade. Forests in this region are cut down for a variety of reasons, including for expanding palm oil and timber plantations, logging, mining and small-scale farms. And these new types of land uses produce different spatial patterns of forest loss, which we can see and measure using satellites. <h2>What we found</h2> We already know forests cool the climate directly, and losing forest causes local temperatures to rise. But we wanted to learn whether the different patterns of forest loss influenced how much temperatures increased by, and how far warming spread from the deforested site into neighbouring, unchanged areas. To find out, <a href="https://iopscience.iop.org/article/10.1088/1748-9326/ac2fdc">we used</a> satellite images that measure the temperature of the land surface. As the illustration below shows, we measured this by averaging forest loss in rings of different widths and radius, and looking at the average temperature change of the forest inside the ring. <a href="https://images.theconversation.com/files/431019/original/file-20211109-27-mpcx2l.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/431019/original/file-20211109-27-mpcx2l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="Illustration of how temperature changes due to forest loss." /></a> How forest clearing near an unchanged area causes temperatures to rise. For example, if you consider a circle of forest that’s 4km wide, and there’s a completely deforested, 2km-wide ring around it, the inner circle would warm on average by 1.2℃. The closer the forest loss, the higher the warming. If the ring was 1-2km away, the circle would warm by 3.1℃, while at 4-6km away, it’s 0.75℃. These might not sound like big increases in temperature, but global studies show <a href="https://www.pnas.org/content/114/35/9326.short">for each 1℃ increase in temperature</a>, yields of major crops would decline by around 3-7%. Retaining forest within 1km of agricultural land in Southeast Asia could therefore avoid crop losses of 10-20%. These estimates are conservative, because we only measured the effect of forest loss on average yearly temperatures. But another important factor is that higher average temperatures <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011JD016382">usually create</a> higher temperature extremes, like those during heatwaves. And those really high temperatures in heatwaves are what put people and crops at most risk. Of course, forests aren’t normally cut down in rings. This analysis was designed to exclude other causes of temperature change, putting the effect of non-local forest loss in focus. <h2>Why is this happening?</h2> Forests cool the land because trees draw water from the soil to their leaves, where it then evaporates. The energy needed to evaporate the water comes from sunshine and heat in the air, the same reason you feel colder when you get out of a pool with water on your skin. A single tree in a tropical forest can cause <a href="https://www.sciencedirect.com/science/article/pii/S0959378017300134">local surface cooling equivalent</a> to 70 kilowatt hours for every 100 litres of water used from the soil — as much cooling as two household air conditioners. Forests are particularly good at cooling the land because their canopies have large surface area, which can evaporate a lot of water. When forests in tropical regions are cut down, this evaporative cooling stops, and the land surface warms up. This is not news to the people of Borneo. In 2018, researchers surveyed <a href="https://www.sciencedirect.com/science/article/pii/S0959378017314188">people in 477 villages</a>, and found they’re well aware nearby forest loss has caused them to live with hotter temperatures. When asked why forests were important to their health and the health of their families, the ability for trees to regulate temperature was the most frequent response. <a href="https://images.theconversation.com/files/431029/original/file-20211109-13-18wfaj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/431029/original/file-20211109-13-18wfaj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="Logging road" /></a> A logging road in East Kalimantan, Bornea: logged forest on the left, virgin/primary forest on the right. <a href="https://upload.wikimedia.org/wikipedia/commons/a/ab/Logging_road_East_Kalimantan_2005.jpg" class="source">Aidenvironment, 2005/Wikimedia Commons</a>, <a href="http://creativecommons.org/licenses/by-sa/4.0/" class="license">CC BY-SA</a> <h2>A climate change double whammy</h2> In many parts of the world, including the tropics and Australia, expanding farmland is a major reason for cutting down forest. But given hotter temperatures also reduce the productivity of farms, conserving forests might prove a better strategy for food security and for the livelihoods of farmers. If forests must be removed, there may be ways to avoid the worst possible temperature increases. For example, we found that keeping at least 10% of forest cover helped reduce the associated warming by an average of 0.2℃. Similarly, temperatures did not increase as much when the area of forest loss was smaller. This means if deforestation occurs in smaller, discontinuous blocks rather than uniformly, then the temperature impacts will be less severe. To help share these findings, <a href="https://treeheat.azurewebsites.net">we’ve built a web mapping tool</a> that lets users explore the effects of different patterns and areas of forest loss on local temperatures in maritime South East Asia. It helps show why protecting forests in the tropics offers a climate change double whammy – lowering carbon dioxide emissions and local temperatures together.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/163584/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/sally-thompson-1223399">Sally Thompson</a>, Associate professor, <a href="https://theconversation.com/institutions/the-university-of-western-australia-1067">The University of Western Australia</a>; <a href="https://theconversation.com/profiles/debora-correa-1288935">Débora Corrêa</a>, Research fellow, <a href="https://theconversation.com/institutions/the-university-of-western-australia-1067">The University of Western Australia</a>; <a href="https://theconversation.com/profiles/john-duncan-1288934">John Duncan</a>, Research fellow, <a href="https://theconversation.com/institutions/the-university-of-western-australia-1067">The University of Western Australia</a>, and <a href="https://theconversation.com/profiles/octavia-crompton-1246306">Octavia Crompton</a>, Postdoctoral researcher, Pratt School of Engineering, <a href="https://theconversation.com/institutions/duke-university-1286">Duke University</a> This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/deforestation-can-raise-local-temperatures-by-up-to-4-5-and-heat-untouched-areas-6km-away-163584">original article</a>. Image: Shutterstock

Travel Trouble

How rising temperatures affect our health

Global warming is accelerating, driven by the continuing rise in greenhouse gas emissions. Australia’s climate has warmed <a href="https://www.csiro.au/en/Showcase/state-of-the-climate">by just over 1°C since 1910</a>, with global temperatures on course for a <a href="https://public.wmo.int/en/media/press-release/wmo-climate-statement-past-4-years-warmest-record">3-5°C rise this century</a>. Australia is ahead of the global temperature curve. Our <a href="https://www.mja.com.au/journal/2018/208/7/climate-change-brief-overview-science-and-health-impacts-australia">average daily temperature</a> is 21.8°C – that’s 13.7°C warmer than the global average of 8.1°C. <a href="http://www.bom.gov.au/climate/change/about/extremes.shtml">Heat extremes</a> (days above 35°C and nights above 20°C) are now more frequent in Australia, <a href="http://www.bom.gov.au/state-of-the-climate/australias-changing-climate.shtml">occurring around 12%</a> of the time compared to around 2% of the time between 1951 and 1980. So what do high temperatures do to our bodies? And how much extra heat can people and our way of living tolerate? More scorchers ahead <a href="http://www.bom.gov.au/climate/current/statements/scs68.pdf">Australia’s summer of 2018-19</a> was <a href="http://www.bom.gov.au/climate/current/season/aus/archive/201902.summary.shtml">2.14°C warmer</a> than the 1961–90 average, breaking the previous record set in 2012–13 by a large margin. It included an unprecedented sequence of <a href="http://www.bom.gov.au/climate/current/statements/scs68.pdf">five consecutive days</a> with nationally averaged maximum temperatures above 40°C. The first half of <a href="https://www.ncdc.noaa.gov/sotc/global/201907/supplemental/page-1">2019 ranks as the equal second</a> hottest since records began for the world, and also <a href="http://www.bom.gov.au/climate/current/month/aus/summary.shtml">Australia</a>. The <a href="http://www.bom.gov.au/climate/outlooks/#/overview/summary">Bureau of Meteorology</a> (BOM) has warned this summer will be another scorcher. Hot dry northerly <a href="https://doi.org/10.1038/s41561-019-0431-6">winds tracking across drought-affected</a> New South Wales and Queensland have the capacity to deliver blistering heat and extreme fire risks to the southern states, and little relief is in sight for those in drought. Some rural Australians have <a href="http://www.bom.gov.au/climate/extreme/records.shtml">already been exposed to 50°C days</a>, and the major southern metro cities are set to do the same within the next decade or so. How our bodies regulate heat Like most mammals and birds, humans are <a href="http://www.sciencedirect.com/science/article/pii/S1095643306003047">endotherms</a> (warm-blooded), meaning our optimal internal operating temperature (approximately 36.8°C +/− 0.5) is <a href="http://dx.doi.org/10.1016/B978-0-12-386525-0.00060-3">minimally influenced by ambient</a> temperatures. Quietly sitting indoors with the air temperature about 22°C, we passively generate that additional 15°C to keep our core temperature at about 37°C. Even when the air temperature is 37°C, our metabolism continues to generate additional heat. This excess internal heat is shed into the environment through the evaporation of sweat from our skin. Temperature and humidity gradients between the skin surface and boundary layer of air determine the rate of heat exchange. When the surrounding air is hot and humid, heat loss is slow, we store heat, and our <a href="https://www.ncbi.nlm.nih.gov/pubmed/26184272">temperatures rises</a>. That’s why hot, dry air is better tolerated than tropical, humid heat: dry air readily absorbs sweat. A breeze appears refreshing by dislodging the boundary layer of saturated air in contact with the skin and allowing in drier air – thus speeding up evaporation and heat shedding. What happens when we overheat? Heat exposure becomes potentially lethal when the human body cannot lose sufficient heat to maintain a safe core temperature. When our core temperature reaches 38.5°C, most would feel fatigued. And the cascade of symptoms escalate as the core temperature continues to rise beyond the safe functioning range for our critical organs: the heart, brain and kidneys. Much like an egg in a microwave, protein within our body changes when exposed to heat.<a href="http://theconversation.com/how-heat-can-make-your-body-melt-down-from-the-inside-out-22042"></a> While some heat-acclimatised elite athletes, such as Tour de France cyclists, may tolerate <a href="https://bjsm.bmj.com/content/bjsports/53/7/426.full.pdf">40°C for limited periods</a>, this temperature is potentially lethal for most people. As a pump, the heart’s role is to maintain an effective blood pressure. It fills the hot and dilated blood vessels throughout the body to get blood to vital organs. Exposure to extreme heat places significant additional workload on the heart. It must increase the force of each contraction and the rate of contractions per minute (your heart rate). If muscles are also working, they also need an increased blood flow. If all this occurs at a time when profuse sweating has led to dehydration, and therefore lower blood volume, the heart must massively increase its work. The heart is also a muscle, so it too needs extra blood supply when working hard. But when pumping hard and fast and its own demand for blood flow is not matched by its supply, it can fail. Many heat deaths are recorded as heart attacks. High aerobic fitness levels offer some heat protection, yet athletes and fit young adults pushing themselves too hard also die in the heat. Who is more at risk? Older Australians are more vulnerable to heat stress. Age is commonly associated with poorer aerobic fitness and impaired ability to detect thirst and overheating. Obesity also increases this vulnerability. Fat acts as an insulating layer, as well as giving the heart a more extensive network of blood vessels to fill. The additional weight requires increased heat-generating muscular effort to move. Certain medications can lower heat tolerance by interfering with our natural mechanisms necessary to cope with the heat. These include drugs that limit increases in heart rate, lower blood pressure by relaxing blood vessels, or interfere with sweating. Core temperatures are increased by about half a degree during late stage pregnancy due to hormonal responses and increased metabolic rate. The growing foetus and placenta also demand additional blood flow. Exposure of the fetus to heat extremes can precipitate preterm birth and <a href="http://dx.doi.org/10.1289/ehp.125-A25">life-long health problems</a> such as congential heart defects. Won’t we just acclimatise? Our bodies can acclimatise to hot temperatures, but this process <a href="http://www.mdpi.com/1660-4601/12/7/8034">has its limits</a>. Some temperatures are simply too hot for the heart to cope with and for sweat rates to provide effective cooling, especially if we need to move or exercise. We’re also limited by our kidneys’ capacity to conserve water and electrolytes, and the <a href="http://www.mdpi.com/1660-4601/12/7/8034">upper limit to the amount of water</a> the human gut can absorb. Profuse sweating leads to fluid and electrolyte deficits and the resulting electrolyte imbalance can interfere with the heart rhythm. Mass death events are now occurring during heat waves in traditionally hot countries such as <a href="https://theconversation.com/a-heatwave-thats-too-hot-for-india-to-handle-with-more-to-come-42468">India</a> and Pakistan. This is when heat extremes approaching 50°C exceed the human body’s capacity to maintain its safe core temperature range. Heatwaves are hotter, more frequent and lasting longer. We can’t live life entirely indoors with air conditioning as we need to venture outdoors to commute, work, shop, and care for the vulnerable. People, animals and our social systems depend on this. Besides, on a 50°C day, air conditioning units will struggle to remove 25°C from the ambient air.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/123016/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> Written by Liz Hanna, Honorary Senior Fellow, Australian National University. Republished with permission of <a rel="noopener" href="https://theconversation.com/how-rising-temperatures-affect-our-health-123016" target="_blank">The Conversation</a>.

Body

Why is air colder the higher up you go?

Why is air colder the higher up you go? Shouldn’t it be hotter as you’re getting closer to the Sun? – Flynn, age 6, Sydney. Thank you Flynn, that’s a great question. A lot of people have probably wondered this. As you may know, hot air rises. So why is it so cold at the top of a mountain? Well, it helps if you imagine the ground here on Earth as a big heater. It keeps us warm, and if you move away from the heater you feel cold. So what “heats up” the heater? The light and warmth from the Sun. Scientists call this light and warmth “radiation”. Light and warmth travel from the Sun The light and warmth from the Sun travel through space towards Earth and pass through our atmosphere. (The “atmosphere” is what we call the swirling air that surrounds our planet.) But the atmosphere isn’t very good at holding onto the warmth from the Sun. The heat just slips straight through it. (For the adults reading: that’s because air at higher altitudes thins out as the gas particles expand and lose energy.) Eventually, the heat from the Sun hits the ground and the ground soaks it up. This especially happens in forests and oceans, which are very good at absorbing heat. Other places, like snow fields, are more likely to reflect the radiation – meaning it bounces back toward the Sun instead of being soaked up by the ground. Up, up, up The higher up you go, the further you are away from the “heater” that is keeping us all warm – the ground that has absorbed the warmth from the Sun. At the top of mountains, it can get so cold people could die within minutes without special protection. That’s because the air up there is just really bad at “holding onto” the radiation coming from the Sun, and the warmth passes straight through it on its journey toward the ground. And all the way up in space, there is a lot more radiation from the Sun, and astronauts wear special suits to protect themselves from it. But there’s also no air in space, which means there’s really nothing much at all to “hold onto” the warmth of the Sun and make the temperature around you feel warm. So if you were unlucky enough to be caught in space without a suit, you would freeze to death before the Sun’s radiation would get you. Written by Zoran Ristovski and Branka Miljevic. Republished with permission of <a href="https://theconversation.com/curious-kids-why-is-air-colder-the-higher-up-you-go-116822">The Conversation</a>.

Travel Tips

Extreme temperatures soar over 40C: Brace yourself for a heatwave today

Extreme heatwaves are set to make way across Victoria, South Australia, Tasmania and some parts of New South Wales today. Broken Hill is forecast to get up to 45 degrees today yet that’s not the most extreme brunt of heat Australians may be facing today. Melbourne is set to reach 42 degrees and the Mercury is forecast could hit 47 degrees near the Victorian border. Sydney’s west and Hobart, Tasmania will both be reaching for the air con as well with heat projected to hit at 39 degrees. A sticky day is expected for the Northwest in South Australia today, with temps to reach 49. Fires have been totally banned for the whole state of Victoria. Click below to see what these restrictions could mean for you. <blockquote class="twitter-tweet" data-lang="en"> Friday 4 January 2019 has been declared a day of TOTAL FIRE BAN for the whole State of Victoria. Plan ahead and understand what this means for you. Know what you can and can't do on a day of Total Fire Ban: <a href="https://t.co/Io6AlZ7Evh">https://t.co/Io6AlZ7Evh</a> <a href="https://twitter.com/hashtag/vicfires?src=hash&ref_src=twsrc%5Etfw">#vicfires</a> <a href="https://t.co/utTkH0rfwT">pic.twitter.com/utTkH0rfwT</a> — VicEmergency (@vicemergency) <a href="https://twitter.com/vicemergency/status/1080334467779092480?ref_src=twsrc%5Etfw">January 2, 2019</a></blockquote> Fortunately, the air con might not have to be on for the whole day though as temps are expected to cool down by the late afternoon. However, these cool wind changes could mean issues for firefighters trying to control blazes that may break out from the intense heat, a spokesperson for the CFA said. “The cool changes could make things very problematic,” they said. These winds could be up to 100km/h with the potential to widen fires attempting to be controlled. Forecasters are advising people who are especially susceptible to heatstroke to stay hydrated and remain indoors

Domestic Travel

Severe weather warnings in place as temperatures soar

Forecasters have warned Aussies of a “wild day of weather” as above-average temperatures, rain, 100km-plus gales and even blizzards are forecasted. Tasmania is expected to be hit with “vigorous and damaging” gusts of up to 100km/h. The Bureau of Meteorology has issued a severe warning for the Western, Upper Derwent Valley, South East and parts of East Coast, Central Plateau and Midlands areas today. <blockquote class="twitter-tweet" data-lang="en"> ⚠️ Severe Weather Warning issued for Damaging <a href="https://twitter.com/hashtag/Winds?src=hash&ref_src=twsrc%5Etfw">#Winds</a> for Western and Southern <a href="https://twitter.com/hashtag/Tasmania?src=hash&ref_src=twsrc%5Etfw">#Tasmania</a> for Wednesday morning and early afternoon. See <a href="https://t.co/lu3PDZ9GbE">https://t.co/lu3PDZ9GbE</a> for details and updates; <a href="https://twitter.com/hashtag/Hobart?src=hash&ref_src=twsrc%5Etfw">#Hobart</a> <a href="https://twitter.com/hashtag/weather?src=hash&ref_src=twsrc%5Etfw">#weather</a> <a href="https://t.co/lJW3P9PkP2">pic.twitter.com/lJW3P9PkP2</a> — Bureau of Meteorology, Tasmania (@BOM_Tas) <a href="https://twitter.com/BOM_Tas/status/1039311209135316992?ref_src=twsrc%5Etfw">September 11, 2018</a></blockquote> Last night a cold front crossed Tasmania overnight, followed by a trough to cross Tasmania this morning. The windy conditions will continue to Thursday in the North-West, with showers contracting to the West and easing during the day. Friday will be mostly fine, with temperatures heating back up to the high teens. Hobart is expected to reach a maximum of 15 degrees today and 17C tomorrow. The wild weather follows many states encountering a burst of warm weather yesterday. Yesterday, Townsville had a top 27C and will rise to 29C towards the end of the week. Brisbane will experience 24C today, which will rise to 27C on the weekend. Today, Sydneysiders will experience 28C in the CBD which will drop back to 22C the following day. Yesterday, South Australia also encountered wild winds, with winds of 80-85km/h hitting Cleve, Whyalla, Roseworthy, Edinburgh and Hindmarsh. Today, South Australia is forecasted a high of just 16C. The Northern Territory will continue to experience warm weather with a high of 33C today and 35C on Friday. In the west of the country in Perth, temperatures have already fallen and the cloudy skies are expected to continue until the weekend.

Domestic Travel

Heatwave alert: Scorching hot weather returns with a vengeance

After last week’s cool spell you’d be forgiven for thinking the worst of summer is finally behind us, but forecasts suggest it’s about to return with a vengeance, with parts of the country expected to face severe heatwaves in the coming days. Parts of Sydney and Brisbane are expected to hit the 40°C mark, with Canberra facing temperatures of 35°C and Melbourne and Adelaide not too far off. “There’s been a bit of a nice reprieve from that heat but it’s coming back again particularly for the south of the country,” Sky News Weather meteorologist Rob Sharpe told <a href="http://www.news.com.au/" target="_blank">news.com.au</a>. “In Adelaide, the heatwave is going to persist across much of the week. It won’t be quite as intense as the previous heatwave that crossed southeast Australia, but we’ll still see some pretty hot temperatures moving through,” he said. “In Adelaide, the long-term average for February is 28.5C but on Sunday they got to 34C and that will rise this week to the point they will have six days in a row above average.” But what’s driving these hot conditions? “The reason it will get so hot is a high pressure system is setting up in the Tasman Sea off the NSW coast. Because the winds travel anticlockwise around high pressure systems, we have north-westerly winds drawing heat from the north of the country down into the south and that’s where it will sit for a number of days,” Mr Sharpe said. Your capital city’s forecast: Adelaide High temperatures will peak at 39°C on Friday, with a cool change coming on the weekend. While temperatures will be high, humidity is expected to be low. Melbourne Temperatures will peak on Wednesday at 34°C, before steadying. Hobart Expect a high of 28°C on Wednesday before cooler weekend conditions. Canberra It’s going to be a warm week, with a peak of 35°C on Saturday. Sydney Temperatures in Sydney will heat 29°C, pushing almost 40°C out west. Brisbane Temperatures could rise to a high of 37°C on Sunday. Darwin Rains and high temperatures of 32°C are expected. Perth Expect a steady week of sunshine with a high of 33°C. Hero image credit: Twitter / Sky News

Domestic Travel

Heatwave: brace yourself for a hot and humid Australia Day long weekend

<div class="replay"> <div class="reply_body body linkify"> <div class="reply_body"> <div class="body_text "> Get your swimwear out, get your barbecue ready and maybe have a brolly handy – Australia Day is set to be a scorcher. Across the country, forecasts are predicting sweltering, humid conditions and potentially even rain and storms in Victoria and parts of NSW during the afternoon. “On Australia Day it will be hot across southern and south-eastern Australia, with heatwave conditions continuing over western NSW and northern South Australia,” Sky News Weather meteorologist Rob Sharpe told <a href="http://www.news.com.au/technology/environment/australia-day-weather-melbourne-sydney-brace-for-hot-humid-conditions/news-story/724e869d3f39db722b959b0fed76fd84" target="_blank">news.com.au</a>. “The heat is due to a pair of almost stationary troughs sitting over the south-east and the western inland of the country.” And the southern capitals are set to be hit, too. “Adelaide [is] forecast to exceed 40 degrees each day, and Melbourne above 35 degrees. Even Hobart is forecast to hit 35 on both Saturday and Sunday on the long weekend.” Perth and Hobart will see the most pleasant conditions, however, with each city expected to hit 28 and 27 degrees, respectively. “Darwin is the most likely to be wet, with showers and storms in the forecast,” Sharpe says. “Sydney should be warm and humid, with showers and storms a risk in the west. Just the chance of a shower or two each day in Brisbane across the long weekend with daily tops of 31C.” Here’s what each capital city can expect this long weekend. <ul> <li>Sydney – Australia Day: 30 degrees with a chance of showers, Saturday: 30 degrees, Sunday: 29 degrees.</li> <li>Melbourne – Australia Day: 35 degrees with possible afternoon showers, Saturday: 39 degrees with a chance of showers, Sunday: 39 degrees.</li> <li>Brisbane – Australia Day: 31 degrees with a chance of showers and storms followed by 31 degrees and showers on both Saturday and Sunday.</li> <li>Perth – Australia Day: 28 degrees, Saturday: 28 degrees, Sunday: 31 degrees.</li> <li>Adelaide – Australia Day: 40 degrees, Saturday: 42 degrees, Sunday: 42 degrees.</li> <li>Hobart – Australia Day: 27 degrees followed by 35 degrees and a chance of showers on both Saturday and Sunday.</li> <li>Canberra – Australia Day: 34 degrees and possible shower, Saturday: 32 degrees with showers, Sunday: 33 degrees with a chance of showers.</li> <li>Darwin – Australia Day, Saturday and Sunday: all 31 degrees with a chance of rain and storms.</li> </ul> Tell us in the comments below, what are your plans for Australia Day? Image credit: Bureau of Meteorology. </div> </div> </div> </div>

News

Extreme heat warnings across Australia this weekend

Australians are being warned to <a href="http://www.oversixty.com.au/news/news/2018/01/severe-temperature-warning-issued-for-australia/" target="_blank">brace themselves for a scorching hot weekend</a>, with extreme temperature warnings in place across the country. South Australia and Victoria are already in the thick of a heatwave that’s seen Melbourne temperatures soar to 40°C and Tour Down Under official to shorten today’s cycling leg. Health experts have also issued dire warning for tennis players competition in the Australian Open, with some saying they “could die” under the extreme conditions. Dr Liz Hanna, of the Climate Change Institute at the Australian National University and the Climate and Health Alliance, told <a href="http://www.news.com.au/" target="_blank">news.com.au</a>, “(The temperatures players face) are a lot hotter than recorded and we know with tennis players – particularly when they’re playing at their full capacity – their muscles are generating an enormous amount of additional heat. “They’re at very high risk of overheating and that is potentially lethal. The worst case scenario is that somebody would succumb to severe injury.” <blockquote class="twitter-video"> ⚠SEVERE WEATHER UPDATE: Hot weather and <a href="https://twitter.com/hashtag/fire?src=hash&ref_src=twsrc%5Etfw">#fire</a> danger in South Australia and southeastern States. Video current at 1.30pm AEDT Thurs 18 Jan. Forecasts at <a href="https://t.co/vJmkTXbr9Z">https://t.co/vJmkTXbr9Z</a><a href="https://twitter.com/SAHealth?ref_src=twsrc%5Etfw">@SAHealth</a> <a href="https://twitter.com/CFSAlerts?ref_src=twsrc%5Etfw">@CFSAlerts</a> <a href="https://twitter.com/NSWHealth?ref_src=twsrc%5Etfw">@NSWHealth</a> <a href="https://twitter.com/NSWRFS?ref_src=twsrc%5Etfw">@NSWRFS</a> <a href="https://twitter.com/CFA_Updates?ref_src=twsrc%5Etfw">@CFA_Updates</a> <a href="https://twitter.com/vicemergency?ref_src=twsrc%5Etfw">@VicEmergency</a> <a href="https://twitter.com/tasalert?ref_src=twsrc%5Etfw">@TasAlert</a> <a href="https://twitter.com/TasFireService?ref_src=twsrc%5Etfw">@TasFireService</a> <a href="https://twitter.com/hashtag/heatwave?src=hash&ref_src=twsrc%5Etfw">#heatwave</a> <a href="https://t.co/zQMgIDsmSo">pic.twitter.com/zQMgIDsmSo</a> — Bureau of Meteorology, Australia (@BOM_au) <a href="https://twitter.com/BOM_au/status/953831467007713281?ref_src=twsrc%5Etfw">January 18, 2018</a></blockquote> The Bureau of Meteorology (BOM) says the string of hot days is the result of a hot air mass being dragged down from Central Australia and raising temperatures in the eastern states. And BOM forecaster Jonathan How says there is more pain coming. “Particularly Sydney is going to see some very hot temperatures in the western suburbs,” Mr How told <a href="http://www.news.com.au/" target="_blank">news.com.au</a>. “Penrith and Richmond have already seen eight days above 40°C so far this summer so they’re well on the way to beating the all-time record of 12 days over 40°C.” Tips for handling a heat wave: <ul> <li>Drink plenty of water</li> <li>Eat cold meals</li> <li>Avoid sport and strenuous activity</li> <li>Stay in shade or air-conditioned buildings</li> </ul> What are your thoughts? Have you been coping with the heat?

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Extreme heat warnings across Australia this weekend

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