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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

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

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

Barty's brilliantly blunt take on Tokyo heat

As the weather in Tokyo reached the mid-30s, many players have been complaining about being forced to play at the peak of the heat. But, Aussie tennis star Ash Barty had no qualms about the inclement weather and gave a blunt response when asked for her opinion on the conditions. “We’re Aussies, mate. We’re alright,” she told News Corp after her and Storm Sanders’ loss in the women’s doubles against Czech pair Barbora Krejcikova and Katerina Siniakova. Meanwhile, Spain’s Paula Badosa was taken off the court in a wheelchair after collapsing from heat exhaustion during her quarter-final match against Marketa Vondrousova. <blockquote class="twitter-tweet"> Suspect scenes like these may have played a part in the decision of Olympic organisers to take tennis out of the worst of the heat. Paula Badosa taken off court in a wheelchair with heat exhaustion. <a href="https://t.co/I6GZ4Uq7KY">pic.twitter.com/I6GZ4Uq7KY</a> — James Gray (@jamesgraysport) <a href="https://twitter.com/jamesgraysport/status/1420352664236404739?ref_src=twsrc%5Etfw">July 28, 2021</a></blockquote> “It was a shame to finish my participation in this way,” Badosa said. “The conditions have been demanding from day one. We tried to adapt as best as possible but today the body has not responded as needed. “I have suffered a heat stroke as you all have seen and I did not feel ready to continue.” Russian Daniil Medvedev also struggled with the soaring temperatures during his third round win over Fabio Fognini. Medvedev took two medical timeouts and asked who would be responsible for his death. “I can finish the match but I can die,” he told chair umpire Carlos Ramos when asked if he could continue. “If I die, are you going to be responsible?” <blockquote class="twitter-tweet"> Still alive🥵　<a href="https://twitter.com/Tokyo2020?ref_src=twsrc%5Etfw">@Tokyo2020</a> <a href="https://twitter.com/Olympics?ref_src=twsrc%5Etfw">@Olympics</a> <a href="https://t.co/xEJqMGUNsq">pic.twitter.com/xEJqMGUNsq</a> — Daniil Medvedev (@DaniilMedwed) <a href="https://twitter.com/DaniilMedwed/status/1420306048758554629?ref_src=twsrc%5Etfw">July 28, 2021</a></blockquote> “I just had darkness in my eyes, like between every point I didn’t know what to do to feel better. “I was bending over and I couldn’t get my breathing together. I was ready to just fall down on the court.” After complaints from world No. 1 Novak Djokovic and several other plays, organisers have since moved the start of play to 3pm local time to offer players some added protection against the heat.

News

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>.

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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

Weather warning: The first heatwave of summer set to scorch Australia

Experts have warned to take extra care as scorching heat is set to hit Australia on Friday, with the hottest November day in three years predicted. Very high temperatures were already expected but, hot dessert air coming to the south and south-eastern capitals could make for an even more sweltering day, reports <a rel="noopener" href="https://www.news.com.au/technology/environment/hottest-november-day-for-three-years-predicted-as-desert-heat-mass-creeps-towards-four-capitals/news-story/f9a0f2d29e522496fdf5ce159e75d5e4" target="_blank" title="news.com.au">news.com.au</a>. “We’re expecting the hottest temperatures since early 2018 between Wednesday and Friday and some of highest maximum November temperatures for up to three years,” Tom Saunders, meteorologist for Sky News Weather, predicted. NSW, Queensland and South Australia could be hit the hardest with inland areas possibly topping 40C. Sydney may experience temperatures of over 38C and Adelaide 36C. It’s a huge leap in average temperatures for November possibly topping an increase of 10C. But the heat is due to ramp up today with a burst of hot air from inland Queensland moving down to southern states. Adelaide is expected to hit predicted 36C, Port Augusta 39C and the heat will top 40C in the Northern Territory. In Melbourne’s CBD it will be a hot one at 33C, but on Friday, NSW will be one of the hardest hit states, with air conditioners no doubt on overload with an expected 37C and in the western suburbs 40C. If temperatures do crack 37C in Sydney, it will make a record for November as the hottest day in three years. The NSW coast including Sydney is expected to experience a low intensity heatwave according to the Bureau of Meteorology, from Thursday through to Saturday. But if you live in Brisbane, Perth or Hobart you’ll be better off with expected temperatures of 29C to the low-30s, the mid-20s, and 24C respectively. Experts have warned to take extra care during the heatwave particularly the elderly, children, and pets. “Heat can kill which is why it’s so important to stay hydrated and look out for the elderly, the young and pets,” Alan Morrison, NSW Ambulance chief superintendent, told news.com.au. The site reports that almost 4500 people were treated by paramedics for dehydration between December 2017 and March 2018, and many more for heat exhaustion. We may also expect bushfire warnings. “Winds will average 40km/h so that could mean severe fire danger in the Mallee and some parts of South Australia, and fires will be fast moving and difficult to control,” said Saunders. But look forward to the weekend with a cool change expected.

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

Severe temperature warning issued for Australia

After parts of the country started the year with stinking hot conditions you’d be forgiven for thinking we’d already seen the worst of summer in 2018, but if the Bureau of Meteorology’s (BOM) forecast is anything to go by, we haven’t seen anything yet. A severe temperature warning has been issued for parts of Australia, with the temperatures expected to regularly exceed 40°C over the coming weeks. The BOM forecasts a heatwave to hit Australia’s south east from Thursday this week which will affect Sydney, Brisbane, Canberra, Melbourne and Adelaide. “Thursday is when it gets stinking hot and it will stay hot well into next week,” Sky News Weather meteorologist Tristan Meyers told <a href="http://www.news.com.au/" target="_blank">News.com.au</a>. “We’ve seen so many heatwaves and now we’re in for yet another one with temperatures rising across broad areas of South Australia, NSW and Victoria above 40C. The heat is well and truly back. “We’ll see a severe intensity heatwave gripping South Australia by Wednesday which will push temperatures on Thursday to 41°C.” <blockquote class="twitter-tweet"> Low to severe intensity <a href="https://twitter.com/hashtag/heatwave?src=hash&ref_src=twsrc%5Etfw">#heatwave</a> conditions developing across southeast Australia from mid-week with hot days and warm nights ahead. <a href="https://t.co/HAQ5Af1M8e">pic.twitter.com/HAQ5Af1M8e</a> — Bureau of Meteorology, Australia (@BOM_au) <a href="https://twitter.com/BOM_au/status/952730792832184320?ref_src=twsrc%5Etfw">January 15, 2018</a></blockquote> So when is the heat going to hit your city? Sydney, Melbourne and Canberra are gearing up for a dramatic rise in temperatures on Thursday, with hot conditions expected to continue into the weekend. Adelaide looks like it’s going to cop the worst of the heatwave, with temperatures peaking at 41°C on Thursday, while conditions in Perth with be comparatively milder. It’s going to be sunny in Brisbane without being as scorching as it is in the southern states, and Darwin residents can expect a warm week with some storms. By comparison, people living in Hobart are expected to enjoy a relatively mild week, with temperatures peaking at 29°C on Thursday, before lowering for the weekend. What are your thoughts? How have you handled the extreme heat? Hero image credit: Bureau of Meteorology

News

"Severe warning": Extreme heatwave to hit all capital cities as temperatures soar

After a slow start to summer that saw freezing cold nights, hail and torrential rain, summer has finally arrived, with a scorching heatwave set to sweep the country in the coming week. The temperature is set to soar above 30C across all capital cities, except Hobart, in the days ahead. But even Tasmania won’t be far off the 30C mark. Sydney will see the mercury soaring through the 30s by mid-week, Perth could get to 35C, Melbourne to 36C on Wednesday and Adelaide could potentially sweat through a hot 43C on Wednesday. Even the nation’s capital Canberra is set to swelter with temps ranging from low to mid 30s in the coming week. There is severe to extreme heatwave conditions forecasted for the Kimberley and Top End, with NT capital Darwin looking at temperatures of 35C all week. Brisbane is looking at highs of 20s early in the week followed by a sunny 32C on Friday and Saturday. <blockquote class="twitter-tweet"> The heat wave is expected to continue over the <a href="https://twitter.com/hashtag/TopEnd?src=hash&ref_src=twsrc%5Etfw">#TopEnd</a> and extend to much of the <a href="https://twitter.com/hashtag/NorthernTerritory?src=hash&ref_src=twsrc%5Etfw">#NorthernTerritory</a> early this week. Stay hydrated! Some respite towards the end of the week as showers return. Forecasts at <a href="https://t.co/PZqLmStPfd">https://t.co/PZqLmStPfd</a>. <a href="https://t.co/Q6zpiEhvmE">pic.twitter.com/Q6zpiEhvmE</a> — Bureau of Meteorology, Northern Territory (@BOM_NT) <a href="https://twitter.com/BOM_NT/status/939658412970913794?ref_src=twsrc%5Etfw">December 10, 2017</a></blockquote> Bureau of Meteorology meteorologist Ashleigh Langey said NSW would reach peak temperatures on Thursday, followed by a short cool change on Friday. “Over the next couple of days there will be a high pressure system influencing the state with pretty warm conditions. From Tuesday onwards it looks like we have got a low intensity heatwave developing, and by Thursday it will be a severe heatwave in parts of the state. “There will be clear skies as well, which means things will heat up.” “The hottest day in Sydney will be Thursday, and we’re forecasting 34C (and hotter in the west). On Friday it will cool down to 27C because we have a southerly change moving through that will cool things down a bit,” she said. ”Even on Friday in the west of NSW it will still be quite warm. On Saturday it’s heating back up with 33C in Sydney.” The end of the week will see a nationwide cool-off, but next week is set to experience similar heat.

Domestic Travel

Severe warning as extreme temperatures set to rise this summer

With temperatures climbing steadily as we head into what is predicted to be one of Australia’s hottest summers, we look at the signs of heat stroke you need to be aware of (and what you can do to keep yourself safe). Heat stroke is a life-threatening condition where the body's temperature rises so much that your body stops sweating. The body loses its ability control temperature and if left untreated, heat stroke can cause damage to your vital organs included your brain, heart, kidneys and muscles. Who is at risk Extreme heat can affect everyone, but older people, young children and people with chronic health conditions are most at risk. People taking certain medications, like blood-pressure lowing medications and antidepressants are also at risk. Signs and symptoms Heat stroke generally occurs when you have been in a hot, humid and perhaps poorly ventilated environment for a prolonged time. According to <a href="http://stjohn.org.au/assets/uploads/fact%20sheets/english/FS_heat.pdf">St John Ambulance Australia</a>, signs to be aware of include: <ul> <li>high body temperature of 40°C or more</li> <li>flushed, dry skin</li> <li>pounding, rapid pulse that gradually weakens</li> <li>headache and irritability</li> <li>nausea, vomiting</li> <li>visual disturbances</li> <li>faintness, dizziness, confusion</li> <li>loss of consciousness</li> <li>seizures</li> </ul> What to do <ol> <li>Follow the first aid regime DRSABCD (Danger Response Shout Airways Breathing Compression Defibrillation).</li> <li>Call triple zero (000) for an ambulance.</li> <li>Move the patient to a cool place with circulating air.</li> <li>Help the patient to sit or lie down in a comfortable position.</li> <li>Remove almost all the patient’s clothing, and loosen any tight clothing.</li> <li>Apply a cold pack to areas of large blood vessels such as the neck, groin and armpits, to accelerate cooling.</li> <li>If possible, cover the patient with a wet sheet and fan to increase air circulation. Stop cooling when the patient feels cold to touch.</li> <li>If patient is fully conscious and is able to swallow, give them cool water to sip.</li> </ol>

Body

Winter temperatures to soar to 32°C next week

At a time of the year where we’re used to reaching for a warm jacket, parts of Australia have been warned to brace for the warmest winter temperatures in almost a decade. Temperatures in Brisbane are expected to reach the mid-30s, with balmy weather expected for much of Queensland and NSW over the course of the week. Cold fronts that are bringing cooler temperatures to Western Australia are running out of puff before they reach the east coast, or moving to Melbourne instead, which is expected to be the main cause of the above average temperatures. The weather will be a little more seasonal in South Australia, Victoria and WA. How are you finding the weather this winter? Image credit: Sky News Australia

Domestic Travel

Brace yourself for an extreme temperature surge this weekend

Australians have been warned to brace themselves for a surge in temperatures this weekend that will make some parts of the country feel as though they’re in the middle of summer. The weekend Sydney temperature is forecast to hit the average for a December day, with the mercury set to soar to October averages in Brisbane and Adelaide. Perth temperatures will feel like late September, with Melbourne, Hobart and Canberra also set to face unseasonably warm conditions over the weekend. And while many people are probably enjoying the relief from the winter chill, meteorologists have warned that we’re set for one of our driest years on record. Tom Saunders, Sky News Weather meteorologist told <a href="http://www.news.com.au/" target="_blank">News.com.au</a>, “At first glance, it’s quite surprising this winter has been so dry considering the usual suspects of El Nino or the Indian Ocean Dipole (climate drivers) are not present. “Rather than the global drivers of weather variability, it has been local conditions which have caused the dry winter.” What’s your take? Are you concerned about this erratic weather we’ve been having? Or do you appreciate the warm change from the winter chill? Hero image credit: Sky News / News.com.au

Domestic Travel

Temperatures set to plummet this weekend

A series of cold fronts are sweeping towards the east of the country bringing huge drops in temperature. On Sunday, Sydney is forecasted to see its coldest morning in almost two years. Hobart and Melbourne will face even colder temperatures. Areas such as Orange, in the NSW Central West, are expected to be hit by the cold fronts with temperatures plummeting to -6C on Sunday, while Canberra is expected to have a low of -7C. The wind chill factor could also reduce temperatures by 10C. Jordan Notara from the Bureau of Meteorology said, “It's going to be a chilly morning, with temperatures expected to be on the cooler end of the scale.” "The reason behind the drop is because Sydney will experience a series of fronts, with one coming down on Sydney on Saturday night. "A high pressure system will also cover the whole state, with clear skies and air measures giving it a cool change." On Saturday, Sydney will see a mostly sunny day with a minimum of 10C and a top of 18C, before plummeting to 5C and a top of 17C on Sunday. Melbourne is expected to have showers all weekend and face a minimum of 4C on Sunday morning and a top of 13C. Hobart will face the cold this weekend with both Saturday and Sunday morning’s forecasted to be 3C. Canberra will be Australia’s coldest capital city with Sunday morning facing a low of -7C. Adelaide will see a low of 3C on Saturday but will struggle to get above 11C making it the chilliest day. Image credit: Sky News Weather

News

Does water temperature make a difference when you wash your hands?

A US study has discovered that washing your hands with cold water is as effective as washing them with warm water. Scientists from Rutgers University coated the hands of 20 participants in a harmless strain of bacteria and then had them wash their hands with varying temperatures of water. The participants either washed their hands at 15°C, 26 °C or 38 °C with a 0.5ml, 1ml or 2ml of antimicrobial soap. The temperature of the water was found to make no difference to how the bacteria was washed off. “People need to feel comfortable when they are washing their hands but as far as effectiveness, this study shows us that the temperature of the water used didn’t matter,” said <a href="http://news.rutgers.edu/research-news/handwashing-cool-water-effective-hot-removing-germs/20170529#.WTXluWiGOUm" target="_blank">Professor Donald Schaffner</a>, a Rutgers specialist in food science. The study, published in the <a href="http://jfoodprotection.org/doi/full/10.4315/0362-028X.JFP-16-370" target="_blank">Journal of Food Protection</a>, also discovered how long the average person should wash their hands to remove bacteria. “We learned even washing for 10 seconds significantly removed bacteria from the hands,” said Schaffner However, those who work in industries such as restaurants or hospitals, should wash their hands for a greater length of time. US health guidelines advise hands to be washed with water that is warmer than 38°C though there is not much scientific proof that backs this up. The Rutgers team believe their findings could help the environment. “We are wasting energy to heat water to a level that is not necessary,” Schaffner said. The researchers hope more work will be done to establish the prime conditions for washing hands such as looking at the time you spend lathering them in soap and how you dry them. Do you wash your hands with warm or cold water? Let us know in the comments below.

Body

What temperature should your laundry be washed in?

It’s a well-rehearsed debate – hot water or cold water when washing your laundry? Those who swear by hot water will strike home the point that heat kills bacteria, and therefore gives a more effective wash. On the other side, we have the cold water spokespeople, whose main argument is that hot water not only shrinks your clothes but also drowns your power bill with the energy needed to heat the water. So what temperature should we actually be washing our laundry in? Colorado-based care expert Steve Boorstein told Real Simple: “Technological advances in both machines and detergents, and not just cold specific detergents, have made cold washing a highly effective option.” Energywise says washing on a warm cycle can use up to 10 times as much energy as a cold wash, which is an extra 20 to 40 cents for every single wash. Protein stains, such as sweat or blood, can set in when washed in hot water, Boorstein says. But some dry-fit workout clothes tend to still smell after a cold wash cycle, which is when Boorstein suggests giving them a cold wash pre-rinse within 20 minutes of a workout before putting them through a warm wash. Consumer Reports says “don’t bother” with hot water. Consumer tests over the past 15 years have found front loaders’ and high-efficiency top loaders’ warm wash cycles have declined by 15 degrees, and detergents have adjusted accordingly. Persil NZ suggests there are three forms of energy needed for the right balance to effectively remove soil from fabric: thermal energy, gained from hot or warm water; mechanical energy, from the machine’s action; and chemical energy, supplied from the detergent used. In general, the company says although all detergents can be used in cold, warm or hot water, the effectiveness of the detergent will decrease as the water temperature decreases. Optimal temperature should be decided through a number of factors, including the amount of dirt, type of fabric and the likelihood of colour running, all of which will be outlined and given a temperature recommendation on the care label. First appeared on <a href="http://stuff.co.nz/" target="_blank">Stuff.co.nz.</a> Related links: <a href="http://www.oversixty.com.au/health/body/2016/08/5-non-diet-based-reasons-you-are-bloated/">5 non-diet based reasons you’re bloated</a> <a href="http://www.oversixty.com.au/health/body/2016/05/foods-to-eat-to-beat-bloating/">10 foods to eat to beat bloating</a> <a href="http://www.oversixty.com.au/health/body/2015/12/bloating-food/">The best and worst foods for bloating</a>

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Does water temperature make a difference when you wash your hands?

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