Limiting Warming to 2°C Would Prevent ‘Worldwide Increases’ in Heat-Related Deaths
By Daisy Dunne
Restricting global warming to 2°C above pre-industrial levels would prevent large increases in temperature-related deaths across much of the globe, a new study finds.
And keeping warming to 1.5°C—the aspirational target of the Paris agreement—would further limit the number of people dying from temperature extremes in some parts of the world, including in southeast Asia and southern Europe.
However, in some countries with a cooler climate, such as the UK, Ireland and Japan, overall temperature-related deaths would be higher at 1.5°C of warming than 2°C. This is because the additional 0.5°C of warming is expected to bring a bigger drop in winter deaths than the increase in deaths in hot summers, the researchers say.
The findings—which draw on data taken from 451 locations in 23 countries—show that, overall, taking steps to meet the 1.5°C limit could prevent "a hell of a lot of people" from dying as a result of temperature extremes in tropical countries, a study author tells Carbon Brief.
During a heatwave, the number of "heat-related deaths"—whereby exposure to heat either causes or significantly contributes to a death—tends to increase. For example, research shows that, during a heatwave, the risk of death from a heart attack is higher. Heatwaves are also associated with increased rates of suicide.
However, research also suggests that, as temperatures warm, numbers of "cold-related" deaths—which are caused by exposure to cold weather and winter illnesses—could decrease in some regions. Whether or not this "cold effect" could partially offset the expected rise in heat-related deaths has long been debated by scientists.
The new study, published in Climatic Change Letters, seeks to solve this conundrum by comparing the expected number of heat- and cold-related deaths in 23 countries under different levels of global warming.
To do this, they subtracted the expected fall in cold-related deaths from the expected rise in heat-related deaths for each country. This gave them an overall measure of how warming is likely to affect the number of "temperature-related" deaths.
The results show that, in many world regions, the number of temperature-related deaths is expected to "significantly increase"—despite decreases in cold-related deaths—if warming is not limited to 2°C. In their research paper, the authors say:
"Our results suggest that limiting warming below 2C could prevent large increases in temperature-related mortality in most regions worldwide."
For some regions, limiting warming to 1.5°C rather than 2°C would further prevent a rise in temperature-related deaths, says study author Dr. Dann Mitchell, a researcher in climate change and health from the University of Bristol. He told Carbon Brief:
"One major point from the study is that southeast Asia is the region that will be most severely hit by a net increase in deaths under higher levels of warming. Vietnam, in particular, is expected to experience a 2% increase in net deaths under 2C of warming, rather than 1.5C. That 2% is going to be a hell of a lot of people."
For the study, the researchers used data from the Multi-Country Multi-City Collaborative Research Network—which details the historical relationship between temperature and mortality in 451 locations across 23 countries.
This information was used to inform a set of global climate models—which produced projections of temperature-related mortality under 1.5°C, 2°C, 3°C and 4°C of global warming.
The models assumed that the current wealth and population of each country remained the same under future levels of global warming.
Under high levels of global warming, temperature-related mortality is likely to increase overall in many regions, the authors say:
"Under more extreme scenarios, most regions could experience considerably larger heat-mortality risks that would not be balanced by the projected decreases in cold-related excess mortality."
For example, under 4°C of warming, populations in southern parts of Europe and east Asia are projected to experience a 4-9 percent increase in heat-related deaths when compared to 1.5°C.
However, when looking at the difference in temperature-related deaths between 1.5 and 2°C, the picture is more "mixed," the researchers say.
The chart below shows the expected difference in temperature-related deaths between the 1.5 and 2°C scenarios. On the chart, red shows the expected increase in heat-related deaths for each country, blue shows the expected decrease in cold-related deaths and black diamonds mark the overall "net" number of deaths.
(If a diamond is on the right-hand side of the chart, it means the net number of deaths is expected to be lower under 1.5 than 2°C. However, if it is on the left-hand side, it shows that the net number of deaths is expected to be higher under 1.5 than 2°C for that country.)
Expected difference in temperature-related deaths between scenarios of 1.5 and 2°C of global warming above pre-industrial levels for 23 countriesVicedo-Cabrera et al. (2018)
The results show how the number of temperature-related deaths in southeast Asia, such as the Philippines, Thailand and Vietnam, and in southern Europe, such as Italy and Spain, would be smaller under 1.5 than 2°C.
For Vietnam, the number of heat-related deaths is expected to be around 2 percent lower under 1.5°C in comparison to 2°C. For Italy and Spain, the number of heat-related deaths is expected to be around 1 percent lower.
However, in some cooler regions, including in the UK, Ireland and Japan, the net number of deaths is expected to be higher under 1.5 than 2°C. This is because, in these regions, the additional 0.5°C of warming reduces more cold-related deaths than it increases heat-related ones.
In the UK, the net number of deaths is expected to be around 0.25 percent higher under 1.5°C than 2°C. In Ireland, the net number of deaths could be around 0.5 percent higher under 1.5°C.
The amount of regional warming is also important. For example, in Australia, the number of heat-related deaths is expected to be smaller than in other parts of Asia because temperature increases are expected to be milder, the researchers say.
In their research paper, however, the researchers caution that many of their results come with a large degree of statistical uncertainty (shown with black lines on the chart). The authors said:
"We also observe a large uncertainty in our estimates, particularly those for the next impacts and more extreme scenarios."
This uncertainty stems from variability in the climate models and a lack of data availability in some regions, they say.
Although not all regions would see fewer temperature-related deaths under 1.5°C than 2°C, this does not mean than 2°C should be considered a "safe" temperature limit, the researchers say.
One reason for this is that some regions that are expected to be the most vulnerable to heat-related deaths, such as southeast Asia, are also the least likely to be able to adapt to climate change, the researchers said:
"These regions include the most populated areas worldwide and, in general, the most vulnerable to climate change, with a limited capacity for adaptation due to lack of infrastructural, financial and technological resources."
In addition, comparing cold- and heat-related deaths may not give "the full picture" of how climate change will impact mortality, Mitchell said:
"Heat-related deaths tend to be very fast, caused by factors such as heart failure, or linked to social factors, such as suicide. On the other hand, cold-snaps lead to a very different sort of mortality. People who die from cold-related deaths can spend two to three weeks in hospital."
The differences between cold- and heat-related deaths mean they require different types of healthcare, Mitchell says. Because of this, the costs incurred from heat-related deaths may not be offset by a reduction in cold-related deaths. He said:
"The next stage of our research will be to look at the two metrics separately."
Record-Melting Fall Heat Wave Bakes Southern California https://t.co/VzjWlYqDgt @worldresources @tcktcktck— EcoWatch (@EcoWatch)1509069006.0
Reposted with permission from our media associate Carbon Brief.
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Farmers are the stewards of our planet's precious soil, one of the least understood and untapped defenses against climate change. Because of its massive potential to store carbon and foundational role in growing our food supply, soil makes farming a solution for both climate change and food security.
Soil can act as a natural "carbon sink." Climate Central, 2019
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By Shelly Miller
The vast majority of SARS-CoV-2 transmission occurs indoors, most of it from the inhalation of airborne particles that contain the coronavirus. The best way to prevent the virus from spreading in a home or business would be to simply keep infected people away. But this is hard to do when an estimated 40% of cases are asymptomatic and asymptomatic people can still spread the coronavirus to others.
It’s All About Fresh, Outside Air<p>The safest indoor space is one that constantly has lots of <a href="https://www.epa.gov/indoor-air-quality-iaq/how-does-outdoor-air-enter-building" target="_blank">outside air</a> replacing the stale air inside.</p><p>In commercial buildings, <a href="https://www.ncbi.nlm.nih.gov/books/NBK143277/" target="_blank">outside air is usually pumped in</a> through heating, ventilating and air-conditioning (HVAC) systems. In <a href="https://www.epa.gov/indoor-air-quality-iaq/how-does-outdoor-air-enter-building" target="_blank">homes, outside air gets in</a> through open windows and doors, in addition to seeping in through various nooks and crannies.</p><p>Simply put, the more fresh, outside air inside a building, the better. Bringing in this air dilutes any contaminant in a building, whether a virus or a something else, and <a href="https://doi.org/10.1111/j.1600-0668.2010.00703.x" target="_blank">reduces the exposure of anyone inside</a>. Environmental engineers like me quantify how much outside air is getting into a building using a measure called the <a href="https://doi.org/10.1038/jes.2013.30" target="_blank">air exchange rate</a>. This number quantifies the number of times the air inside a building gets replaced with air from outside in an hour.</p><p>While the exact rate depends on the number of people and size of the room, most experts consider roughly <a href="https://doi.org/10.1034/j.1600-0668.2002.01145.x" target="_blank">six air changes an hour</a> to be good for a 10-foot-by-10-foot room with three to four people in it. In a pandemic this should be higher, with one study from 2016 suggesting that an exchange rate of nine times per hour <a href="https://doi.org/10.1177%2F1420326X16631596" target="_blank">reduced the spread of SARS, MERS and H1N1</a> in a Hong Kong hospital.</p><p>Many buildings in the U.S., <a href="https://doi.org/10.1111/ina.12403" target="_blank">especially schools</a>, do not meet recommended ventilation rates. Thankfully, it can be pretty easy to get more outside air into a building. Keeping <a href="https://doi.org/10.1016/S0960-1481(99)00012-9" target="_blank">windows and doors open</a> is a good start. Putting a box fan in a window blowing out can greatly increase air exchange too. In buildings that don't have operable windows, you can change the mechanical ventilation system to increase how much air it is pumping. But in any room, the more people inside, the faster the air should be replaced.</p>
Using CO2 to Measure Air Circulation<p>So how do you know if the room you're in has enough air exchange? It's actually a pretty hard number to calculate. But there's an easy-to-measure proxy that can help. Every time you exhale, you <a href="https://doi.org/10.1111/ina.12383" target="_blank">release CO2</a> into the air. Since the coronavirus is most often spread by breathing, coughing or talking, you can use <a href="https://pdfs.semanticscholar.org/dd7e/b2870c38f70e5285e5118ed6f158c091f7cf.pdf" target="_blank">CO2 levels</a> to see if the room is filling up with potentially infectious exhalations. The CO2 level lets you estimate if enough fresh outside air is getting in.</p><p>Outdoors, CO2 levels are just above 400 parts per million (ppm). A well ventilated room will have around <a href="https://doi.org/10.1111/j.1600-0668.1999.00003.x" target="_blank">800 ppm of CO2</a>. Any higher than that and it is a sign the room might need more ventilation.</p><p>Last year, researchers in Taiwan reported on the <a href="https://doi.org/10.1111/ina.12639" target="_blank">effect of ventilation on a tuberculosis outbreak</a> at Taipei University. Many of the rooms in the school were underventilated and had CO2 levels above 3,000 ppm. When engineers improved air circulation and got CO2 levels under 600 ppm, <a href="https://doi.org/10.1111/ina.12639" target="_blank">the outbreak completely stopped</a>. According to the research, the increase in ventilation was responsible for 97% of the decrease in transmission.</p><p>Since the coronavirus is spread through the air, higher CO2 levels in a room likely mean there is a <a href="https://doi.org/10.1111/ina.12639" target="_blank">higher chance of transmission</a> if an infected person is inside. Based on the study above, I recommend trying to keep the CO2 levels below 600 ppm. You can buy <a href="https://doi.org/10.5194/amt-7-3325-2014" target="_blank">good CO2 meters</a> for around $100 online; just make sure that they are accurate to within 50 ppm.</p>
Air Cleaners<p>If you are in a room that can't get enough outside air for dilution, consider an air cleaner, also commonly called air purifiers. These machines remove particles from the air, usually using <a href="https://doi.org/10.1016/j.cap.2005.07.013" target="_blank">a filter</a> made of tightly woven fibers. They can <a href="https://shellym80304.files.wordpress.com/2020/06/miller-leiden-et-al-1996.pdf" target="_blank">capture particles containing bacteria and viruses</a> and can help reduce disease transmission.</p><p>The U.S. Environmental Protection Agency says that <a href="https://www.epa.gov/coronavirus/air-cleaners-hvac-filters-and-coronavirus-covid-19" target="_blank">air cleaners can do this for the coronavirus</a>, but not all air cleaners are equal. Before you go out and buy one, there are few things to keep in mind.</p><p>The first thing to consider is <a href="https://shellym80304.files.wordpress.com/2020/06/air-cleaner-report.pdf" target="_blank">how effective an air cleaner's filter is</a>. Your best option is a cleaner that uses a high-efficiency particulate air (<a href="https://doi.org/10.1016/S0021-8502(05)80214-9" target="_blank">HEPA</a>) filter, as these remove more than <a href="https://doi.org/10.1063/1.2771421" target="_blank">99.97% of all particle sizes</a>.</p><p>The second thing to consider is how powerful the cleaner is. The bigger the room – or the more people in it – the more air needs to be cleaned. I worked with some colleagues at Harvard to put together a tool to help teachers and schools determine <a href="https://docs.google.com/spreadsheets/d/1NEhk1IEdbEi_b3wa6gI_zNs8uBJjlSS-86d4b7bW098/edit#gid=1275403500" target="_blank">how powerful of an air cleaner you need for different classroom sizes</a>.</p><p>The last thing to consider is the validity of the claims made by the company producing the air cleaner.</p><p>The Association of Home Appliance Manufacturers certifies air cleaners, so the AHAM Verifide seal is a good place to start. Additionally, the California Air Resources Board has a <a href="https://ww2.arb.ca.gov/our-work/programs/air-cleaners-ozone-products/california-certified-air-cleaning-devices" target="_blank">list of air cleaners</a> that are certified as safe and effective, though not all of them use HEPA filters.</p>
Keep Air Fresh or Get Outside<p>Both the <a href="https://www.who.int/news-room/commentaries/detail/transmission-of-sars-cov-2-implications-for-infection-prevention-precautions" target="_blank">World Health Organization</a> and <a href="https://www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/deciding-to-go-out.html" target="_blank">U.S. Centers for Disease Control and Prevention</a> say that poor ventilation increases the risk of transmitting the coronavirus.</p><p>If you are in control of your indoor environment, make sure you are getting enough fresh air from outside circulating into the building. A CO2 monitor can help give you a clue if there is enough ventilation, and if CO2 levels start going up, open some windows and <a href="https://www.advisory.com/daily-briefing/2020/07/17/outdoor-gathering" target="_blank">take a break outside</a>. If you can't get enough fresh air into a room, an air cleaner might be a good idea. If you do get an air cleaner, be aware that they don't remove CO2, so even though the air might be safer, CO2 levels could still be high in the room.</p><p>If you walk into a building and it feels hot, stuffy and crowded, chances are that there is not enough ventilation. Turn around and leave.</p><p>By paying attention to air circulation and filtration, improving them where you can and staying away from places where you can't, you can add another powerful tool to your anti-coronavirus toolkit.</p>
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The tiny island nation of Mauritius, known for its turquoise waters, vibrant corals and diverse ecosystem, is in the midst of an environmental catastrophe after a Japanese cargo ship struck a reef off the country's coast two weeks ago. That ship, which is still intact, has since leaked more than 1,000 metric tons of oil into the Indian Ocean. Now, a greater threat looms, as a growing crack in the ship's hull might cause the ship to split in two and release the rest of the ship's oil into the water, NPR reported.
On Friday, Prime Minister Pravind Jugnauth declared a state of environmental emergency.
France has sent a military aircraft carrying pollution control equipment from the nearby island of Reunion to help mitigate the disaster. Additionally, Japan has sent a six-member team to assist as well, the BBC reported.
The teams are working to pump out the remaining oil from the ship, which was believed to be carrying 4,000 metric tons of fuel.
"We are expecting the worst," Mauritian Wildlife Foundation manager Jean Hugues Gardenne said on Monday, The Weather Channel reported. "The ship is showing really big, big cracks. We believe it will break into two at any time, at the maximum within two days. So much oil remains in the ship, so the disaster could become much worse. It's important to remove as much oil as possible. Helicopters are taking out the fuel little by little, ton by ton."
Sunil Dowarkasing, a former strategist for Greenpeace International and former member of parliament in Mauritius, told CNN that the ship contains three oil tanks. The one that ruptured has stopped leaking oil, giving disaster crews time to use a tanker and salvage teams to remove oil from the other two tanks before the ship splits.
By the end of Tuesday, the crew had removed over 1,000 metric tons of oil from the ship, NPR reported, leaving about 1,800 metric tons of oil and diesel, according to the company that owns the ship. So far the frantic efforts are paying off. Earlier today, a local police chief told BBC that there were still 700 metric tons aboard the ship.
The oil spill has already killed marine animals and turned the turquoise water black. It's also threatening the long-term viability of the country's coral reefs, lagoons and shoreline, NBC News reported.
"We are starting to see dead fish. We are starting to see animals like crabs covered in oil, we are starting to see seabirds covered in oil, including some which could not be rescued," said Vikash Tatayah, conservation director at Mauritius Wildlife Foundation, according to The Weather Channel.
While the Mauritian authorities have asked residents to leave the clean-up to officials, locals have organized to help.
"People have realized that they need to take things into their hands. We are here to protect our fauna and flora," environmental activist Ashok Subron said in an AFP story.
Reuters reported that sugar cane leaves, plastic bottles and human hair donated by locals are being sewn into makeshift booms.
Human hair absorbs oil, but not water, so scientists have long suggested it as a material to contain oil spills, Gizmodo reported. Mauritians are currently collecting as much human hair as possible to contribute to the booms, which consist of tubes and nets that float on the water to trap the oil.
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Environmentalists and ornithologists found a friend in a federal court on Tuesday when a judge struck down a Trump administration attempt to allow polluters to kill birds without repercussions through rewriting the Migratory Treaty Bird Act (MBTA).
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By Elizabeth Claire Alberts
There are trillions of microplastics in the ocean — they bob on the surface, float through the water column, and accumulate in clusters on the seafloor. With plastic being so ubiquitous, it's inevitable that marine organisms, such as sharks, will ingest them.
Polyproylene fibers found in one of the sampled sharks. Kristian Parton
Spiny dogfish. NOAA / Wikimedia Commons<p>"There appear to be two routes for these particles to end up in the sharks," Parton said. "The first through their food source [such as] crustaceans. Their prey may already contain these fibers, and consequently it's passed to the shark through bioaccumulation up the food chain. The second pathway is direct ingestion from the sediment. As these sharks feed, they'll often suck up sediment into their mouths, some of this is expelled straight away, although some is swallowed, therefore fibers and particles that may have sunk down into the seabed may be directly ingested from the surrounding sediment as these sharks feed."</p><p>Some sharks only contained a few plastic particles, but others contained dozens. The larger the shark, the more plastic was in it, the findings suggested. The highest number of microplastics was found in an individual bull huss, which had 154 polypropylene fibers inside its stomach and intestines.</p><p>"It's perhaps likely this individual shark had swallowed a larger piece of fishing rope/netting and this has broken down during digestive processes within the shark, and also broken down into smaller pieces during our analysis," Parton said.</p>
Lesser-spotted dogfish caught as bycatch. Kristian Parton<p>While this study only examined the stomach and digestive tracts of demersal sharks, Parton says it's possible that plastic would be present in other parts of the sharks' bodies, such as the liver and muscle tissue. However, more research would be needed to prove this.</p><p>At the moment, there is also limited understanding of how microplastic ingestion would impact a shark's health, although microplastics are known to negatively influence feeding behavior, development, reproduction and life span of zooplankton and crustaceans.</p><p>"If we can show that these fibers contain inorganic pollutants attached to them, then that could have real consequences for these shark species at a cellular level, impacting various internal body systems," Parton said.</p>
Parton in the lab. Kristian Parton<p>This new study demonstrates how pervasive and destructive plastic pollution can be in the marine environment, according to Will McCallum, head of oceans for Greenpeace U.K.</p><p>"Our addiction to plastics combined with the lack of mechanisms to protect our oceans is suffocating marine life," McCallum said in a statement. "Sharks sit on top of the marine food web and play a vital role in ocean ecosystems. Yet, they are completely exposed to pollutants and other human impactful activities. We need to stop producing so much plastic and create a network of ocean sanctuaries to give wildlife space to recover. The ocean is not our dump, marine life deserves better than plastic."</p>
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By Loveday Wright and Stuart Braun
After a Japanese-owned oil tanker struck a reef off Mauritius on July 25, a prolonged period of inaction is threatening to become an ecological disaster.
<div id="bb0a7" class="rm-shortcode" data-rm-shortcode-id="e5aefc0fff61ab1aea2f4b03c5399864"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1291765757013983238" data-partner="rebelmouse"><div style="margin:1em 0">The #oilspill is devastating but I want to honour the community mobilisation at the Mahebourg waterfront today (to… https://t.co/UWFkZFdjdi</div> — Fabiola Monty (@Fabiola Monty)<a href="https://twitter.com/LFabiolaMonty/statuses/1291765757013983238">1596815930.0</a></blockquote></div><p>"Booms are made of nylon mesh filled with #sugarcane straws all hand-stitched by Mauritian volunteers, empty plastic bottles used as buoys," described Mauritian journalist Zeenat Hansrod in a tweet. </p>
How to Tackle Oil Spills<p>The method for tackling oil spills depends on several factors, including the type and amount of oil in question, location and weather conditions.</p><p>"Once the oil comes to shore, the more intensive the cleaning technique. You can risk causing further damage," said Nicky Cariglia, an independent consultant at Marittima, who specializes in marine pollution. </p><p>"If you wanted to remove all traces of oil, the techniques available become increasingly aggressive the less oil that remains. In mangroves, you would have the added risk of causing damage by trampling," Cariglia told DW. Highly sensitive mangrove ecosystems line the Mauritius east coast that is threatened by the current spill.</p><p>Because oil normally has a lower density than water, it floats on the surface of the ocean. This means that for clean-up action to be most effective, it should happen very quickly after a spill, before the oil disperses. </p>
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