India and Pakistan have recently faced temperatures around 50°C during many days. While the real impact on mortality has not yet been communicated, the Indian health services have already estimated that the number of people killed by the heat in India since 1967 is at least 40,000. This figure is probably greatly underestimated given India’s difficulty in obtaining data on the health of its poorest and most isolated population. Closer to home, the heat wave benchmark in Europe, that of summer 2003, had been responsible for the death of at least 70,000 people (including 15,000 in France) in the space of a month and a half. In 2010, the heat wave in Russia caused the death of at least 10,000 people in Moscow.
48-74% of population at risk of fatal heat by 2100
The human body cannot function normally with an internal temperature above approximately 37°C, yet waves heat, especially when combined with humidity, can increase the body temperature far above. The conclusions of the University of Hawaii, published in the review Nature Climate Change, tend towards a particularly dark scenario for humanity. Three quarters of the world’s population could die of heat within 80 years if the climate continues to heat up at the same speed. If humanity decided in the meantime to reduce its emissions of greenhouse gas drastically, this alarming figure would then drop to 48% according to the researchers’ estimates. Currently, the university estimates that 30% of the population is exposed to at least 20 days of life-threatening heat per year. ” When it comes to heat waves, we have a choice between a bad future scenario, or a terrible one” according to the study’s lead author, Camilo Mora.
New York and London will also see their hot days explode
The areas with a tropical climate will be most at riskbecause the humid heat is present there all year round, unlike the zones located further north where these conditions weather report are only present in summer. Plus, the temperature is already naturally high in the tropics, so all it takes is a simple slight rise to bring the heat to a deadly threshold.
While heat waves are obviously much more deadly in countries that do not benefit enough from access toair conditioning, they also kill in large modern cities. Among the major cities that have experienced a high death rate during the last heat waves, we find, for example, New York, Washington, Los Angeles, Chicago, Toronto, London, Beijing, Tokyo, Sydney and São Paulo. Although located in the northern United States, New York City could experience 50 life-threatening heat days per year by 2100. This number of high-risk days for human health will rise to 30 per year for Los Angeles and 20 per year for Sydney in Australia. For American cities that already benefit from a hot and humid climate, such as Orlando in Florida and Houston in Texas, the number of days of deadly heat by 2100 could exceed 90, that is to say the whole summer!
In the city, as in the countryside, the heat is devastating
The most isolated populations are those with the fewest air conditioner (which also contributes to emissions of greenhouse gas), and access to care. But in big cities, like Paris or New York, the urban heat island phenomenon wreaks havoc. During the 2003 heat wave in Europe, elderly women, sedentary and alone, were the first victims. Just behind, men aged 25 to 64, due to the fact that the majority of them work outdoors. In addition to the direct effects of heat on the risk of mortality, indirect consequences increase the health risks: virus development and vector-borne diseases (related to mosquitoes particular) in hot and humid areas, but also the risks linked to the dangerous mixture of heat and pollution in theozone. Faced with these threats, there is only one solution, to historically reduce our greenhouse gas emissions. A change that has not yet been initiated since CO emissions2 and methane have again reached a record level in 2021.
Global warming: mortality will increase by more than 40% if we exceed this threshold
Article of Nathalie Mayerpublished on March 12, 2022
While the latest report published by the Intergovernmental Panel on Climate Change (IPCC) focuses on the impacts of global warming on the planet and on populations, researchers are now telling us that warming above 2°C would put us at an increased risk of dying from heat.
Since pre-industrial times, the Earth has warmed by about 1.1°C. In question, it is still necessary to recall it, our emissions of greenhouse gas. For the time being, thanks in particular to milder winters, the overall temperature-related mortality seems to be decreasing slightly. But researchers of theUniversity College London (UCL, UK) report today that this mortality will increase dramatically if global warming were to exceed 2°C.
The researchers’ work examines the impact of climate change on the number of deaths directly related to temperature. All for England and the Country of Wales. Considering just as much the risks associated with hot weather in summer and cold weather in winter. Their conclusion: During the hottest days of the year, mortality will increase by as much as 42% compared to pre-industrial levels.
The researchers note that as the global average temperature increases, summer temperature-related mortality will increase at a rapid and non-linear rate. With an acceleration and a much higher risk once the warming reaches 2.5°C. At +3°C, the increase in mortality could reach 75%.
A real advantage in limiting global warming
In winter, the mortality rate seems to want to continue to decrease. But the result should be taken with caution. Because it does not take into account deaths linked to extreme weather events which may, in the context of global warming, occur more frequently and more markedly, especially during this season.
Until today, most temperature-related deaths in England and Wales — 9% of deaths in 2021 — are still due to cold temperatures. A figure that researchers expect to see further decline. In a completely linear way with the continuation of climate change.
But in the future, if warming exceeds 2°C, it will not only be hot days which will be to be feared, but also the days during which the summer temperatures will be at an average level. Thus the consequences of 2°C of warming will be much greater than what researchers had imagined in the past. A new way, after the recent publication of the report of the Intergovernmental Panel on Climate Change (IPCC) devoted precisely to the impacts of climate change on our lives, to show how important it is to limit global warming. Because it could have substantial benefits on our health.
Are you going to die from global warming?
More than a third of deaths, in which high heat is involved between 1991 and 2018, are attributable to global warming caused by anthropogenic activities, according to a study published in Nature Climate Change.
Article of Mary Origas published 25/06/2021
Global warming, due to anthropogenic activities, has a considerable impact on the planet and, consequently, on human health. Heat waves affect vulnerable, elderly, but also the youngbecause high temperatures increase, among other things, the ozone concentration, which can damage lung tissue; they also lead to losses in agricultural productivity due to droughtsweakening the Food Safety ; excessive heat promotes the spread of infectious diseases, also called zoonoses ; they destabilize the whole world. Thus, according to the World Health Organization (WHO), this climate change is responsible for at least 150,000 deaths per year, a figure that is expected to double by 2030.
Extreme weather events kill thousands, study finds Global Climate Risk Index 2018 from think tank Germanwatch
For now, the scenarios of future climate conditions predict a substantial increase in average temperatures, with extreme events. This may accentuate the pressure health and increase the number of deaths. A study published in Nature Climate Change and led by a team of London School of Hygiene & Tropical Medicine (LSHTM) and the University of Bern within the multi-city, multi-country (MCC) collaborative research network, wanted to determine to what extent the impacts of global warming have already occurred in the past decades until today. today, focusing on the heat-related mortality and morbidity. The results are worrying.
Global warming : “37% of heat-related deaths”
“Each continent is already suffering the disastrous consequences of human activities on our planet”, explains Professor Antonio Gasparrini (LSHTM), lead author of the study. Using data from 732 sites in 43 countries around the world, he and his team estimate that, overall, 37% of deaths related to heatin recent summer periods, were attributable to global warming. This percentage was highest in Central and South America (up to 76% in Ecuador or Colombia, for example) and in Southeast Asia (between 48 and 61%). It should be noted that the inhabitants of low-income or middle-income countries are the most affected, while these states are only responsible for a small part of anthropogenic emissions in the past.
The estimates also show the number of annual deaths due to human-induced climate change occurring specifically in certain cities: 136 additional deaths per year in Santiago, Chile (44.3% of the total heat-related deaths in the city), 189 in Athens (26.1%), 172 in Rome (32%), 156 in Tokyo (35.6%), 177 in Madrid (31.9%), 146 in Bangkok (53.4%), 82 in London (33.6%), 141 to New York (44.2%) and 137 in Ho Chi Minh City (48.5%). Dr Ana M. Vicedo-Cabrera from the University of Bern said: “We expect the proportion of heat-related deaths to continue to rise if we do nothing to combat climate change or adapt. »
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