People walk on the Dune du Pilat near La Teste-de-Buch in southwestern France during a destructive heat wave that prompted forest fires and mass evacuations on July 16, 2022 GAIZKA IROZ/AFP via Getty Images
Founded in 2005 as an Ohio-based environmental journal, EcoWatch is a digital platform dedicated to publishing quality scientific content about environmental problems, causes and solutions.
For hundreds, if not thousands of years, humans have lived in a relatively comfortable environment”climate niche” in which a large part of the world’s population has mainly benefited from temperatures and infrequent extreme weather conditions events. Conditions that were not only within a healthy temperature range for humans, but for the plants, animals And ecosystems of our planet.
A new study estimates that billions of people will be driven out of this climatic niche by global warming, where they will be vulnerable to more severe and frequent extreme weather and unprecedented high temperatures.
Today, nine percent of the world’s population – 600 million people – have already been pushed out of the niche by climate change.
“By the end of the century (2080-2100), current policies leading to global warming of around 2.7°C could leave a third (22-39%) of people out of the niche,” they said. writes the authors of the study.
The researchers added that limiting global warming to 1.5 degrees Celsius, or 2.7 degrees Fahrenheit – a level that many scientists now believe is unattainable due to the trajectory we are on due to human activities – would result in approximately five times fewer people exposed to the most extreme. temperatures.
The study, “Quantifying the human cost of global warming”, was published in the journal Natural durability.
The authors said that at the end of this century, the lifespan carbon the emissions of about 3.5 people on average across the world – or about 1.2 US citizens on average – will cause a future human being to be exposed to temperatures never seen before. And not just anyone, but someone who lives in a part of the world where current emissions are about 50% of the average for the rest of the planet. This demonstrates the need for policy changes to mitigate the consequences of climate change disparities for humanity as a whole, the authors wrote.
“The costs of global warming are often expressed in financial terms, but our study highlights the phenomenal human cost of not addressing the climate emergency,” said the professor. Tim Leton, director of the Global Systems Institute and chair of climate change and earth system science at the University of Exeter in the UK, who was also the lead author of the study, as reported by The Guardian. “Economic estimates almost always value the rich more than the poor because they have more assets to lose, and they tend to value those living today over those who will live in the future. We consider all people to be equal in this study.
If humans were able to limit global warming to 2.7 degrees Fahrenheit, 80% fewer people – or 400 million – would be forced out of the climate niche, reported The Guardian.
“For every 0.1°C of warming above current levels, an estimated 140 million additional people will be exposed to dangerous heat. This reveals both the scale of the problem and the importance of decisive action to reduce carbon emissions. Limitation global warming 1.5°C instead of 2.7°C would mean five times fewer people in 2100 exposed to dangerous heat,” Lenton said, according to Earth.com.
In countries that already experience extreme temperatures and have large numbers of people, most of the population will be forced out of the climatic niche. Nigeria and India will be the most affected countries, with Pakistan, the Philippines and Indonesia also suffering severe impacts.
“Such high temperatures (outside the niche) have been linked to issues such as increased mortality, decreased work productivity, decreased cognitive performance, impaired learning, unfavorable effects of pregnancy, the decrease crop yieldincreased conflict and the spread of infectious diseases,” said Professor Chi Xu from the School of Life Sciences at China’s Nanjing University, who was also part of the research team, as the reported The Guardian.
The study found that most humans live in parts of the globe with average annual temperatures of around 55.4 to 77 degrees Fahrenheit. Conditions hotter or colder than that are too extreme.
“Most of these people lived near the cooler 13°C peak of the niche and are now in the ‘middle ground’ between the two peaks. Although not dangerously hot, these conditions tend to be much drier and have not historically supported dense human populations,” Xu said, as reported by Earth.com.
If the planet continues to warm, the population increase combined with rising temperatures would lead to 3.7 billion people living outside the climate niche by 2090.
“The climatic niche describes where people thrive and have prospered for centuries, even millennia in the past. When people are on the outside (of the niche), they don’t thrive,” Lenton said, as reported by The Guardian.
In the extreme scenario in which the climate were to rise by 6.48 degrees Fahrenheit, nearly half of Earth’s population would be pushed out of the vital niche.
Lenton said the quickest and most realistic way for humans to adapt to more extreme temperatures is to increase the number of urban dwellers. green spaces.
“It can reduce extreme temperatures by 5C and provide shade – that’s huge,” Lenton said, according to The Guardian.