The Press and Journal (Inverness, Highlands, and Islands)
Heat threatens life of billions
Current climate policies will leave more than a fifth of humanity exposed to dangerously hot temperatures by 2100, unprecedented new research suggests.
The paper, published yesterday and co-authored by academics from around the world, examines the “human climate niche” – the temperature range in which humans have lived and flourished throughout history – and how warming could see billions of people falling outside of it.
The researchers from the University of Exeter’s Global Systems Institute, alongside the Earth Commission and Nanjing University, argue that current legally binding climate policies are estimated to produce an average temperature rise of 2.7C by 2100.
They said this could leave two billion people – 22% of the projected end-ofcentury population – exposed to dangerous heat, defined as an average annual temperature of 29°C or higher.
At these high temperatures, water resources could become strained, mortality could increase, economic productivity could decrease, animals and crops could no longer flourish, and large numbers of people may migrate.
The forecasts also show that limiting warming to 1.5C in line with the Paris Climate Agreement would leave just 5% outside the niche by 2100.
Professor Tim Lenton, director of the Global Systems Institute, said that many areas of the world will “go up to unprecedented temperatures that nobody experienced in the historical climate” when warming hits 2.7C.
More than 600 million people in India and 300 million people in Nigeria could be exposed to dangerous temperatures by 2100, as well as areas of Indonesia, Brazil, the Philippines, Australia, and almost 100% of Burkina Faso and Mali.
The research found that under the worst-case scenarios of 3.6C or even 4.4C global warming, half of the world’s population could be left outside the climate niche, posing an “existential risk”.
Prof Lenton said: “The costs of global warming are often expressed in financial terms, but our study highlights the phenomenal human cost of failing to tackle the climate emergency.”