Image: JOHN WESSELS (AFP)
This is reported by a research team with Austrian participation in the journal “Nature Sustainability”. If the temperature rises to 1.5 degrees Celsius, 14 percent would be affected. To date, 600 million people have been pushed out of the “human climatic niche” by climate change.
The research team led by Timothy Lenton from the University of Exeter (Great Britain) defined the temperature range in which most people lived in the past as a “human climatic niche”. For example, livestock can be kept there and useful plants can sprout. Caroline Zimm from the International Institute for Applied Systems Analysis (IIASA) in Laxenburg near Vienna was also involved in the study.
Different scenarios
Under different climate scenarios, the researchers examined how many people will live in regions with temperatures beyond this human climate niche by the next turn of the century. With the currently most likely temperature development (plus 2.7 degrees Celsius on a global average), this would be a third of the nine billion people who, according to forecasts, then inhabit the earth.
The chances of complying with the 1.5 degree limit are slim given the continued increase in greenhouse gas emissions. In fact, the Earth is currently heading for 2.7 degrees of warming, and this will fundamentally change the “habitability” of the Earth and potentially lead to “a large-scale reorganization of the places where people live,” said lead author Lenton.
India, Nigeria and Indonesia most at risk
For every additional 0.1 degree increase in temperature, “an additional 140 million people will be exposed to dangerous heat,” Lenton added. The countries with the largest number of people at risk of dangerous heat, according to the study, are India (600 million people), Nigeria (300 million people) and Indonesia (100 million people).
Conversely, if the trend were positive for every 0.3 degree Celsius temperature rise avoided, 350 million fewer people would be affected. If the Paris Agreement’s goal of limiting warming to 1.5 degrees Celsius were achieved, it would be “only” 14 percent. Living outside the “human climatic niche” would mean increased disease and mortality, they explain.
Dangerous heat: Average 29 degrees
The authors of the study define an average temperature of 29 degrees as dangerous heat. The risk is particularly great in the hot and humid regions along the equator: there, heat can be life-threatening even at low temperatures because the body cannot cool down by evaporating sweat on the skin when the humidity is high.
Source: Nachrichten
