Europe and the Arctic are warming fastest, but there are many more people in parts of the Middle East, India, and East Asia that may also warm faster than the rest of the globe.
As the planet grows warmer because of climate change, it will not happen evenly. So far, as the physics of Earth’s climate systems would predict, we’re seeing the most warming near the poles (1). But as MIT professor of environmental engineering Elfatih Eltahir explains, some of the most worrying regions for future warming are also among the most populated on our planet.
As Eltahir points out, climate records have already shown some countries heating up faster than others, including the polar regions of Russia and Canada (2). Warming in these Arctic regions leads to the loss of ice and snow, which are highly reflective and bounce a lot of sunlight back into space. Once they are gone, there is more exposed land to absorb the sun’s energy.
Current data also shows temperatures rising faster in the Sahara Desert, as well as in a large piece of South America that falls mostly within Brazil (2). The causes are not entirely clear, but Eltahir says land use changes, especially deforestation, may play an outsized role in the region’s warming trend. (There is also a persistent spot in the North Atlantic Ocean that is cooling while the rest of the globe warms, driven by atmospheric changes(3)).
Another outlier? Europe, which has warmed more than twice as fast as the world as a whole over the past 30 years (4). This is partly because much of Europe lies within the Arctic, but even European countries in the mid-latitudes have seen fast-rising temperatures and extraordinary heatwaves. The causes are still debated, but one reason may be that the Mediterranean is getting drier: with less moisture in the soil, the air above can’t cool as much through evaporation (5).
Eltahir’s research also uses climate models to project future temperatures under a variety of scenarios. What worries him the most is the region of southern Asia that stretches from the Persian Gulf through the Indus and Ganges river deltas in India, all the way to the North China Plain (6, 7). In all the scenarios he models, this belt heats up faster than nearly anywhere else on Earth, with low-lying coastal areas and river valleys hit hardest.
The trend is concerning on several fronts. Although a warming Arctic could have severe consequences for the Earth’s overall climate system, few people live in these regions. The section of Asia that Eltahir has identified is home to more than a billion people.
Besides, it’s not just heat: his research also predicts these areas will experience more humidity, and heat plus humidity leads to very dangerous conditions for human health (8). Eltahir’s studies project a growing trend of humid heatwaves (9), and though some are predicted for regions such as the American Midwest, the highest concentration by far would be across the South Asian belt. Wealthier citizens from Persian Gulf nations like Qatar and the United Arab Emirates may be able to withstand these heatwaves by seeking shelter inside air-conditioned buildings. In Northern India, where people are more likely to be poorer farm workers, that may not be true.
“You have weather that's coming from climate change concentrated in an area where the population is most vulnerable in terms of not only their level of income, but also in terms of their numbers and [activities]—they work as farmers in the field,” he says.
Thank you to Kiku Benjamin of Uganda for the question. You can submit your own question to Ask MIT Climate here.
Published March 21, 2023.
FOOTNOTES
1 For a more detailed explanation, see our previous edition of Ask MIT Climate, "Which parts of the planet are warming the fastest, and why?"
2 NASA Global Climate Change: Vital Signs of the Planet—Temperature.
3 National Oceanic and Atmospheric Administration, Climate Program Office. "Models show North Atlantic cooling driven by atmospheric processes." October 7, 2022.
4 World Meteorological Organization: "State of the Climate in Europe 2021."
5 MIT News: "3 Questions: Why Europe is so vulnerable to heat waves," David L. Chandler, October 11, 2022.
6 Pal, Jeremy, and Elfatih Eltahir. "Future temperature in southwest Asia projected to exceed a threshold for human adaptability." Nature Climate Change, Vol. 6, 2016, doi:10.1038/nclimate2833.
7 Kang, Suchul, and Elfatih Eltahir. "North China Plain threatened by deadly heatwaves due to climate change and irrigation." Nature Communications, Vol. 9, 2018, doi:10.1038/s41467-018-05252-y.
8 Im, Eun-Soon, Jeremy Pal, and Elfatih Eltahir. "Deadly heat waves projected in the densely populated agricultural regions of South Asia." Science Advances, Vol. 3, Issue 8, 2017, doi:10.1126/sciadv.1603322.
9 National Weather Service: What is the heat index?