Climate change’s biggest losers

MCGILL U. (CAN) — Climate change in 50 years is expected to have the greatest impact on populations least responsible for causing the problem.

A new study finds that if populations continue to increase at the expected rate, people living in low-latitude, hot regions of the world, like central South America, the Arabian Peninsula and much of Africa, will be the most vulnerable to climate change.

Researchers already study how various species of plants and animals migrate in response to climate change.

Combining climate change data with census information, researchers are now able to use the same analytic tools to measure the impact of climate change on human populations.

Details are published in the journal Global Ecology and Biogeography.

A relatively small increase in temperature will have serious consequences on a region’s ability to sustain a growing population, says Jason Samson, a PhD candidate in natural resource sciences at McGill University.

“It makes sense that the low latitude tropical regions should be more vulnerable because the people there already experience extremely hot conditions which make agriculture challenging. An increase in temperature over the next few decades will only make their lives more difficult in a variety of ways.”

The findings contrast with predictions about the impact of climate change on human populations in the high-latitude more temperate zones of the world, where the temperature change is expected to be greater.

Because the spread of human populations and activities are already more constrained by the cooler conditions in these regions, climate change is expected to have less of an impact on people living in these areas.

There are clear inequities in the causes and consequences of climate change, Sampson says: the countries that have contributed the least to climate change, based on their average per-capita carbon dioxide emissions, are nevertheless predicted to be the most vulnerable to its impacts.

“Take Somalia for instance. Because it’s so hot there, it’s already very difficult to grow things, and it will only become more difficult if the temperature rises. It’s also clear that Somalia is not a big contributor of greenhouse gas to the atmosphere.

“Now thanks to this map, we have concrete quantitative evidence of the disparity between the causes and the consequences of climate change at a national level.”

The research was funded by the Natural Sciences and Engineering Council of Canada.

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