Fifty years of rising global temperatures have significantly impoverished equatorial countries like India and Nigeria, producing economic losses on the scale of that North America faced during the Great Depression, while wealthy northern nations like Canada and Norway have thrived in the early stages of the climate crisis, says a study published last week in the Proceedings of the National Academy of Sciences.
Stanford climate scientist Noah Diffenbaugh, together with Earth system scientist colleague Marshall Burke, “combed through 50 years of annual temperature readings and measurements of gross domestic product (GDP) for 165 nations, to tease out the effects of temperature fluctuation on economic growth,” reports Climate News Network.
“Our results show that most of the poorest countries on Earth are considerably poorer than they would have been without global warming,” Diffenbaugh said, while “the majority of rich countries are richer than they would have been.”
What Diffenbaugh and Burke found is that “during warmer-than-average years, [economic] growth was accelerated in those nations with normally cool climates—such as Norway and Sweden—but was slowed significantly in those countries with tropical or subtropical climates such as India or Nigeria,” Climate News notes. Diffenbaugh added that India “has approximately 30% lower per capita GDP today than if global warming had not occurred,” a magnitude of decline comparable to the impacts of the Great Depression on the United States.
“The historical data clearly show that crops are more productive, people are healthier, and we are more productive at work when temperatures are neither too hot nor too cold,” Burke explained. Which means that, while in colder climates “a little bit of warming can help, the opposite is true in places that are already hot.”
He noted that “some of the larger economies are close to the perfect temperature for economic production. Global warming has not pushed them from the top of the hill and, in many cases, has pushed them towards it, but a large amount of warming in the future will push them further and further away from the optimum temperature.”
The Stanford scientists conceded that their use of a counter-factual comparison—against what would have happened if global average temperatures had not risen by around 1.0°C in the last century—produces a degree of uncertainty. But they said their findings are in keeping with those observed by others on the ground. “Geographers, economists, and climate scientists have repeatedly pointed out that global warming consistently threatens the poorest people in any society,” Climate News Network notes.
And while the authors of the Stanford study have spent a good deal of time looking back into the recent past to provide what Diffenbaugh calls “the first accounting of exactly how much each country has been impacted economically by global warming, relative to historical greenhouse gas emissions,” their conclusions point forward.
“Historically, rapid economic development has been powered by fossil fuels,” he said. “Our finding that global warming has exacerbated economic inequality suggests that there is an added economic benefit of energy sources that don’t contribute to further warming.”