Global warming has increased global economic inequality. Some countries have profited from climate change while the same rise in average planetary temperatures has dragged down economic growth in the warmer countries.
The gap between those groups of nations with the highest and lowest economic output per person is now around 25% larger than it would have been had there been no climate change.
“Our results show that most of the poorest countries on Earth are considerably poorer than they would have been without global warming,” said Noah Diffenbaugh, a climate scientist at Stanford University in California. “At the same time the majority of rich countries are richer than they would have been.”
He and his co-author, Marshall Burke, an earth system scientist at Stanford, report in the Proceedings of the National Academy of Sciences that they 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.
They found that during warmer than average years 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.
And between 1961 and 2010, they found that global warming depressed the wealth per person in the poorest nations by between 17% and 30%.
“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,” said Burke. “This means that in cold countries, a little bit of warming can help. The opposite is true in places that are already hot.”
The two scientists put the message of climate injustice bluntly in their paper: “Our results show that, in addition to not sharing equally in the direct benefits of fossil fuel use, many poor countries have been significantly harmed by the warming arising from wealthy countries’ energy consumption.”
What if … ?
All such research is tortured by uncertainties, and none greater than what historians call counter-factual comparison: that is, what would have happened if global average temperatures had not risen by around 1 °C in the last century.
To make their case, the researchers calculated 20,000 versions of what each separate country’s economic growth rate would have been without global warming, and based their estimates on the range of outcomes. So, they concede, there are uncertainties.
But their findings are in line with other separate studies. Geographers, economists and climate scientists have repeatedly pointed out that global warming consistently threatens the poorest people in any society and that economic inequalities tend to stoke conflict and drive migration while at the same time economic inequalities continue to ensure that the poorest will suffer even more.
And national studies of specific climate events have confirmed the link between temperature and output. Burke has in an earlier study separately made the connection between rising temperatures and social conflict, and the Stanford two have already argued that even a small reduction in global warming would return huge economic benefits.
In effect, the latest research provides a kind of national climate audit. If greenhouse emissions are a measure of economic output, then the richest 10% produce atmospheric carbon dioxide almost as much as the bottom 90% together.
The Stanford study offers an estimate of the costs and benefits the richest and poorest have borne as a consequence of emissions. It also makes it clear that the poorer nations would benefit more from investment in renewable energy: that is, they could create more wealth in ways that did not intensify costly climate change.
“Our study makes the first accounting of exactly how much each country has been impacted economically by global warming, relative to historical greenhouse gas emissions,” said Diffenbaugh.
“Historically, rapid economic development has been powered by fossil fuels. 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.”
- This article first appeared at Climate News Network