One of the major successes of the 21st century has been the reduction in global inequality. But the wealth gap between countries could have closed even further if not for climate change.
Over the past few decades, global warming has led to “robust and substantial declines in economic output in hotter, poorer countries,” according to in a study published yesterday in the peer-reviewed journal, Proceedings of the National Academy of Sciences, and increases in cooler, wealthier countries compared to what would have happened in a world without human-caused climate change. “The global warming caused by fossil fuel use has likely exacerbated the economic inequality associated with historical disparities in energy consumption,” write the authors, Noah Diffenbaugh and Marshall Burke, both of Stanford University.
Building on previous research into the links between economic growth and temperature change, the researchers quantified the unequal economic impact of climate change over half a century. They show the extent to which global warming has made poor countries poorer and rich countries richer.
Between 1961 and 2010, the gap in per capita income between the richest 10% and poorest 10% of countries (accounting for population size), was 25% larger than it would have been without global warming, the researchers found. Diffenbaugh and Burke said that poorer countries had both missed out on some of the direct benefits of fossil-fuel use and were being “significantly harmed” by the global warming created by the energy consumption of wealthier countries.
Over that half century, the median economic losses in countries closer to the equator—including parts of South America, central Africa, and South East Asia—were 25% greater than they would have been in a world without global warming, the paper shows. For example, the negative economic impact, measured in per capita GDP, was 31% for India, 29% for Nigeria, and 25% for Brazil. The countries that have become richer due to global warming include Canada, which experienced a 32% increase in per capita GDP and Norway with a 34% increase, relative to a world without climate change. Some other countries, including China and US, registered very little change in GDP due to climate change over the half century.
All 18 countries whose cumulative per capita carbon-dioxide emissions from 1961 to 2010 were less than 10 tons experienced negative economic impacts from climate change, with a median decline of 27% in per capita GDP. Similarly, all 36 countries whose carbon dioxide emissions were between 10 and 100 tons per capita had a negative economic impacts, the median losses being 24%.
In comparison, 14 of the 19 countries whose per capita cumulative emissions exceeded 300 tons experienced an economic benefit, with a median gain of 13% in per capita GDP. “In addition to the direct benefits of fossil fuel use, many wealthy countries have likely been made even more wealthy by the resulting global warming,” Diffenbaugh and Burke concluded.