Underlying the link is the impact that rising temperatures have on people’s ability to work, their health and even their ability to think, as well as harm to crops and machinery. Today, the US, Japan and China have average annual temperatures close to the sweet spot of 13C, meaning that further warming will begin to harm their economies.
But Brazil, India, Indonesia and Nigeria are already much warmer, meaning the impact of climate change on their economic growth will be even greater. The UK and Germany are currently cooler than 13C, meaning their economies may improve a little as temperatures rise, before starting to decline.
...The new analysis, published in the journal Nature on Wednesday, began by examining the economic performance of countries between 1960 and 2010. When a country’s average temperature was above 13C, they found that national economies performed worse in warmer years than in cooler years. Below 13C, the reverse was the case.
“This relationship we have uncovered is almost like a law,” said Solomon Hsiang, at the University of California, Berkeley, a member of the research team. “Over the last 50 years, this relationship between how temperature fluctuates and how economies perform hasn’t changed a bit.”
“So it shouldn’t be too surprising that it is going to reshape the global economy in ways that are going to be quite traumatic. We can then ask whether or not we want to subject future generations to that turmoil and change, or if we want to invest what seems like a relatively small amount of today to avoid that scenario.”
Climate economist Lord Nicholas Stern, at the London School of Economics, said: “This paper recognises that climate change could have impacts that increase very steeply with rising global average temperature. This is an advance on other previous studies [which have] made severe underestimates of the economic effects of unmanaged climate change.”
But he said even the new estimate could be unduly lower, because many possible and severe disruptions suggested by scientific evidence had not been included.