The damage caused by the climate crisis cost an estimated $16m an hour over the last 20 years.
Storms, floods, heatwaves and droughts have taken many lives and destroyed huge amounts of property, with the warming planet making the events more frequent and intense.
The study, published in the journal Nature Communications, is the first to calculate a global figure for the increased costs directly attributable to human-caused global heating.
It found average costs of $140bn a year from 2000 to 2019, although the figure varies from year to year from a low of $60bn, with the latest data showing $280bn in costs in 2022.
The years with the highest overall climate crisis costs were 2003, when a heatwave struck Europe, 2008, when Cyclone Nargis hit Myanmar, and 2010, when drought hit Somalia and a heatwave hit Russia. Property damages were higher in 2005 and 2017 when hurricanes hit the US, where property values are high.
The analysis used a statistical value of a death of $7m, an average of the figures used by the US and UK governments.
The researchers said lack of data, particularly in low-income countries, meant the figures were likely to be seriously underestimated, and additional climate crisis costs, such as from crop yield declines and sea level rise, were also not included.
The study also found that the number of people affected by extreme weather because of the climate crisis was 1.2 billion over two decades.
The Climate Crisis Cost Breakdown
Two-thirds of the damage costs were due to the lives lost, while a third was due to property and other assets being destroyed. Storms, such as Hurricane Harvey and Cyclone Nargis, were responsible for two-thirds of the climate costs, with 16 per cent from heatwaves and 10 per cent from floods and droughts.
The researchers said their methods could be used to calculate how much funding was needed for a loss and damage fund established at the UN’s climate summit in 2022, which is intended to pay for the recovery from extreme weather disasters in poorer countries.
‘The headline number is $140bn a year and, first of all, that’s already a big number,’ said Prof Ilan Noy, at the Victoria University of Wellington in New Zealand, who carried out the study with colleague Rebecca Newman. ‘Second, when you compare it to the standard quantification of the cost of climate change, it seems those quantifications are underestimating the impact of climate change.
‘A lot of people are very uncomfortable with the idea that we put a price tag on a life. But this is very standard economic practice and comes about because, ultimately, we need make decisions about [the value of] investments in various things.’