Breaching climate tipping points could triple economic cost of environmental crisis, scientists warn

Losses would be incurred ‘everywhere in the world’ in event of such significant climate collapse

Exceeding critical “tipping points” in the climate system could lead to significant increases in the economic impacts of the global environmental crisis, discomforting new research has warned.

A research team led by academics at the Grantham institute at LSE used new models to estimate the economic fallout from major climate tipping points being breached, such as the disintegration of the Greenland ice sheet, the thawing of permafrost and dieback of the Amazon rainforest.

The research revealed that should any of these tipping points come to pass, their resultant impact would likely increase the economic cost of damages from the climate crisis by about 25 per cent compared to previous projections.

However, the authors suggested that the main scenario they modelled “could be conservative”, and that the tipping points could in fact trigger much greater damages.

Their study found that there is a 10 per cent chance of the tipping points at least doubling the costs of climate change impacts, and a 5 per cent chance of them tripling costs.

The authors examined eight tipping points that have been described in the scientific literature:

• Thawing of permafrost, leading to carbon feedback resulting in additional carbon dioxide and methane emissions, which flow back into the carbon dioxide and methane cycles.
• Dissociation of ocean methane hydrates, resulting in additional methane emissions, which flow back into the methane cycle.
• Arctic sea ice loss (also known as ‘the surface albedo feedback’), resulting in changes in radiative forcing, which directly affects warming.
• Dieback of the Amazon rainforest, releasing carbon dioxide, which flows back into the carbon dioxide cycle.
• Disintegration of the Greenland Ice Sheet, increasing sea-level rise.
• Disintegration of the West Antarctic Ice Sheet, increasing sea-level rise.
• Slowdown of the Atlantic Meridional Overturning Circulation, modulating the relationship between global mean surface temperature and national mean surface temperature.
• Variability of the Indian summer monsoon, directly affecting GDP per capita in India.

The study found that economic losses associated with the tipping points would occur almost everywhere in the world.

The dissociation of ocean methane hydrates and thawing permafrost would create the largest economic impacts.

The model includes national-level climate damages from rising temperatures and sea levels for 180 countries.

The authors emphasised that their calculation of the impacts are likely to be underestimates, but said their model can be updated as more information about tipping points is discovered.

Professor Simon Dietz from the Grantham Institute at LSE said: “Climate scientists have long emphasised the importance of climate tipping points like thawing permafrost, ice sheet disintegration, and changes in atmospheric circulation.

“Yet, save for a few fragmented studies, climate economics has either ignored them, or represented them in highly stylised ways. We provide unified estimates of the economic impacts of all eight climate tipping points covered in the economic literature so far.”

The research is published in the journal Proceedings of the National Academy of Sciences.