The melting of the Earth’s permafrost could unleash hundreds of billions of tons stored CO2 and methane by the end of this century, warned prominent researchers on Monday, with resulting economic costs that could reach $43 trillion in damages related to the runaway impacts of climate change.

In a paper published in the journal Nature Climate Change, Prof. Chris Hope of Cambridge University and Prof. Kevin Schaefer, from the National Snow and Ice Data Center at the University of Colorado, say their study shows that because the “Arctic is warming roughly twice as fast as the global average” and if current trends continue, the melting of huge sections of permafrost in the coming decades could result in hundreds of billions of ton of carbon dioxide (CO₂₎ and billions of tons of methane (CH₄₎ being released into the atmosphere.

Such an enormous increase of greenhouse gases would result in both economic and non-economic impacts, the researchers said. Computer models run by Hope and Schaefer found that melting permafrost would lead to higher chances of catastrophic and cascading events, such as the melting of the Greenland and West Antarctic ice sheets which would lead to increased flooding and more extreme weather around the world. Economic impacts cited included direct influence on the gross domestic product (GDP) of countries—such as the loss of agricultural output and the additional cost of coping with floods and heatwaves—while non-economic impacts included negative effects on human health and natural ecosystems.

The extra impacts that could be created by the melting permafrost, the researchers found, are “sufficiently high to justify urgent action” on the part of policy-makers and government leaders.

“These results show just how much we need urgent action to slow the melting of the permafrost in order to minimize the scale of the release of greenhouse gases,” said co-author Dr Chris Hope from the Cambridge Judge Business School.