The melting permafrost in the Arctic releasing greenhouse gases, methane and carbon dioxide will speed up global warming adding around $70tn (£54tn) to the world’s climate balance sheet, the most advanced study made so far concerning the economic consequences of thawing permafrost in the Arctic disclosed.
According to the paper published in Nature Communications on Tuesday, countries failed to meet their Paris Agreement 2015 commitments will cause nearly 5% amplification of global warming and its associated costs as a result of the feedback mechanism in combination with the loss of heat-deflecting white ice.
In the study, authors for the first time attempted to calculate the economic impact of permafrost melt and reduced albedo which is a measure of how much light that hits a surface gets reflected without being absorbed. It is based on the state-of-the-art computer models used for predicting the impact of temperature rise in the Arctic. The study also shows how it will become both hard and expensive to solve the problem worsened by destabilized natural systems triggered by human-made emissions.
The known stocks of organic matter that is frozen in the ground up to 3 metres deep at multiple points across the Arctic is assessed and run through the world’s most advanced simulation software in the US and at the UK Met Office for the prediction of the amount of gas that will release at different levels of warming.
The supercomputers even took weeks to crunch the number as the Arctic’s vast geography, and complex climate interactions throw up multiple variables. Following that, previous economic impact models are put to use by the researchers to determine the estimated costs.
However, the main concern remains the melting of permafrost. Greenhouse gases usually get released when organic matter remaining frozen for centuries below the soil thaws and rots. Now, at the current level of 1 degrees Celsius of global warming, they have already started to release. Still, the impact is less. Around ten gigatonnes of carbon have been released from the permafrost but once temperatures rise beyond 1.5C, there will be rapid growth in emissions from this source.
Considering the current trend of minimum 3C of warming by the century end, discharge of up to 280 gigatonnes of carbon dioxide and 3 gigatonnes of methane is estimated from the melting permafrost and that will have a 10 to 20 times stronger climate effect compared to carbon dioxide.
As per the paper, the melting Arctic may have the projected benefits like navigation for ships will be easier and we will get access to minerals, but increase in the global climate-driven impacts will be 10 times higher which is $70tn between now and 2300.
It would encourage global inequality as the countries like India and Africa which are in poorer warmer regions and vulnerable to a rise in temperatures will bear most of the economic burden and that is almost equivalent to the current annual GDP of the whole world.
“It’s disheartening that we have this in front of us,” said Dmitry Yumashev of Lancaster University. “Even at 1.5C to 2C, there are impacts and costs due to thawing permafrost. However, they are considerably lower for these scenarios compared to business as usual. We have the technology and policy instruments to limit warming, but we are not moving fast enough.”
However, there is a little good news in the new projections. The land permafrost melt impact was at the lower range of what had been feared. In contrary to what was previously suggested like the tipping points of Arctic could add 10% and more to climate costs or alone methane could prove catastrophic; CO2 remains the most significant concern as per the new figures.
“We still have a time bomb, but it may not be as large as previously believed,” said Yumashev. Although the study contains a considerable degree of uncertainty and it has not yet calculated the costs of several other potential tipping points, still we shouldn’t be complacent because the damages are huge even at the low end, warned Yumashev.