Thawing permafrost peatlands ‘on the precipice’ of releasing billions of tonnes of carbon

‘Magnitude of 21st century climate change likely to overwhelm’ critical carbon stores, new study warns

Melting permafrost peatlands release methane and carbon into the atmosphere, increasing warming further (Getty)

Global warming is pushing frozen peatlands in northern Europe and Siberia to the brink of a tipping point which could release 39 billion tonnes of carbon, researchers have warned.

“Even with the strongest efforts” to slash global carbon emissions and limit rising temperature, by 2040 the climates of northern Europe will no longer be cold and dry enough to sustain peat permafrost, a new study by academics at the University of Leeds found.

The peatlands store twice as much carbon as all of Europe's forests but the climate crisis means these critical ecosystems are even closer to collapse than previously thought, researcher said.

However, they said the strongest efforts to cut emissions could preserve the permafrosts in northern parts of western Siberia, where 13.9 billion tonnes of carbon are stored.

The large quantities of carbon stored in peatland permafrost soils are particularly threatened by rapid 21st-century climate change, in which temperatures are rising faster closer to the Arctic.

When permafrost thaws the organic matter stored within them starts to decompose, releasing greenhouse gases such as carbon dioxide and methane, which increase global temperatures and potentially accelerate the climate crisis.

Study co-author Dr Paul Morris, an associate professor of biogeoscience at Leeds, said: “Huge stocks of peat carbon have been protected for millennia by frozen conditions but once those conditions become unsuitable all that stored carbon can be lost very quickly.

“The magnitude of 21st century climate change is likely to overwhelm any protection the insulating properties of peat soils could provide.”

The researchers said their work should emphasise the importance of policies designed to reduce emissions of climate-altering greenhouse gases, mitigate the impacts of the climate crisis and add weight to the importance of the e in determining the rate and extent of permafrost peatland thaw.

The researchers said their work emphasises the need for policies to reduce emissions, mitigate the climate crisis and improve the understanding of how well they can impact peatlands.

Richard Fewster a PhD researcher at Leeds and the paper's lead author, said: “We examined a range of future emission trajectories. This included strong climate-change mitigation scenario, which would see large-scale efforts to curb emissions across sectors, to no-mitigations scenarios and worse-case scenarios.

“Our modelling shows that these fragile ecosystems are on a precipice and even moderate mitigation leads to the widespread loss of suitable climates for peat permafrost by the end of the century.“

He added: “But that doesn’t mean we should throw in the towel. The rate and extent to which suitable climate is lost could be limited, and even partially reversed, by strong climate-change mitigation policies.”

Study co-author Dr Ruza Ivanovic, associate professor in climatology at Leeds said: “Peatland permafrost responds differently to changing climates than mineral-soil permafrost due to the insulating properties of organic soils, but peatlands remain poorly represented in Earth system models.

“It is vitally important these ecosystems are understood and accounted for when considering the impact of climate change on the planet.”

The research is published in the journal Nature Climate Change.