Frozen for thousands of years in Arctic permafrost, billions of tons of carbon and methane are slowly being released into the atmosphere due to rising temperatures. A new study shows that while the release is slow, continued thawing of this permafrost will significantly impact Earth’s climate.
The Arctic is warming more than twice as fast as the rest of the world, and some scientists believe that thawing permafrost — ground frozen since the last Ice Age — is about to release enormous amounts of climate-warming emissions.
Between 1994 and 2017, an incredible 28 trillion tonnes (31 trillion tons) of ice was lost from the Earth’s ice sheets, glaciers, and mountains, according to a new report in the journal The Cryosphere. The extent of this worldwide melting has been described as “staggering” by the study authors, who warn that the ongoing loss of ice could lead to catastrophic rises in sea levels.
Researchers from University College London, Leeds University, and Edinburgh University studied satellite data in order to determine global changes in ice coverage over several decades. Speaking to The Guardian, study author Andrew Shepherd explained that “in the past researchers have studied individual areas – such as the Antarctic or Greenland – where ice is melting. But this is the first time anyone has looked at all the ice that is disappearing from the entire planet.”
Abstract: Soil organic carbon (SOC) stored in permafrost across the high-latitude/altitude Northern Hemisphere represents an important potential carbon source under future warming. Here, we provide a comprehensive investigation on the spatiotemporal dynamics of SOC over the high-altitude Tibetan Plateau (TP), which has received less attention compared with the circum-Arctic region. The permafrost region covers ~42% of the entire TP and contains ~37.21 Pg perennially frozen SOC at the baseline period (2006–2015). With continuous warming, the active layer is projected to further deepen, resulting in ~1.86 ± 0.49 Pg and ~3.80 ± 0.76 Pg permafrost carbon thawing by 2100 under moderate and high representative concentration pathways (RCP4.5 and RCP8.5), respectively. This could largely offset the regional carbon sink and even potentially turn the region into a net carbon source. Our findings also highlight the importance of deep permafrost thawing that is generally ignored in current Earth system models
Permafrost collapse is accelerating carbon release
Merritt R. Turetsky, Benjamin W. Abbott, Miriam C. Jones, Katey Walter Anthony, David Olefeldt, Edward A. G. Schuur, Charles Koven, A. David McGuire, Guido Grosse, Peter Kuhry, Gustaf Hugelius, David M. Lawrence, Carolyn Gibson & A. Britta K. Sannel
The sudden collapse of thawing soils in the Arctic might double the warming from greenhouse gases released from tundra, warn Merritt R. Turetsky and colleagues.
This kind of positive feedback loop entails nonlinear effects, which increases uncertainty and underscores the importance of swift and decisive action by policy makers and business leaders. Riskthinking.ai’s tools can help.