Thawing permafrost could leach microbes and chemicals into the environment
Then there’s the effect of thawing permafrost on the planet’s carbon: Arctic permafrost alone contains about 1.7 trillion metric tons of carbon, including methane and carbon dioxide. That’s about 51 times the amount of carbon the world released as fossil fuel emissions in 2019. Frozen plant matter in permafrost doesn’t break down, but when permafrost thaws, microbes in the material dead plant material begin to decompose, releasing carbon into the atmosphere.
“Current models predict that we will see a pulse of carbon released from permafrost into the atmosphere over the next hundred years, potentially sooner,” said Kimberley Miner, a climate researcher at NASA’s Jet Propulsion Laboratory in California. South and lead author of the paper. But key details – such as the amount, specific source and duration of carbon release – remain unclear.
The worst case scenario would be for all the carbon dioxide and methane to be released in a very short time, like a few years. Another scenario involves the gradual release of carbon. With more information, scientists hope to better understand the likelihood of either scenario.
While the briefing paper found that Earth’s polar regions are warming the fastest, it was less conclusive about how increased carbon emissions could lead to drier or wetter conditions in the Arctic. What is more certain is that changes in the Arctic and Antarctic will affect lower latitudes. The Earth’s polar regions help stabilize the planet’s climate. They contribute to the transfer of heat from the equator to higher latitudes, resulting in atmospheric circulation that fuels the jet stream and other currents. A warmer, permafrost-free Arctic could have incalculable consequences for Earth’s weather and climate.
An integrated approach
To understand the effects of the thaw, scientists are increasingly turning to integrated observations of the Earth from the ground, air and space – techniques described in the article. Each approach has its advantages and disadvantages.
Ground-based measurements, for example, provide precise monitoring of changes in a localized area, while aerial and space-based measurements can cover large areas. Ground and airborne measurements focus on the precise moment they were collected, while satellites constantly monitor the Earth – although they can be limited by things like cloud cover, time of day or the eventual termination of a satellite mission.
The hope is that using measurements from a combination of platforms will help scientists create a more complete picture of changes at the poles, where permafrost is melting fastest.
Miner works with colleagues in the field to characterize microbes frozen in permafrost, while others use airborne instruments to measure emissions of greenhouse gases like methane. Additionally, airborne and satellite missions can help identify emission hotspots in permafrost regions.
There are also satellite missions in the works that will provide carbon emissions data with greater resolution. The ESA (European Space Agency) Copernicus hyperspectral imaging mission will map changes in land cover and help monitor soil properties and water quality. NASA’s Surface Biology and Geology (SBG) mission will also use satellite imagery spectroscopy to collect data on research areas, including plants and their health; terrain changes related to events such as landslides and volcanic eruptions; and the accumulation, melting and brightness of snow and ice (which is related to the amount of heat reflected back into space).
SBG is the focus area of one of the many future Earth science missions that make up NASA’s Earth System Observatory. Together, these satellites will provide a 3D global view of the Earth, from its surface through the atmosphere. They will provide information on topics such as climate change, natural hazards, extreme storms, water availability and agriculture.
“Everyone is running as fast as they can to figure out what’s going on at the poles,” Miner said. “The more we understand, the better prepared we will be for the future.”