A new study by a team of NASA scientists researching large-scale climate change in Alaska and Canada, a project of NASA's Arctic-Boreal Vulnerability Experiment (ABoVE), found significant methane hotspots over the burn scars from wildfires in Alaska’s tundra. The region studied is the Yukon-Kuskokwim Delta, one of Earth's largest deltas, where the rivers flow into the Bering Sea on Alaska’s west coast.
In Alaska’s largest river delta, tundra that carbon-heavy peat and bog-frozen soils that have burned by wildfire emit, long after the fires were extinguished, contained more methane than surrounding tundra that has not burned by twenty-nine percent. That correlation triples “in areas where a fire burned to the edge of a lake, stream, or other standing-water body. The highest ratio of hot spots occurred in recently burned wetlands.” The phenomenon alters the carbon emissions in the Arctic.
Nasa Jet Propulsion library writes:
The researchers first observed the methane hot spots using NASA’s next-generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG) in 2017. Mounted on the belly of a research plane, the instrument has an optical sensor that records the interaction of sunlight with molecules near the land surface and in the air, and it has been used to measure and monitor hazards ranging from oil spills to crop disease.
Roughly 2 million hot spots – defined as areas showing an excess of 3,000 parts per million of methane between the aircraft and the ground – were detected across some 11,583 square miles (30,000 square kilometers) of the Arctic landscape. Regionally, the number of hot spot detections in the Yukon-Kuskokwim Delta were anomalously high in 2018 surveys, but scientists didn’t know what was driving their formation.
“What we uncovered is a very clear and strong relationship between fire history and the distribution of methane hot spots,” said Yoseph, lead author of the new study.
The connection arises from what happens when fire burns into the carbon-rich frozen soil, or permafrost, that underlies the tundra. Permafrost sequesters carbon from the atmosphere and can store it for tens of thousands of years. But when it thaws and breaks down in wet areas, flourishing microbes feed on and convert that old carbon to methane gas. The saturated soils around lakes and wetlands are especially rich stocks of carbon because they contain large amounts of dead vegetation and animal matter.
Because of the cool marshes, low shrubs, and grasses, tundra wildfires are relatively rare compared to those in other environments, such as evergreen-filled forests. However, by some projections the fire risk in the Yukon-Kuskokwim Delta could quadruple by the end of the century due to warming conditions and increased lightning storms – the leading cause of tundra fires. Two of the largest tundra fires on record in Alaska occurred in 2022, burning more than 380 square miles (100,000 hectares) of primarily tundra landscapes.
More research is needed to understand how a future of increasing blazes at high latitudes could impact the global climate. Arctic permafrost holds an estimated 1,700 billion metric tons of carbon – roughly 51 times the amount of carbon the world released as fossil fuel emissions in 2019.
All that stored carbon also means that the carbon intensity of fire emissions from burning tundra is extremely high, said co-author Elizabeth Hoy, a fire researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Tundra fires occur in areas that are remote and difficult to get to, and often can be understudied,” she noted. “Using satellites and airborne remote sensing is a really powerful way to better understand these phenomena.”
The severity, frequency, and types of wildfires have changed in the Arctic. The fires are starting earlier and ending later in the season. It is a frightening development that has slowly unfolded over decades.
These changes to the climate also occur in Canada. They are particularly worrisome in Siberia, where permafrost is blanketed in record-high summer temperatures with some of the worst heat waves in recorded history.
The media ignores this type of news. An example is the news that 2023 will pass the 1.5 threshold the Paris Climate Accords set and will be the warmest year in over 125,000 years.
Tatiana Kondratenko writes about the devastating news that the Arctic has warmed by three degrees centigrade or 5.4 Fahrenheit.
When a human being's temperature rises from a healthy 36.6 to 38.6 degrees Celsius (97.8 to 101.48 degrees Fahrenheit), it has consequences. Just a seemingly minor increase leaves the body feeling unwell and unable to function normally.
It's a similar story for the planet.
Since the late 19th century, when burning fossil fuels was becoming more widespread, the Earth has warmed by an average of more than 1 degree Celsius. Some places, however, have warmed beyond that level.
One of them is the Arctic. According to the Arctic Monitoring and Assessment Programme (AMAP), a working group of the intergovernmental Arctic Council, the average annual temperature in the region jumped by 3 degrees Celsius between 1971 to 2019. And that spells big problems for the region's ecosystem.
Meanwhile, in South Florida:
ORLANDO, Fla.—It used to be the water spilled over Lake Okeechobee’s southern shore, flowing eventually into the sawgrass prairies of the Florida Everglades. For thousands of years the marsh vegetation flourished and died here in an endless cycle, the plant remains falling beneath the slow-coursing water to form a rich layer of organic soil called peat.
Over time the fertile soil, along with the subtropical climate and abundance of water, drew the attention of farmers, who as far back as the 1880s began digging canals to drain away the water and expose the peat for planting.
Today this region, known as the Everglades Agricultural Area, is among the nation’s most bountiful, raising rice, sod, vegetables like lettuce, celery and corn and most notably sugar cane, making Florida the country’s top producer of the crop.
Growing evidence suggests that draining the water and exposing the peat also has made the region a significant source of greenhouse gas emissions, which are warming the global climate and contributing to impacts like hotter temperatures, rising seas and more damaging hurricanes.