Arctic fires could release catastrophic amounts of C02

Syllabus: General Studies Paper 3

The recent fires themselves have spewed some 150 million tonnes of carbon into the atmosphere.

Finding

• Global warming is responsible for bigger and bigger fires in Siberia, and in the decades ahead they could release huge amounts of carbon now trapped in the soil.
• In 2019 and 2020, fires in this remote part of the world destroyed a surface area equivalent to nearly half of that which burned in the previous 40 years.
• These recent fires themselves have spewed some 150 million tonnes of carbon into the atmosphere, the scientists estimate, contributing to global warming in what researchers call a feedback loop.
• The area above the Arctic circle heats up four times faster than the rest of the planet and “it is this climate amplification which causes abnormal fire activity,”
• Researchers concentrated on an area five and a half times the size of France and with satellite pictures observed the surface area burned each year from 1982 to 2020.
• In 2020, fire charred more than 2.5 million hectares (6.2 million acres) of land and released, in CO2 equivalent, as much as that emitted by Spain in one year, the scientists concluded.
• That year, summer in Siberia was on average three times hotter than it was in 1980. The Russian city of Verkhoyansk hit 38 degrees Celsius in summer, a record for the Arctic.

Polar Amplification

• Polar amplification happens when changes to the earth’s atmosphere lead to a larger difference in temperature near the north and south poles than to the rest of the world.
• This phenomenon is measured against the average temperature change of the planet.
• These changes are more pronounced at the northern latitudes and are known as the Arctic amplification.
• It occurs when the atmosphere’s net radiation balance is affected by an increase in greenhouse gases (GHGs) .

Reasons for Polar Amplification

• The ice-albedo feedback, lapse rate feedback, water vapour feedback (Change in Water Vapour amplify or weaken temperature range) and ocean heat transport are the primary causes.
• Sea ice and snow have high albedo (measure of reflectivity of the surface), implying that they are capable of reflecting most of the solar radiation as opposed to water and land.
• As the sea ice melts, the oceans surrounding poles will be more capable of absorbing solar radiation, thereby driving the amplification.
• The lapse rate or the rate at which the temperature drops with elevation decreases with warming.

The consequences of Arctic Warming/ Polar Amplification

• Glacial retreat
• Thinning of Ice Sheet
• Rise in Sea Level
• Impact on Biodiversity: The warming of the poles and the seas in the region, the acidification of water, changes in the salinity levels, is impacting biodiversity, including the marine species and the dependent species.
• Thawing of Permafrost: it releases carbon and methane which are among the major greenhouse gases responsible for global warming.
• Experts fear that the thaw and the melt will also release the long-dormant bacteria and viruses that were trapped in the permafrost and can potentially give rise to diseases.
• The best-known example of this is the permafrost thaw leading to an anthrax outbreak in Siberia in 2016, where nearly 2,00,000 reindeer succumbed.

Source of Permafrost

• Arctic soils store huge amounts of organic carbon, much of it in peatlands. This is often frozen or marshy, but climate warming thaws and dries peatland soil, making large Arctic fires more likely.
• Fire damages frozen soil called permafrost, which releases even more carbon. In some cases, it has been trapped in ice for centuries or more. This means that carbon sinks are transformed into sources of carbon.
• An elevated amount of CO2 was released in 2020 but things “could be even more catastrophic than that in the future,” said the report.
• Higher temperatures have a variety of effects: more water vapor in the atmosphere, which causes more storms and thus more fire-sparking lightning. And vegetation grows more, providing more fuel for fire, but it also breathes more, which dries things out.