Record Greenhouse Gases: Devastating Effects on Antarctic Permafrost



by LORENZO CIOTTI

Record Greenhouse Gases: Devastating Effects on Antarctic Permafrost

Antarctica is emitting massive amounts of harmful greenhouse gases. A worrying figure, which has devastating effects on the permafrost. A recent study focused on the McMurdo Dry Valleys, the largest ice-free area on the Antarctic continent.

It represents 10% of all ice-free land at the South Pole. Measurements were made on the concentration of greenhouse gases in the atmosphere and in the soil. The emission of carbon dioxide in the summer is about 448.5 t per month for the entire aforementioned area.

Giancarlo Ciotoli, Cnr-Igag researcher, said, as reported by the Italian website LegaNerd: "The simultaneous presence of anomalies of several gaseous species in the soil of the McMurdo Dry Valleys has allowed the identification of areas characterized by the melting of the active level of permafrost and where the presence of tectonic structures and/or fractures allows these gases to migrate towards the surface. Preliminary data suggest the presence of high quantities of dissolved gases in the brine system under pressure under the permafrost."

About Greenhouse Gases

The contribution of a gas to the variation of the greenhouse effect is determined by the radiative forcing of the gas, by its concentration in the atmosphere and by its residence time in the atmosphere.

The index known as Global Warming Potential, which represents the combined effect of the residence time in the atmosphere of each gas and the relative specific effectiveness in the absorption of infrared radiation emitted by the Earth, is a measure of how much a given greenhouse gas contributes to the global warming, commensurate with CO2, taken as a benchmark and whose GWP has by definition the value 1.

GWPs are calculated by the Intergovernmental Panel on Climate Change and are used as conversion factors to calculate the emissions of all greenhouse gases in equivalent CO2 emissions. Carbon dioxide, whose molecule has the formula CO2, is responsible for 5-20% (the most accredited theory is 15%) of the natural greenhouse effect and interacts with the atmosphere for natural and anthropic causes.

The natural reservoirs of CO2 are the oceans, fossil sediments, the terrestrial biosphere, the atmosphere. Much of the carbon dioxide from ecosystems is emitted into the atmosphere. A number of organisms have the ability to assimilate atmospheric CO2.

Carbon, thus, thanks to the photosynthesis of plants, which combines carbon dioxide and water in the presence of solar energy, enters the organic compounds and therefore the food chain, finally returning to the atmosphere through respiration.

Annual variations in atmospheric CO2 concentration can be identified. During the winter there is an increase in concentration due to the fact that respiration prevails in deciduous plants; while during the summer the concentration of atmospheric CO2 decreases due to the total increase in photosynthesis.