Earth’s Carbon Cycle Pivotal For Climate

The layer of ice that covers an extensive tract of land covers about ten percent of the surface of Earth at present, were thought 20 years ago to be frozen wilderness, lacking life.
Now a very powerful international team, guided by Professor Jemma Wadham from the University of Bristol' School of Geographical Sciences and Cabot Institute for the Environment, have undertaken a wealth of evidence issued over the last 20 years to give a demonstration that ice sheets cannot any more be considered as passive parts and frozen parts of the carbon cycle of Earth.
Their discoveries are brought out today in the magazine Nature Communications.
Professor Wadham said that a special set of conditions present underneath ice sheets make them chief reactors in the carbon cycle of Earth.
Here, crushing of rock by operating ice is high, liquid water is plentiful and microbes flourish in melt zones in spite of bleak state -- the ice sheets wear away their bedrock, glacial melt-waters send overseas this nutritional ingredient to the oceans, also invigorating the upwelling of farther nutrient from deep at glacier marine margins and cold-adapted microorganisms act on the ground rock and uplift nutrient release.
All these nourishing elements support fisheries and raise the rate of decrease of carbon dioxide (CO2) from the atmosphere.
Co-author Rob Spencer Professor of Florida State University said that Ice sheets are also very powerful at keeping in reserve huge amounts of carbon that grow over soil, marine sediments and vegetation.
The Antarctic Ice Sheet by itself potentially stows up to twenty thousand billion tonnes of organic carbon which is ten times additional than that roughly calculated for Northern Hemisphere permafrost.
Small amount of this carbon is set free in fuels and melt-waters of marine food webs. The carbon that is abandoned in deep parts of ice sheets is transformed to methane gas by geothermal activity or by microbial activity, which has the power to be stored in the form of solid methane hydrate under high pressure conditions and low temperatures.

By: Prerana Sharma
Content: https://www.sciencedaily.com/releases/2019/08/190815081256.htm