London, Nov 28 (Inditop.com) The forests and grasslands of Europe could have absorbed 19 percent of the global-warming greenhouse gases emitted by the continent, if intensive land management had not ruined this carbon sink, so that it now absorbs only two percent, a new study has found.
Of all global carbon dioxide emissions, less than half accumulate in the air where it contributes to global warming. The other half is absorbed in oceans and forests, grasslands and peat-lands.
Researchers from 17 European countries cooperating in the EU-Integrated Project CarboEurope, led by Detlef Schulze, of the Max Planck Institute for Biogeochemistry in Jena, Germany, have compiled the first in-depth greenhouse gas balance of Europe.
They made two independent estimates: one based on what the atmosphere sees and one based on what terrestrial ecosystems see.
The new bookkeeping effort confirmed the existence of a strong carbon sink of 305 million tonnes of carbon per year in European forests and grasslands. A sink of this magnitude could offset 19 percent of Europe’s emissions from fossil fuel burning.
However, agricultural land and drained peat-land are emitting carbon dioxide, which cancels part of this sink. The resulting net carbon dioxide sink of the European continent is 274 million tonnes of carbon per year, only 15 percent of the emissions.
But this balance is still incomplete, because all European ecosystems are managed and as a by-product of land management other powerful greenhouse gases are released — for example nitrous oxide from fertilisers applied to grassland and crops.
These previously neglected emissions of greenhouse gases from land use cancel out almost the entire carbon sink, leaving the landscape offsetting only two percent of carbon dioxide emissions from households, transport and industry, said a Max Planck release.
Schulze, a professor, said: “These findings show that if the European landscape is to contribute to mitigating global warming, we need a new, different emphasis on land management. Methane and nitrous oxide are such powerful greenhouse gases; we must manage the landscape to decrease their emissions.”
These findings are presented in the latest edition of Nature Geoscience.
