Terrestrial ecosystems draw about 123 billion tonnes of carbon (450 billion tonnes of carbon dioxide, CO2) from the atmosphere each year. Based on worldwide local measurements and data-driven model simulations, an international team of researchers led by Christian Beer of the Max Planck Institute for Biogeochemistry in Jena has for the first time provided an observation-based estimate of the largest global flux of carbon between land and atmosphere and of its climate dependencies.
The researchers evaluated the result against spatially explicit process models including the leading model LPJmL from PIK. Tropical ecosystems such as rain forests and savannas account for almost two thirds of the CO2 uptake, they report in an article published by the journal …

A new study shows the Arctic climate system may be more sensitive to greenhouse warming than previously thought, and that current levels of Earth’s atmospheric carbon dioxide may be high enough to bring about significant, irreversible shifts in Arctic ecosystems.
Led by the University of Colorado at Boulder, the international study indicated that while the mean annual temperature on Ellesmere Island in the High Arctic during the Pliocene Epoch 2.6 to 5.3 million years ago was about 34 degrees Fahrenheit, or 19 degrees Celsius, warmer than today, CO2 levels were only slightly higher than present. The vast majority of climate scientists agree Earth is warming due to increased concentrations of heat-trapping atmospheric gases generated primarily by …