Alcide Giorgio di Sarra: Carbon cycle, climate, and implications for the Mediterranean.

Speaker: Alcide Giorgio di Sarra

Title: Carbon cycle, climate, and implications for the Mediterranean

Abstract: Greenhouse gases (GHGs) have the capability to absorb infrared radiation, and although their atmospheric concentration is very low, they play a disproportionate influence on the Earth's climate. The atmospheric concentration of carbon containing GHGs, in particular CO2 and CH4, is the result of complex interactions among different components of the Earth's system. Anthropogenic emissions are interfering with the natural carbon cycle, and it will be shown that are at the origin of the observed atmospheric CO2 growth. Natural exchanges between atmosphere and ocean, and atmosphere and terrestrial vegetation are offsetting about 50% of the anthropogenic perturbation to the atmospheric CO2 content.  Due to the complexity and variability of the system, measurements dedicated to the carbon cycle are essential to understand present and future climate change.
The seminar will also discuss basic processes linking concentration of atmospheric GHGs and climate, and in particular the induced perturbation of the Earth radiation balance. Measurements of carbon cycle made in the Mediterranean, and some recent results on the influence of marine heat waves on atmosphere-ocean CO2 exchange will be also shown, also in relation to uncertainties and complex feedback mechanisms of the climate system.