Envisat makes first ever observation of regionally elevated CO2 from manmade emissions

"This does not mean, however, that the anthropogenic fluxes are of minor importance. In fact, the opposite is true because the manmade fluxes are only going in one direction whereas the natural fluxes operate in both directions, taking up atmospheric CO₂ when plants grow, but releasing most or all of it again later when the plants decay. This results in higher atmospheric CO₂ concentrations in the first half of a year followed by lower CO₂ during the second half of a year with a minimum around August.

"That we are able to detect regionally elevated CO₂ over Europe shows the high quality of the SCIAMACHY CO₂ measurements."

Buchwitz says further analysis is required in order to draw quantitative conclusions in terms of CO₂ emissions. "We verified that the CO₂ spatial pattern that we measure correlates well with current CO₂ emission databases and population density but more studies are needed before definitive quantitative conclusions concerning CO₂ emissions can be drawn."

Significant gaps remain in the knowledge of carbon dioxide’s sources, such as fires, volcanic activity and the respiration of living organisms, and its natural sinks, such as the land and ocean.

"We know that about half of the CO₂ emitted by mankind each year is taken up by natural sinks on land and in the oceans. We do not know, however, where exactly these important sinks are and to what extent they take up the CO₂ we are emitting, i.e., how strong they are.

"We also don’t know how these sinks will respond to a changing climate. It is even possible that some of these sinks will saturate or turn into a CO₂ source in the future. With our satellite measurements we hope to be able to provide answers to questions like this in order to make reliable predictions," Buchwitz said.

By better understanding all of the parameters involved in the carbon cycle, scientists can better predict climate change as well as better monitor international treaties aimed at reducing greenhouse gas emissions, such as the Kyoto Protocol which addresses the reduction of six greenhouse gases.

Last year, European Union leaders highlighted the importance of cutting emissions from these manmade gases by endorsing binding targets to cut greenhouse gases by at least 20 percent from 1990 levels by 2020.