In other studies, analysis of water and oxygen components found in ocean sediments and ice cores have provided scientists with a 'big picture' insight into carbon cycling over millions of years, but the search for the finer details of exchanges or uptake through ocean algae and terrestrial plant leaves has been out of reach.
The authors said that their new estimate of the rate of global photosynthesis will help guide other estimates of plant activity, such as the capacity of forests and crops to grow and fix carbon, and help re-define how scientists measure and model the cycling of CO2 between the atmosphere and plants on land and in the ocean.
Dr Allison said understanding the exchange of gases, including CO2 and water vapour, in the biosphere oceans, land and atmosphere is especially significant to climate science, and to policymakers, because of its relevance to global management of carbon emissions.
"Quantifying this global production, centred on the exchange of growth-promoting CO2 and water vapour, has been historically difficult because there are no direct measurements at scales greater than leaf levels.
"Inferences drawn from atmospheric measurements provide an estimate of ecosystem exchanges and satellite-based observations can be used to estimate overall primary production, but as a result of this new research we have re-defined the rate of biospheric carbon exchange between atmosphere, land and ocean.
"These results can be used to validate the biospheric components included in carbon cycle models and,
|Contact: Craig Macaulay|