Plant physiologist Dr. Bert Drake presented an overview of the results of the world's longest-running study on elevated CO₂ at the December American Geophysical Union meetings in San Francisco.

In his 17-year continuous field study, Drake has been exposing various species of wetland grasses to elevated CO₂ in enclosed chambers.

"The response of the wetland to elevated CO₂ has been increasing over this long period, rather than decreasing as many would have predicted," Drake says.

"Our main findings support the conclusion that rising atmospheric CO₂ will increase the carbon content of many terrestrial ecosystems but that the amount of anthropogenic carbon they sequester will not be enough to offset the ever increasing CO₂ from burning fossil fuels and deforestation."