A study on California's grasslands has shown that this particular ecosystem will not be able to help reduce the effects of global warming in the future. Some scientists believe that as carbon dioxide emissions increase, natural ecosystems may be able to buffer the effects by taking up more carbon dioxide.
Biologist Jeffrey Dukes from UMass Boston and his colleagues have released their research findings from a five-year experiment on the grasslands. Trial plots were exposed to elevated carbon dioxide levels, elevated temperatures, precipitation and nitrogen levels. The nitrogen levels had much larger effects than changes in the other factors.
Dukes commented, "Our study suggests that despite earlier predictions that ecosystems would take up a lot more carbon, this may not always be the case and we can't rely on all ecosystems to do that. If it turns out that other natural systems also fail to sequester as much carbon as scientists once thought, carbon dioxide concentrations will rise even faster than expected."