Credit: Edwin Remsberg

Climate change skeptics have an arsenal of arguments for why humans need not cut their carbon emissions. Some assert rising CO2 levels benefit plants, so global warming is not as bad as scientists proclaim. “A higher concentration of carbon dioxide in our atmosphere would aid photosynthesis, which in turn contributes to increased plant growth,” Rep. Lamar Smith (R–Texas) wrote in an op-ed last year. “This correlates to a greater volume of food production and better quality food.” Scientists and others calling for emission cuts are being hysterical, he contends.

So is it true rising atmospheric CO2 will help plants, including food crops? Scientific American asked several experts to talk about the science behind this question.

There is a kernel of truth in this argument, experts say, based on what scientists call the CO2 fertilization effect. “CO2 is essential for photosynthesis,” says Richard Norby, a corporate research fellow in the Environmental Sciences Division and Climate Change Science Institute of Oak Ridge National Laboratory. “If you isolate a leaf [in a laboratory] and you increase the level of CO2, photosynthesis will increase. That’s […]