atmospheric carbon dioxide

The prevailing view among scientists is that global climate change may prove beneficial to many farmers and foresters — at least in the short term. The logic is straightforward: Plants need atmospheric carbon dioxide to produce food, and by emitting more CO2 into the air, our cars and factories create new sources of plant nutrition that will cause some crops and trees to grow bigger and faster. But an unprecedented three-year experiment conducted at Stanford University is raising questions about that long-held assumption. Writing in the journal Science, researchers concluded that elevated atmospheric CO2 actually reduces plant growth when combined with other likely consequences of climate change — namely, higher temperatures, increased precipitation or increased nitrogen deposits in the soil.