Plants and CO2

Another nail in the global coffin No plant CO2 relief in warm world.

Plants take up less CO2 under warmer/drier conditions (like what is expected to happen over large swathes of the worlds grasslands.

"So in the warm year, the temperature goes up and causes more evapotranspiration from the plants," he (Jay Arnone, who led the study) told BBC News.

"But plants have evolved to 'know' that when it gets dry they should curb their water loss, so they reduce the apertures of their stomata (pores) to conserve water, and that constrains the amount of CO2 they can take up (by photosynthesis)."

In addition warmer temperatures meant that bacteria degraded extra carbon resulting in a net release of carbon to the atmosphere.