Araucarias gauge ancient levels of carbon dioxide
Friday, April 29, 2011 - 12:00
in Earth & Climate
One way of telling how much carbon dioxide was in the atmosphere in the past is by counting pores (or stomata) in leaves the tiny openings plants use to absorb CO2 and lose water. It may seem far-fetched, but plants tend to decrease the number of pores when the atmospheric CO2 is increased.