Tropical Tree Growth Slowed
Other big changes are being monitored in the tropics, too. Data on tree growth, tropical air temperatures and CO2 readings collected over 16 years indicate that a warming climate may cause the tropical forests to give off more carbon dioxide than they take up. This would upset the common belief that tropical forests are always a counterbalance to carbon, taking huge amounts out of the atmosphere. The study, by Deborah and David Clark of the La Selva Biological Station in Costa Rica, and Charles Keeling and Stephen Piper of the Scripps Institution, reports that rainforest trees grow much more slowly in warmer nighttime temperatures, which is a hallmark of climate change in the tropics.