Global warming good for rainforests – Smithsonian

Rainforests flourished under conditions of global warming in the past and should do so in the future, say scientists at the Smithsonian Tropical Research Institute.

Researchers Carlos Jaramillo and Andrés Cárdenas reviewed nearly 6,000 publications about ancient temperature measurements to give a perspective to the debate on climate change. Their conclusions were published on the institute's web site June 1.

Currently, no South American rainforest is subject to average annual temperatures of more than 84 degrees Fahrenheit (29 Celsuis). But by the end of this century, global average temperatures will rise to above that level.
Some scientists have postulated that climate change will see the disappearance to the most diverse terrestrial ecosystems.
However, Jaramillo said that the fossil record shows that tropical forests thrived under global warming conditions and diversity increased, since larger forested areas generally have a level of diversity that is higher than in smaller areas.
The research showed that rainforests expanded into more temperate zones as temperatures increased.
The prognosis of the researchers is based on indirect evidence, such as the proportions of oxygen isotopes in the fossil shells of marine organisms or biomarkers in bacteria.
Jaramillo emphasized that 120 million years ago, in the Middle Cretaceous period, intense volcanic activity produced huge amounts of carbon dioxide increasing temperatures by 12.9 degrees Fahrenheit (10.6 Celsius).
Klaus Winter, a plant physiologist, discovered that some tropical trees tolerate exposure to short-term temperature of up to 127 degrees F (53 Celsius)