November 11, 1999
Laboratory tests indicate gradual global warming can lead to major extinctions, including those of such "charismatic" animals as lions, tigers — and humans, scientists report.
They say the warming results in the extinction of predators and herbivores, which alters the rate at which plants grow and consume the greenhouse gas carbon dioxide.
The scientists from Rutgers University in New Brunswick, N.J., say this is the first time researchers have warmed an ecosystem in the lab to determine the effect. They found an alarming number of species at the top of the food chain suffered extinction in the study.
"This is the first time researchers have examined ecosystems by gradually warming them", said Owen Petchey of Rutgers' Biodiversity Center at Cook College. "Considering the interest in global warming, we found that surprising".
The team examined aquatic microbes in bottles, which acted as model worlds. The investigators studied how ecosystems containing different numbers of species respond to simulated warming of the environment. The control ecosystems had no change in temperature, while the others experienced gradual increases in temperature.
"Alarmingly, a lot of species near the top of the food chain suffered extinction", Petchey said in a report in the British journal Nature.
"Such species in the real world would include charismatic animals such as lions and tigers — and also human beings".
Overall, the experiment showed ecosystems with temperature increases lost more species than those with unchanging environments.
"Those with a higher number of species before warming ended up with more species after warming", Petchey said. "This is an excellent argument for conserving biodiversity".