ENVIRONMENT: A Third of Species Could Face Extinction

By Sanjay Suri Reprint | | Print |

Sanjay Suri

LONDON, Jan 8 2004 (IPS) - Up to a third of animal and plant species could face extinction by 2050 due to climate change, says a major new study by international scientists.

The study suggests that between 15 to 37 percent of a sample of 1,103 land plants and animals would become extinct by that date.

“For some of these species there will no longer be anywhere suitable to live,” says the study published Thursday in the magazine Nature. “Others will be unable to reach places where the climate is suitable.”

Friends of the Earth International (FoEI) called the findings of the study “terrifying”.

The scientists used projections of species distribution for future climate scenarios over about 20 percent of the earth’s terrestrial surface.

“These estimates show the importance of rapid implementation of technologies to decrease greenhouse gas emissions and strategies for carbon sequestration,” the report says. “A rapid shift to technologies that do not produce greenhouse gases could save 15 to 20 percent of species from extinction.”

At the present rate earth is “set to become warmer than at any period in the past,” the study says.

The scientists looked at the link between current climates and species distribution to develop models of a “climate envelope”. The model represents conditions under which “populations of a species currently persist in the face of competitors and natural enemies.” It then looks at possibilities of dispersal in the light of projected climate change.

The study used three methods to estimate extinction based on the species- area relationship. The three factors considered include reduction of available area due to habitat destruction for all species in a given area, the risk from the proportional loss of distribution area of each species, and finally the extinction risk of each species given its unique characteristics.

The study considered also the threat to species in three different scenarios of maximum climate change, mid-range climate change and minimum expected climate change.

As an example, 90 percent of the distribution of the bird Boyd’s forest dragon in Queensland in Australia would become climatically unsuitable by 2050 on maximum climate warning scenarios.

The study considers global habitat losses as “currently the most widely recognised extinction threat.” The study looked at areas particularly in Australia, Brazil and South Africa.

The report cautions that “many unknowns remain in projecting extinctions” and that the study does not offer “precise predictions”. It says that “information is not currently available on time lags between climate change and species-level extinctions, but decades might elapse between area reduction and extinction.”

The report warns that “many of the most severe impacts of climate change are likely to stem from interactions between threats, factors not taken into account in our calculations, rather than from climate acting in isolation.”

“The terrifying scientific report highlights the scale and urgency of efforts needed to tackle climate change,” FoEI said in its statement later Thursday.

This must involve urgent action by governments, industry and individuals to reduce their use of fossil fuels such as coal, oil and gas which produce carbon dioxide, the main greenhouse gas.”

Friends of the Earth called for particular action by the United States. “The United States is the world’s largest polluter, but President Bush has refused to sign up to the Kyoto climate treaty, the only international agreement to tackle climate change.”

Not only the natural world but the lives and livelihoods of people across the planet are threatened, says FoEI vice-chairman Tony Juniper. “Governments and businesses are still not taking the issue seriously,” he said. “Householders too have an important role to play.”

The 14 scientists involved in the study were drawn from leading universities and research centres in Britain, Australia, the Netherlands, South Africa, Brazil, the United States and Mexico.