Accessibility links

World: Global Warming Could Lead To Extinction Of Plant, Animal Species

  • Don Hill

An international group of biologists says that global warming threatens to set as many as a million species of Earth's plants and animals on the road to extinction.

Prague, 8 January 2004 (RFE/RL) -- A group of scientists, led by Professor Chris Thomas at Britain's University of Leeds, have completed the largest-ever study of its kind and published its findings in the current issue of the British-based scientific journal "Nature."

Applying classical ecological principles in possibly controversial new ways, the group's findings substantiate some of the direst forecasts of threats to the earth's environment from greenhouse gases and other man-made pollutants.

But lead author Thomas hedges the findings with scientific caveats that contradict some news reports and political reactions.

"What we found is that if we project which parts of the world are going to be suitable for species of animals and plants in the future, then we find that for a lot of species there aren't going to be any suitable climatic areas left for them, and many others will be much reduced in their distribution."

The study, as Thomas puts it, does "not quite" conclude, as some news services report, that global warming could wipe out a quarter of all species of plants and animals on Earth by 2050. What it does say is that somewhere between 10 percent and 50 percent of the 1,000 species studied would be either extinct or on their way to extinction by mid-century.

"So they might be declining each generation," he says. "And so over the following decades or even centuries, they would be gradually pegging out (dying) one by one. That, of course, opens a sort of glimmer of hope -- because if we can reverse the climatic warming that is taking place so that the environment becomes suitable for these species again in future, some of them may be rescued by returning the climate to what it was before the last individuals actually die."

Klaus Toepfer, director of the UN Environment Program, one of the world organization's specialist agencies, seized upon the report's findings to call for enforcement of the Kyoto Protocol.

In December 1997, more than 160 nations met in Kyoto, Japan, to negotiate binding limitations on greenhouse gas emissions by developed nations, along the lines of a UN Framework Convention on Climate Change drafted five years earlier. The outcome of the meeting was the Kyoto Protocol, under which developed nations agreed to limit their greenhouse gas emissions.

The United States, for example, agreed to reduce emissions from 1990 levels by 7 percent during the period 2008-2012. The protocol stipulates that it can come into force only when countries responsible for 55 percent of the world's emissions of carbon dioxide approve it. It appears doomed because the United States, representing 36 percent, and Russia, representing 17 percent, have refused to ratify it.

Reuters news service quotes Toepfer as saying of the Thomas study, "This alarming report underlines again to the world the importance of bringing into force the Kyoto Protocol."

Thomas says the difficulty in implementing the protocol may bode ill for passing even more stringent environmental measures in the future.

"We didn't specifically look at the impact of the Kyoto Protocol, but it has to be said that the protocol is only having a relatively minor effect, probably, on the amount of warming that we see. It's a start, and the problem is that it's been so controversial to get even that very limited first step in the direction of real control -- it is so difficult to get even that ratified -- that one suspects that things are going to get quite a lot worse before they get better."

"Nature," the journal that published the Thomas group's findings, is peer-reviewed, meaning that papers are submitted to other experts for review, comment, and criticism before publication. Thomas readily concedes that his group's paper does not so much establish new truths as point the way to additional, more conclusive investigation.

The paper's predictions of species dying out are based on what is known of the environments the species now inhabit. It assumes that if such environments cease to exist or are reduced to insignificant areas, the plants and animals they now harbor likewise will cease to exist.

Thomas says that's part of the "glimmer of hope" he referred to.

"Well, we still don't know what the time scales are between the climate's becoming unsuitable for something and the last individual's dying out. And so that's an important new area for research -- and until that's known, we don't really know how bright this glimmer is."

He says also that in a number of places, "we're developing new methods on how to assess the extinction risk to species."

Thomas says that although the study does not pin down a specific time frame or assured results, its overall conclusions are valid and disturbing.

"Whilst there are a lot of doubts in this study about exact proportions of species that might become extinct, what is very clear is that climate change should now be considered to rank alongside habitat loss and the other great threats to global biodiversity and should be taken very, very seriously by all conservation organizations, be they within countries or at an international scale."

He says that if one extends to all species on Earth the study's conclusions based on the 1,000 species it considers, the possibility is that a million species are at risk in the coming century. He says that suggests a biological disaster that would rival the extinction of the dinosaurs 65 million years ago.