Conservationist warns next big extinction will be man's fault

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Scientist: Next big extinction will be man's fault

By ERIC BERGER

HOUSTON CHRONICLE

Oct. 24, 2010, 8:29AM

Richard Leakey, one of the world's most famous paleoanthropologists and a conservationist, will speak in Houston on Thursday at the Progressive Forum. Leakey, noted for helping to ban ivory trading, has become increasingly outspoken about conservation issues, suggesting human proliferation puts many of the planet's ecosystems and species at risk and warning that we will cause the next great extinction. He spoke with Chronicle science writer Eric Berger.

Q. Do you still feel like humans are close to triggering another great extinction?

A. I'm afraid so. I will talk a little bit about that in Houston. I'm also, at the moment, talking with various colleagues about the possibility of doing a big film like Al Gore's film, An Inconvenient Truth. It would be on this extinction and dealing with the whole human population and what we're just doing to the habitat because of our numbers.

Q. Al Gore's film had a policy objective, capping carbon dioxide emissions. If you were to do a similar film for conservation efforts, what would your policy objective be?

A. It's hard to say because the film isn't written, but waste is an important aspect people can address, wasting of resources. I think also smaller families to address population. I think population size is something we've got to address, and I think people have got to be persuaded this is a serious issue. We have had mega-extinctions before, where 70 to 80 percent of the population has disappeared, and there's no reason to suppose we're not into another one. We're not far away from that number today. We're losing species in numbers that simply aren't sustainable.

Q. How is humanity triggering an extinction?

A. We're reaching a point today where the loss of species today is exceeding the loss of species when the dinosaurs were taken out. This would have catastrophic implications for the loss of life, not necessarily our life, but the life we see on the planet upon which we are dependent for many things — pharmacology, agriculture and things of that kind.

Q. Some people say, "Well what of it? Humans are on top of the food chain, so does it really matter?"

A. I think that's an arrogant viewpoint, and I think it misrepresents what the food chain really is. We are on the top, but the food chain has a long line behind it, and we haven't figured out things at the end of the food chain, like bacteria and viruses and what they could do if stimulated or if the food chain is shaken up. I think we ought to be a little more reasoned in our consideration of these things.

Q. In the last decade there's been a lot of talk about climate change. Has that message swamped the conservation message, or can the two issues work together?

A. Well I think they're very much two parts of the same thing, and I think maybe the conservation message was prematurely presented on its own and maybe should have been presented as part of a bigger picture. Without habitat conservation, without recognizing the importance of water and ecosystems, no amount of good effort except putting animals behind bars is going to help.

Q. Can you give me an example or two of conservation issues that really trouble you?

A. Look at the fish stocks. We've basically cleaned out the sea, in relation to commercial species and numbers that would make them commercially viable. In inland waterways we've poisoned them with mercury and other things to the point where we can't eat them. I think we're setting up for a fall with our constant use of antibiotics and antiviral medicines for plants and animals. Sooner or later something's going to get a resistance, and you could wipe out the chickens of the world. Or you could wipe out wheat or rice. Then you're not talking about the United States, you're talking about the globe with 6 or 7 billion people.

Q. Are there any hopeful signs out there in conservation of species or nature?

A. I think minor efforts show that some species can be brought back from the brink. We have certainly, in my lifetime, seen great improvements to environmental management in big cities, particularly in developed countries. But as you know, it's not just the developed countries we have to worry about, and that's the hard message to sell.

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