17/11/04

Can we halt the loss of biodiversity?

One-third of amphibian species are threatened with extinction according to recent research Copyright: Tim Knights

Send to a friend

The details you provide on this page will not be used to send unsolicited email, and will not be sold to a 3rd party. See privacy policy.

Although scientists value precision, politicians often find it helpful to be vague. When 188 nations, all parties to the 1992 Convention on Biological Diversity (CBD), pledged at The Hague two years ago “to achieve by 2010 a significant reduction of the current rate of biodiversity loss at the global, regional and national level”, the lack of specificity was deliberate. Who could really say what “significant” meant, or be sure of the current rate of loss? And since the language didn’t seem terribly binding, why not sign up?


Few doubt that biodiversity loss is real, or question the urgency of the problem. As a report by the UK Royal Society concluded last year, “the living world is disappearing before our eyes”. Reversing that trend poses daunting scientific, political and economic challenges. Start with the science. What scale of biodiversity is best to consider — global, national, or regional? Should we talk about genetic diversity (some say the best measure) or the number of species? What is a species, anyway? Any of these questions could stir a lively scientific debate, but with 2010 only a few years away, there’s little time for talk.


Jorge Soberón Mainero, a biologist and executive secretary of Mexico’s biodiversity commission Conabio, worries that the sheer magnitude of the problem hinders action. “Biodiversity is a bad word, because it’s too broad,” says Soberón. From his vantage point of trying to implement the CBD goals on a national level, he’d be happy, he says, to “start asking smaller questions”.


Yet for all the doubt and difficulty, Soberón and others point to real, if modest, progress in preserving biodiversity. It’s hard to say how much of that is due to the 2010 target and how much is simply a maturation of the conservation movement, says Thomas Lovejoy of the Heinz Centre in Washington DC, who coined the term ‘biological diversity’ more than 20 years ago. Still, he lauds the CBD’s “serious commitment” to the issue and says that once world bodies set these types of goals, “they tend to deliver them”.


Lovejoy, like most conservation biologists, believes that protecting habitat should take priority while waiting for scientific questions about biodiversity to be resolved. One of the CBD targets for 2010 is to “effectively conserve” at least ten per cent of each of the world’s ecological regions. Protection of most types of habitat, including tropical humid forests, warm deserts, and tropical savannahs, has already surpassed that mark, according to a 2003 United Nations assessment of the world’s protected areas. Lovejoy points to Brazil as a success story. The country is on the way to placing more than 40 per cent of the Brazilian Amazon under some form of protection, which he calls “quite staggering”.


Other regions are making progress as well. The “new big trend” in habitat conservation, says Alain Lambert of the UN Environmental Programme in Nairobi, Kenya, is trans-boundary protection — protected areas based on watershed or ecosystem boundaries rather than national borders. A new Serengeti preserve straddling the borders of Kenya and Tanzania is currently in negotiation, with most of the funding coming from the Frankfurt Zoo in Germany. While such agreements complicate the politics — military concerns must be addressed, for example — the ecological advantages are obvious.


“It doesn’t make sense to protect one side [of an ecosystem],” says Lambert. Other trans-boundary agreements are envisioned for locations including central Asia and the Pantanal wetlands of South America.


While habitat protection advances at a slow but steady pace, the conservation science community is finally coming to agreement on robust ways to measure biodiversity, says Lovejoy. In February, parties to the CBD approved eight ‘indicators’ for immediate testing in the field. These include water quality in aquatic ecosystems, nitrogen deposition (a threat to biodiversity), and levels of assistance to developing nations for biodiversity work.


A scientific committee advising the CBD recently proposed adding five more indicators, including a promising new tool based on the World Conservation Union (IUCN) Red List of threatened species. This ‘Red List Index’ would highlight changes in the endangered status of selected groups of species. The method has already been applied to birds and is now being done for mammals and reptiles (see ‘Red List Index’ will help measure rate of species loss).


Craig Hilton-Taylor, the Red List programme officer, says the IUCN is also working on a less comprehensive index that could be applied to an entire ecosystem, not just a single taxonomic group. The precise methodology is “still very much a work in progress,” says Hilton-Taylor. But the idea is to monitor a representative sample of species to provide a snapshot of what’s happening to biodiversity over a wide region.


Any such indicator is likely to be less than perfect, and important gaps will remain in measuring overall biodiversity, from microbes to the huge number of insect species that haven’t yet been named or even identified, much less monitored. But it’s a beginning. And the consensus among scientists developing methods for measuring biodiversity is to come up with something everyone can use, instead of not doing something just because it is not perfect, says Lovejoy.


Agreeing on a list of indicators and targets at international meetings is one thing, but putting them into practice at the national level is another.


To make a practical start in Mexico, says Soberón, “we don’t need 13 different indicators – we probably need two, or one”. Mexico, for example, does a forest inventory using satellite data backed by ‘ground-truth’ calibration studies every five years. Such monitoring work is expensive, and it needs to be ongoing, he says. Most monitoring efforts in Latin America last only a few years before funding dries up or interest fades. “That’s where we fail,” says Soberón.


Although there are huge differences between countries in terms of technology and numbers of trained scientists, data sharing has improved in recent years, says Simon Stuart of Conservation International’s Centre for Applied Biodiversity Science in Washington DC. Taxonomic databases like the Global Biodiversity Information Facility help, he says, and groups such as UK-based Bionet International’s Global Network for Taxonomy are working to train scientists in the developing world.


Soberón sees ‘citizen science’ also becoming more important in wealthy and cash-strapped nations alike. The US Fish and Wildlife Service, for example, has given a grant to Mexico to teach amateur birdwatchers to do regular bird counts.


Yet money remains a barrier to stemming the loss of biodiversity. Last year’s Royal Society report said flatly, “Without a marked increase in funding, [the 2010 target] … will be unachievable.” Large funding sources like the Global Environment Facility and the World Bank continue steady support for biodiversity protection.

According to Lambert, the exact amounts are getting more difficult to track as biodiversity protection becomes merged into larger environmental programmes — which he takes as a good sign. He says non-governmental organisations like the World Wide Fund for Nature and the Nature Conservancy are doing a better job at pooling their resources through groups like the Conservation Finance Alliance.

Funding at the national level remains inconsistent, however. Many frequently-proposed financial schemes for conservation — bioprospecting, ecotourism, licensing of big game hunts — have been overpromised, and despite isolated successes, have produced “more misses than hits,” says Hilton-Taylor.


Lovejoy sees “no single solution” to funding. Some conservationists have begun to argue that developed nations simply have to pay outright if they want less developed countries to shoulder what often turns out to be the economic burden of conservation (see Conserving biodiversity is a costly ‘business’).


Conservationists also admit that biodiversity has not yet risen to the top rank of world concerns, or even environmental concerns. “The whole thing needs much more political buy-in,” according to Hilton-Taylor. The CBD conferences are good at inspiring delegates, he says. “But when they go back home it’s a different matter. When [individual countries] try to balance budgets, biodiversity comes way down the list.”


So will the world meet its 2010 target?


“I don’t think it was ever achievable, even if they had thrown every possible means at trying to achieve it – it was too big,” says Stuart, who still thinks the goal has been extremely valuable. “It at least got people focused. It’s a learning experience for all of us, the government, the scientists and the conservation organisations.”


Lambert agrees. “It was right to have an over-ambitious goal, because this is what really motivates people to work,” he says. “Now it’s a matter of pushing national governments to step up to the challenge. And if we reach 25 per cent or 30 per cent of the goal, it will be great.”


Link to Royal Society report Measuring Biodiversity for Conservation