By Alex Kirby BBC News Online environment correspondent

A hugely ambitious project to find and name every species on Earth within the next 25 years has been launched by scientists.

The internet and the development of DNA sequencing technology make the goal achievable, they say.

This should create "a one-stop shop" of data which both amateur and professional naturalists can use.

The first rule of intelligent tinkering is to keep all the pieces Lord May

The task is urgent, because of the rate at which species are vanishing into oblivion before their existence has been recorded.

Professor David Hillis, of the University of Texas, US, says about 1.7 million species have been described so far, although estimates of the total number range from 10 million to 100 million.

He told BBC Radio 4's environment programme Costing the Earth: "Many fields of biology suffer from our lack of knowledge.

Galloping losses

"We're very bad at making predictions about ecological systems, for instance, because we know so little of the species interactions - because we know so few of the species.

"Yet each is a novel solution for how an organism survives in the world. So there's a genetic goldmine of information within every species.

"We can't protect things we don't know about. The biomedical implications are enormous."

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Lord May is president of the UK's national academy of sciences, the Royal Society.

He told the programme: "Extinction rates have accelerated by about a thousandfold over the average that's been seen over the roughly 600 million year sweep of the fossil record.

"There are various further lines of evidence that point to further acceleration by a factor of perhaps 10 over the coming century.

"We are today standing on the breaking tip of the sixth great wave of extinction in the history of life on Earth, different from the others in that it's unambiguously associated with us.

"The first rule of intelligent tinkering is to keep all the pieces. Do you want to live in a grievously impoverished world, the world of the cult movie Bladerunner?"

Harnessing technology

Professor John Lawton, who heads the UK's Natural Environment Research Council (Nerc), says without taxonomy the whole of modern biology would be impossible.

He told Costing the Earth: "Imagine having a library in which you didn't know where any of the books were, and you didn't know what their titles were, and then trying to find the right book."

About 1.5 million species have been identified so far, with a further 10,000 or so added annually.

Lord May said: "At that rate it's going to take us about 500 years just to complete the catalogue, leaving aside the fact that extinctions might help us by wiping a lot of them out, which is hardly a cheerful solution."

In the field: David Hillis

Professor Hillis is one of the scientists involved in the All Species Foundation, which aims to find every unknown species on Earth within the next 25 years.

He says the task is as visionary as the Moon landings and the discovery of the human genome. But he thinks it can be done.

The secret, the Foundation says, lies in combining the power of the internet with the development of DNA sequencing.

Closing the loop

Instead of the time-consuming present system of comparing new discoveries with museum species, there will be a worldwide web-based database.

DNA information can be quickly submitted and examined to see whether it is related to known organisms, or is from a genuinely new species.

One example of the sort of new discovery the Foundation is looking for is the Austin blind salamander, which lives in natural pools in the city of Austin, Texas.

People have swum there for years. But it was only in 2002 that the Austin blind was found and identified as a new species.

Salamander images copyright and courtesy of Dee-Ann Chamberlain