Arthur Chapman, an Australian researcher who has written the only report known to document all of the world's known species, said the extinction threat globally from climate change and other environmental pressures made it more important than ever to know what species existed.

He said a shortage of taxonomists - scientists who identify and classify species - in a number of key fields was slowing the global rate of identifying species.

Mr Chapman's Numbers of Living Species in Australia and the World report was released yesterday by the Environment Minister, Peter Garrett, in Townsville. The report collated existing scientific data and reports from a variety of countries, research bodies and official agencies.

It found that the world now has 1.9 million identified species, while Australia has identified just short of 150,000, just a quarter of all Australian flora and fauna.

It found the best estimates of all plants and animals species are 570,000 in Australia and 11 million worldwide.

Mr Garrett said yesterday that scientific research was alive and well in Australia and that the report showed that over the past three years "we've discovered 48 reptiles, eight frogs, eight mammals, 1184 flowering plants and 904 spiders, mites and scorpions.

"But we have a long way to go - we have discovered and named only about a quarter of Australia's estimated number of flora and fauna. We need this essential information to do a better job of managing our biodiversity against the threats of invasive species, habitat loss and climate change."

Mr Chapman told Fairfax Media that Australia was one of 12 "mega-diverse" countries, and his report showed Australia had a greater rate of endemic species than first thought.

The report found that 90 per cent of mammals and reptiles found in Australia are endemic.

It also found that the 1541 of Australia's species are now listed as threatened with extinction, making up 9 per cent of the all threatened species on the planet. There are 16,956 threatened species globally.

The Greens senator Rachel Siewert said the alarming rates of threatened species in the report highlighted the urgency in protecting "flora and fauna from processes such as land clearing, inappropriate development, disease and feral plants and animals".