Listing all species on earth 'a possibility'

We've already found more than a million species, but unearthing發掘 the rest was thought to be an impossible task.

But now it seems an army of amateur業餘 scientists have taken up the cause. A new study concludes總結 that, thanks to them, we're in a golden age of discovery, with 20,000 new finds charted繪製 each year.

There could also be far fewer plants and animals left for them to find. The researchers say rather than tens of millions of species living on Earth, there could be between two and eight million.

If the appetite for discovery continues to grow, they say a full ecological生態 audit審計 could be a possibility within the next 100 years.

The scientists also looked at the numbers of species going extinct滅絕的, and said this had been overestimated高估.

Professor Mark Costello, from the University of Auckland, is the lead author of the study:

"Suddenly people say we're in the middle of a mass extinction大滅絕 crisis well that's a bit premature過早的 because when we look at the extinction rates that are actually happening they're not as bad as people have been letting on."

But the International Union for the Conservation of Nature disagreed with the team's conclusion that the rate of new species found was higher than the numbers being lost.

The organisation's deputy director said it was more important to save species than to count them.

http://www.bbc.co.uk/worldservice/learningenglish/language/wordsinthenews/2013/01/130125_witn_listing_all_species.shtml