VOA常速英语:New Study Reveals Australian Trees Are Giant Carbon Sponges

After a decade of research analyzing hundreds of sites across the country, scientists have for the first time calculated the importance of natural forests in Australia's fight
against climate change.

They have discovered that the forests can store three times more carbon than previously thought - on average about 640 tons per hectare.

It is estimated that large trees are giant carbon sponges and can store vast amounts of carbon dioxide, the principle greenhouse gas that many researchers believe is the main
cause of global warming.

Trees consume and store carbon dioxide as they grow, which is released into the atmosphere if they are chopped down.

Brendan Mackey is a professor of environmental science at the Australian National University says natural forests are extremely valuable environmental assets.

"We looked at half of Australia's remaining forests and our estimate is that they can store around 33 billion tons of carbon dioxide," Mackey said. "These are very big numbers I know.

If all those forests were to be cleared and all of the carbon in the biomass in the soil were to be released into the atmosphere - that would be the equivalent of about 80 percent of Australia's annual greenhouse gas emissions every year for 100 years. So we really have to protect our natural forests."

Australian researchers believe international decision-makers should pay closer attention to the value of native forests in combating climate change. They have insisted that deforestation around the world has created the same amount of greenhouse pollution as transport.

About half of Australia's forests have been cleared in the past 200 years since the arrival of European settlers.

Scientists have warned that what is left should be protected to allow trees and forests to absorb excess carbon dioxide in the atmosphere and do their bit to tackle climate
change.

Environmental groups have welcomed the latest research and have called on the Australian government to do more to protect the continent's remaining woodlands and forests.

Australia is one of the world's worst per capital emitters of greenhouses gases. Global warming has become a key point of political discussion, although some Australian scientists and farmers believe a changing climate is not due to man's excess but simply the result of shifting natural cycles.