Melbourne: In heartening news for environmentalists, the total amount of vegetation globally has increased by almost four billion tonnes of carbon since 2003, according to an analysis of 20 years of satellite data. And this is despite ongoing large-scale deforestation in the tropics.
An Australian-led international team of scientists published the findings in Nature Climate Change, describing a range of causes for the increase.
"The increase in vegetation primarily came from a lucky combination of environmental and economic factors and massive tree-planting projects in China," said lead author Yi Liu from University of New South Wales, Australia.
"Vegetation increased on the savannas in Australia, Africa and South America as a result of increasing rainfall, while in Russia we have seen the re-growth of forests on abandoned farmland.
"China was the only country to intentionally increase its vegetation with tree planting projects," Liu said.
At the same time, massive vegetation loss is still occurring in many other regions.
The greatest declines have been on the edge of the Amazon forests and in the Indonesian provinces of Sumatra and Kalimantan.
"We found unexpectedly large vegetation increases in the savannas of southern Africa and northern Australia.
"The increase in Australia occurred despite ongoing land clearing, urbanization and big droughts across other parts of Australia," said Albert van Dijk of the Australian National University.
The increased greening means that the total amount of carbon captured in Australia's vegetation has increased.
"It's important to recognise that global warming would be happening faster if some of our CO2 emissions were not captured by this vegetation growth," the paper said.
About 50 percent of emissions from human activities stay in the atmosphere even after the other half is removed by terrestrial vegetation and oceans.
The only way to stabilize the climate system is to reduce global fossil fuel emissions to zero, the researchers noted.