Twenty years of satellite data reveals the total amount of vegetation globally has increased by almost the equivalent of 4 billion tons of carbon since 2003. But we’re not out of the woods yet.
Some of us (me) sit around and lament the tragic image of the planet’s forests whacked into nothingness in the name of industry and development. But while massive vegetation loss is indeed happening – notably on the edge of the Amazon forests and in places like the Indonesian provinces of Sumatra and Kalimantan – there are glimmers of hope that all may not be lost.
An Australian-led international team of scientists has developed a new way to map changes in vegetation biomass over time, using satellite measurements of natural radio waves emitted from the Earth’s surface, according to a press release from the Universtiy of New South Wales (UNSW). What they found is heartening: not loss, but a significant increase in vegetation across the globe, according to their data, at least.
“The increase in vegetation primarily came from a lucky combination of environmental and economic factors and massive tree-planting projects in China,” said Dr Yi Liu a lead author from UNSW Australia.
“Vegetation increased on the savannas in Australia, Africa and South America as a result of increasing rainfall, while in Russia and former Soviet republics we have seen the regrowth of forests on abandoned farmland. China was the only country to intentionally increase its vegetation with tree planting projects.”
“Previous analyses of vegetation biomass focused on forest cover change,” said fellow lead author, Professor Albert van Dijk of the Australian National University. “With our approach 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.”
But the only back to pat for the Australian gains is that of Mother Nature. The main cause for the significant growth over the savannas came from higher rainfall over the recent years; in addition, higher levels of CO2 may have helped plants grow more vigorously as well.
But while this is all good news, it's tenuous. Dr. Pep Canadell, a co-author of the study and director of the Global Carbon Project, says that the increases could rapidly reverse.
“This study shows this capture of carbon is very sensitive to year-to-year changes in rainfall over savanna regions, both for Australia and for the global CO2 budget,” he says, and notes the urgency of continuing the trend.
“It’s important to recognize that global warming would be happening faster if some of our CO2 emissions were not captured by this vegetation growth.”