Study shows forests have bigger role in slowing climate change

SINGAPORE,  (Reuters) – The world’s forests can  play an even greater role in fighting climate change than  previously thought, scientists say in the most comprehensive  study yet on how much carbon dioxide forests absorb from the  air.

The study may also boost a U.N.-backed programme that aims  to create a global market in carbon credits from projects that  protect tropical forests. If these forests are locking away more  carbon than thought, such projects could become more valuable.

Trees need large amounts of planet-warming carbon dioxide  (CO2) to grow, locking away the carbon in the trunks and roots.

But scientists have struggled to figure out exactly how much  CO2 forests soak up in different parts of the world and a global  total for how much is released when forests are cut down and  burned.

The study released on Friday in the latest issue of the U.S.  journal Science details for the first time the volumes of CO2  absorbed from the atmosphere by tropical, temperate and boreal  forests. The researchers found that forests soak up more  than 10 percent of carbon dioxide from human activities such as  burning coal, even after taking into account all of the global  emissions from deforestation.

“This analysis puts forests at even a higher level of  importance in regulating atmospheric CO2,” said Pep Canadell,  one of the authors and head of the Global Carbon Project based  at the Commonwealth Scientific and Industrial Research  Organization in Australia.

“If you shut them down, you’re not only losing the carbon  stock into the atmosphere, you’re losing a very active sink  which removes the carbon dioxide,” he told Reuters from  Canberra.
Canadell and an international research team combined data  from forest inventories, models and satellites to construct a  profile of forests as major regulators of atmospheric CO2.

Greenhouse gas emissions from burning fossil fuels and  deforestation are rising rapidly, with growth being largely  driven by surging coal, oil and gas consumption in big  developing nations.

Emissions grew 5.8 percent last year to 33.16 billion  tonnes, as countries rebounded from economic recession, a BP  report said in June. China’s emissions totalled 8.33 billion  tonnes, up 10 percent from the year before.

MAJOR SURPRISE

The researchers found that in total, established forests and  young regrowth forests in the tropics soaked up nearly 15  billion tonnes of CO2, or roughly half the emissions from  industry, transport and other sources.

But the scientists calculated that deforestation emissions  totalled 10.7 billion tonnes, underscoring that the more forests  are preserved the more they can slow the pace of climate change.

A major surprise was the finding that young regrowth forests  in the tropics were far better at soaking up carbon than  thought, absorbing nearly 6 billion tonnes of CO2 — about the  annual greenhouse gas emissions of the United States.

“This is huge and the relevance for REDD is here you have a  huge sink that is bigger than the established tropical forests,”  said Canadell, referring to the U.N.-backed scheme reducing  emissions from deforestation and degradation.

REDD aims to reward poorer nations that preserve their  carbon-rich rainforests with a market-based scheme in which  carbon credits are given for every tonne of carbon locked away.  Many REDD projects currently being developed focus on peat-swamp  forests because these contain the most carbon.

Tropical regrowth forests could represent a new investment  opportunity, Canadell said.

“Unfortunately, some countries have not looked on forest  regrowth as a component of REDD, and so are missing a very  important opportunity to gain even further climate benefits from  the conservation of forests,” he said.

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