Mere afforestation is not the answer to stop global warming: Study

London, June 20: The United Nations (UN) is failing to accurately measure the global climate benefits of preserving forests, with reports suggesting that it has failed to take into account the fact that forests also alter temperature in other ways.

The UN had set up the REDD programme (Reducing Emissions from Deforestation and Forest Degradation) in 2008 with an intention at provide shelter to many species, and tore carbon dioxide that would otherwise warm the planet.

But what it failed to assess is that forests also alter temperature in other ways, as those close to the poles are dark, and therefore absorb more sunlight than croplands would, the New Scientist reports.

However, in the tropics, more water evaporates from forests than from unforested land, so they cool their surroundings.

Research conducted by Vivek Arora of Environment Canada and the University of Victoria, British Columbia, and Alvaro Montenegro of St Francis Xavier University in Antigonish, Nova Scotia, Canada, has indicated that while the overall effect of forests is small, it is not so in all the cases.

They found that a given area of tropical forest is around three times as effective at reducing warming as the same area of high-latitude forest because tropical forests are much better at cooling their surroundings by increasing the evaporation of water than that of higher latitude forests, as they absorb so much sunlight.

Yet REDD assesses forests solely on the amount of carbon they trap, largely because measuring changes to evaporation and reflectivity is difficult, the report said.

"The carbon metric undervalues tropical forests. We have to consider the other effects of land cover change," Richard Betts of the Met Office in Exeter, UK, said.

Copyright Asian News International/