Forest area bigger than Canada can be restored

A study by the Global Partnership on Forest Landscape Restoration (GPFLR) - which includes the WWF, Britain's Forestry Commission and International Union for Conservation of Nature (IUCN) - said a billion hectares of former forests, equivalent to six percent of the world's total land area, could be restored. Previous assessments estimated 850 million hectares had restoration potential.

"This is a first go at identifying the total scale of this opportunity. The next stage is to work at a country level to identify what we would restore in the real world," Tim Rollinson, GPFLR chairman and director general of the British Forestry Commission told Reuters in an interview.

Marginal agricultural land, where productivity was low, had the most potential for restoration, the study found.

"There are opportunities in almost every continent. The most potential is in Africa - there are substantial areas in China and India, as well as parts of Brazil," William Jackson, IUCN's deputy director general.

Britain could also do its part. Planting 30,000 football pitches' worth of trees per year could cut its greenhouse gas emissions by 10 percent by 2050, according to a British Forestry Commission report.

It is estimated that 30 percent of global greenhouse gas emissions come from deforestation and agriculture.

World leaders are meeting at a UN climate summit in Copenhagen and there are fears that deforestation and agriculture issues will be at the bottom of a long list of responses to climate change to be discussed.

By 2030, the restoration of degraded forest land could make a 70 gigatonne cut in greenhouse gases - the same as from avoided deforestation - or even twice that amount, based on preliminary estimates in the report.

Investment in mangrove and woodland restoration is worthwhile, achieving rates of return up to 40 percent, a United Nations Environment Programme report said last month.

Forests once covered more than 50 percent of the world's land area. That has declined to less than 30 percent due to unsustainable logging and conversion to other land uses such as grazing, industry, towns and cities, the GPFLR report said.

The rate of deforestation outstrips restoration. The world lost 7 million hectares a year of forests between 2000 and 2005.

"The rate of deforestation has been slowing, but hasn't been going down. Rising agicultural commodity prices and biofuels could drive a new wave. Do you squeeze more productivity out of a hectare of land or do you need more land? - that's the dilemma," Jackson said.