More than a billion hectares of land around the world has potential for forest restoration, according to a new study.

The Global Partnership on Forest Restoration (GPFLR) report, released in London, says an area bigger than the size of Canada (997 million ha) can be restored to forestland. A previous estimate was 850 million ha.

“The earth’s forests continue to shrink, and what’s left is increasingly being degraded,” said Tim Rollinson, chairman of GPFLR and director-general of the Forestry Commission.

“We know how to restore forests and make them sustainable. We also know where we should do it, so we should be getting on with it.”

GPFLR partners, including the Forestry Commission, said forest restoration action should be taken hand in hand with efforts to halt forest loss and degradation.

Preliminary analysis indicates that by 2020 restoration of degraded forests could make the same contribution to reduction of greenhouse gases as that which could be expected from avoided deforestation and perhaps twice as much.

GPFLR will work with countries over the next year to clarify these figures on a country-by-country basis.