Concern has grown in recent years about deforestation, loss of carbon stored in forests and the role of forests in climate change, increasing interest in forest monitoring and tracking emissions created by deforestation, the United Nations said in a release.

"The need to improve national forest monitoring is overwhelming as the demand for information has never been greater," said Jan Heino, FAO assistant director-general for forestry. "National policy processes are striving to address cross-cutting issues such as poverty alleviation and food security related to forests."

Researchers will carry out a global remote-sensing survey of forests to improve knowledge on land use changes, Heino said. The assessment will include about 9,000 samples and cover all land surfaces on Earth.

"Deforestation continues at an alarming rate of about 13 million hectares annually at the global level," Heino said. "By combining remote-sensing technology with field data collection, we improve the quality of both methods. This provides more accurate information on forest trends and new information on the drivers of deforestation and forest degradation."