Critical need for new definitions of forest and forest degradation in global climate change agreements

If global policies intended to promote forest conservation continue to use the definition of forest adopted in 2001 by the United Nations Framework Convention on Climate Change (an area of >0.05-1 ha with >10-30% cover of plants >2-5 m tall at maturity), great quantities of carbon and other environmental values will be lost when natural forests are severely degraded or replaced by plantations but technically remain forests. While a definition of forest that is globally acceptable and appropriate for monitoring using standard remote sensing options will necessarily be based on a small set of easily measured parameters, there are dangers when simple definitions are applied locally. At the very least, we recommend that natural forest be differentiated from plantations and that for defining forest the lower height limit defining trees be set at more than 5 m tall with the minimum cover of trees be set at more than 40%. These changes will help reduce greenhouse gas emissions from what is now termed forest degradation without increasing monitoring costs. Furthermore, these minor changes in the definition of forest will promote the switch from degradation to responsible forest management, which will help mitigate global warming while protecting biodiversity and contributing to sustainable development.