Worldwide forest carbon sources and sinks mapped in unprecedented detail
A new interactive map of carbon sources and sinks from forests around the world confirm that forests take up twice as much carbon as they release. In a new study published in Nature Climate Change Wageningen researchers cooperated with an international team to combine numerous databases with forests measurements on land and from satellite observations. The resulting new zoomable world map reveals forest carbon changes in the last two decades ranging from forest stand scale, the level of communities, provinces, countries to an entire continent.
Forests absorb twice as much carbon as they emit each year.
The forest carbon flux map, now publicly available on Global Forest Watch, shows that between 2001 and 2019, forests emitted an average of 8.1 billion tonnes of carbon dioxide per year from deforestation and other disturbances, while (re)growing forests took up 16 billion tonnes. These substantial amounts of global carbon indicate that forests are net carbon deposits. Forests absorb twice as much carbon as they emit each year, says Prof. Martin Herold of Wageningen University & Research. “But it also means that we cannot miss those sinks in global climate control”. He is referring to the fact that in 2019 alone, the world lost 11.9 million hectares of tree cover: “Healthy forests, soils and oceans help keeping carbon sinks in function. We cannot afford to lose the CO2 absorption capacity of forests”, he adds.
Detailed global maps
The maps show in detail the significant carbon emissions from deforestation in the tropics. For Europe, it demonstrates for instance the effect of forest management in Sweden and Finland where large forest areas are harvested and replanted, or the effect of natural disasters such as the South-West of France where a huge storm destroyed the coastal forests more than a decade ago. In another geographic scale the data show that 27% of the world’s net forest carbon sink falls within protected areas, underscoring the need for conservation within these areas.
Public accessible maps and data
The downloadable underlying data can be used by everyone: regional and national governments, the EU, or environmental NGOs and social organisations. For instance to give a complete picture in the condition and changes of forests in an area. “This information indicates the locations for action. It highlights ‘hot spots’ of forest carbon emission and supports restauration policy and practices for instance to create resilient landscapes as an adaption to climate change. Tree planting means retaining more carbon on land. However, this is just part of the climate solution and it remains essential to invest in reducing fossil fuel carbon emissions,” Martin Herold says.
The methodology was developed by a team of scientists and researchers from CIFOR, NASA Goddard, NASA Jet Propulsion Lab, The Sustainability Consortium, University of Maryland, Wageningen University, Woodwell Climate Research Center and World Resources Institute. By combining ground measurements with satellite observations this method provides the first globally consistent dataset for estimating carbon fluxes from forests. This new monitoring system will support more targeted policies and actions, and transparent tracking towards forest-specific climate mitigation goals with both local detail and global consistency.
The Wageningen contribution by the PhD candidate Daniela Requena Suarez and researcher Sytze de Bruin of the Laboratory of Geo-information Science and Remote Sensing, led by Prof. Martin Herold has been by providing key data sources, and for assessing uncertainties of the database and the estimations combining satellites and ground measurements.