About half the carbon stored in terrestrial vegetation is stored in tropical forests. This store of carbon is of great importance to our climate as it undergoes significant losses and gains. Deforestation results in carbon being released to the atmosphere, with tropical deforestation currently accounting for about 12% of human-derived greenhouse gas emissions. In contrast, undisturbed tropical forests actively remove carbon dioxide from the atmosphere: in response to increased carbon dioxide concentrations in the atmosphere tropical forests are increasing in biomass by about 1 % per year, leading to a total sink similar in magnitude to the source from tropical land-use change.
Mapping the distribution of these carbon stocks enables us to calculate carbon losses following deforestation, predict future losses from deforestation, and model future climate trends. It also gives us a better understanding of the ecology of these forests and how long tropical forests can carry on absorbing carbon from the atmosphere. Accurate carbon maps are also important for the recent flurry of projects that aim to preserve forests from imminent deforestation (Reducing Emissions from Deforestation and forest Degradation, or REDD+ projects). About 200 small-scale REDD+ projects are in some-stage of development in the tropics, with country-level projects expected to form a key part of a post-2015 UN climate deal.
A number of maps of the carbon stocks held in tropical vegetation have therefore recently been released. These maps differ greatly in resolution, projection, scale, and units, and obtaining the raw data upon which the maps are based is often difficult. This makes it hard for interested parties to easily access and compare the maps. Therefore Ecometrica, in partnership with Dr Edward Mitchard from the University of Edinburgh, have made a Global Carbon Map comparison app (more information is available here) on Ecometrica’s innovative Our Ecosystem platform. This web tool allows different tropical carbon maps to be compared on the same scale, and the total carbon contained in a user-supplied area of interest displayed and downloaded as a pdf report. Currently two maps are available (both extending across the whole tropical region and dated mid-2000s), and we hope to be able to increase this soon. We expect this app to become an invaluable resource for conservation projects, REDD+ projects, forestry departments, and interested scientists, conservations and the general public.