It processed more than 650,000 Landsat 7 satellite images from between 1999 and 2012 using Google Earth Engine. The resulting maps enabled changes in forest and other land cover to be quantified.
The maps showed that 2.3 million square kilometres of forest was lost between 2000 and 2012, and only 800,000 square kilometres gained. Paraguay, Malaysia and Cambodia had the highest rates of forest loss, with Paraguay having the highest ratio of forest loss to gain. Brazil showed the largest decline in annual forest loss, which halved from a high of about 40,000 square kilometres in 2003–04 to 20,000 square kilometres in 2010–11.
‘Brazil used Landsat data to document its deforestation trends, then used this information in its policy formulation and implementation. They also shared these data, allowing others to assess and confirm their success,’ said lead author Matthew Hansen. ‘Such data have not been generically available for other parts of the world. Now, with our global mapping of forest changes every nation has access to this kind of information, for their own country and the rest of the world.’
This story was published in the January 2014 edition of Geographical Magazine