Make Earth observations open access

摘要

Changes in land cover affect the global climate by absorbing and reflecting solar radiation, and by altering fluxes of heat, water vapour, carbon dioxide and other trace gases. Detailed assessments - regional, global, daily and seasonal - of land use and land cover are needed to monitor biodiversity loss and ecosystem dynamics and to aid in reducing emissions from deforestation and forest degradation. Satellite imagery is the best source of such data, especially over large areas. Observations need to be extensive, regular and consistent to establish baselines and trends. But today, most satellite observations have limited coverage and compatibility, because they are controlled by the diverse objectives of national space programmes. In many cases, satellite data are restricted or charged for.