China last month donated to the United Nations the first open-access, high-resolution map of Earth's land cover, as a contribution towards global sustainable development and combating climate change.

The map, known as GlobeLand30, comprises data sets collected at 30-metre resolution — more than ten times that of previous data sets. These data sets will be valuable for monitoring environmental changes and for resource management at global, regional and local scales (see also M. A. Wulder and N. C. Coops Nature 513, 30–31; 2014).

The GlobeLand30 data sets are freely available and comprise ten types of land cover, including forests, artificial surfaces and wetlands, for the years 2000 and 2010. They were extracted from more than 20,000 Landsat and Chinese HJ-1 satellite images (see www.globallandcover.com).

GlobeLand30 will promote scientific data sharing in the fields of Earth observation and geospatial sciences.