From the United Nations:
The United Nations agricultural agency [FAO] has launched a new database which gathers under one roof previously scattered information about land cover – how much land is covered by croplands, trees, forests, or bare soils – crucial to establishing a good global understanding of the physical characteristics of the Earth’s surface.
The Global Land Cover SHARE database (GLC-SHARE) initiative represents a major and historic improvement: up until now, such data was collected by different countries and organizations which identified, measured and recorded information in diverse, uneven ways.
GLC-SHARE pulled together all that data and submitted it to a thorough quality-control, harmonizing process, using internationally accepted definitions and standards, thereby bringing a wealth of country-level information into one consolidated dataset spanning the entire planet.
Applications of the new GLC-share database include monitoring of global land cover trends, evaluating the suitability of land for various uses, assessing the impact of climate change on food production, and land-use planning.
FAO’s new database reveals the breakdown of eleven global land cover layers: tree-covered areas (27.7 percent), bare soils (15.2 percent), grasslands (13.0 percent), croplands (12.6 percent), snow and glaciers (9.7 percent), shrub-covered areas (9.5 percent), sparse vegetation (7.7 percent), inland water bodies (2.6 percent), herbaceous vegetation (1.3 percent), artificial surfaces (0.6 percent), and mangroves (0.1 percent).