Research
The vegetation covering the continents has decisive influence on climate, exchanging heat, moisture, momentum, and a variety of chemical materials with the atmosphere. Humans are substantially interfering with this exchange, having transformed three quarter of the ice-free land surface to managed lands, with severe effects on the Earth system; e.g., one quarter of current anthropogenic greenhouse gas emissions arise from land use. Effects are expected to become even stronger in the future, as demand for food and fibre rises in a more populous and affluent world, and as the international goal of limiting global warming to two degrees may rely on substantial additional CO2 sinks through land use.