Over recent decades, plant growth and vegetation greenness have increased on a global average. This “global greening” is driven by rising levels of carbon dioxide (which acts as a fertilizer) warmer temperatures especially in the North, and intensified land-use and afforestation e.g. in India and China. Although this may sound positive, global greening reflects profound global change with complex consequences. At the same time, in many regions tree mortality increases and crop yields decline due to climate change. The greening itself can be a sign of changing ecosystems functioning, leading for example, to increasing water demand.