Naudt and co-workers analyze changes in Europe's forests since 1750. Virtually all natural forests have been replaced by forests controlled by man, often with only a few tree species, like Scots pine, Norway spruce or beech. Replacing broad-leaved trees by (darker) pine trees implies that more sunlight is absorbed, leading to net warming. Despite the forest cover having grown by 10% in area since 1750 there was a net release of carbon to the atmosphere of about 3 billion tonnes, due to changes in undergrowth and soil. The authors end their article with the following sentence: "The key question now is whether it is possible to design a forest management strategy that cools the climate and, at the same time, sustains wood production and other ecosystem services.". Read the whole article in Science.