Azerbaijan National Academy of Sciences

A new study has found, somewhat counter intuitively, that more trees might not always mean a cooler planet. In fact, researchers examining 260 years of changes in European forest management found that—despite a 10% increase in wooded land—the continent’s forests have actually caused a slight increase in regional temperatures since 1750.

The new findings show that simply planting trees—at least in temperate areas—isn’t enough to stave off global warming. Researchers from the Laboratory of Climate Science and Environment in Gif-sur-Yvette, France, came to this conclusion by building a model that uses 260 years of forestry data in Europe, from the distribution of tree species to the methods people have used to harvest wood. From 1750 to 2010, the continent added almost 200,000 square kilometers of forest, and created a 0.12°C rise in temperature.

But there is already an understanding among researchers that carbon sinks—areas that sequester carbon—interact with the atmosphere in complex ways, not all of them positive for climate change.

Scientists are asked to be attentive to what kind of trees are planted and not take the landing of the forest as a panacea for global warming.

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