Last year, the journal Science published a study that made a bold - and elegantly simple - claim: To mitigate climate change, plant a trillion new trees.
Authored by a team of scientists from various research institutions in Europe and the Food and Agriculture Organization of the United Nations, the study attracted considerable mainstream media coverage.
Soon after, tree-planting initiatives across the globe bloomed. Ethiopia announced it would plant 350 million trees in a single day and India promised to plant 220 million. The US unveiled a plan to establish forests in Asian and African cities. Companies ranging from Biocarbon Engineering to EasyJet to Warner Music turned the spotlights on their tree-planting initiatives.
The excitement was understandable. The idea that we could negate the effects of centuries of deforestation and keep the planet cool enough to survive simply by planting some trees sounded really good.
The study found that a trillion new trees could store 205 billion metric tonnes of carbon - the equivalent of 25 percent of the current atmospheric carbon pool and enough to help keep us under a 1.5-degree Celsius global temperature rise. Climate action, meet your magic bullet.
Yes, we need to plant trees. Close to one billion hectares (2.5 billion acres) globally is estimated to be available for some kind of forest restoration. If only it were that simple.
To succeed in the fight against climate change we have to do two big things: Stop emitting carbon dioxide and remove the excess carbon dioxide we have already emitted. Restoring forests is the best way to do that second part - but not all restoration is created equal.