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New study: The global tree restoration potential

Did you know:The restoration of trees remains among the most effective strategies for climate change mitigation. The authors mapped the global potential tree coverage to show that 4.4 billion hectares of canopy cover could exist under the current climate. Excluding existing trees and agricultural and urban areas, they found that there is room for an extra 0.9 billion hectares of canopy cover, which could store 205 gigatonnes of carbon in areas that would naturally support woodlands and forests.

This highlights global tree restoration as our most effective climate change solution to date. However, climate change will alter this potential tree coverage. The authors estimate that if we cannot deviate from the current trajectory, the global potential canopy cover may shrink by ~223 million hectares by 2050, with the vast majority of losses occurring in the tropics. The results highlight the opportunity of climate change mitigation through global tree restoration but also the urgent need for action. ( abstract from the study published in Science ,Vol 365, Issue 6448 05 July 2019, see page 76; see also p. 24)

Many countries already have ambitious goals to plant trees. In Africa, a group of countries have pledged to restore 100 million hectares of forest. In Latin America, countries plan to restore another 20 million hectares. China deployed thousands of soldiers last year to plant trees covering an area roughly the size of Ireland (though that project planted single species, resulting in something that’s more like a tree farm than a real forest). But the new study found that 43% of the countries in the Bonn Challenge, a global effort to restore 350 million hectares of land by 2030, have only committed to restoring half of the land that could be restored.

The new maps will help countries better plan where to plant trees, and what kinds of trees to plant. The interactive version of the data includes suggested species for some areas. As new trees are planted, the next step is equally difficult—helping the seedlings survive and giving communities nearby a reason to keep trees standing rather than eventually chopping them down. Even a startup that is planting trees by drone recognizes that it needs to work closely with local communities for the projects to succeed. “It’s not about planting, it’s about a restoration roadmap where planting is only a little part of it,” says Stolle.

On this new global map, huge swaths of land are dotted in green pixels. These are the areas that could potentially be recovered with forests that have disappeared, according to a new study—and in total, could help capture as much as two-thirds of the carbon that humans have pumped into the atmosphere since the industrial revolution.

Planting trees is far from the only thing that needs to happen to fight climate change. But the study makes clear exactly how much it can help. “Our research shows that it should really be considered to be a top solution that must be prioritized,” says Tom Crowther, a professor of global ecosystem ecology at ETH Zurich and one of the authors of the paper.( Source : Billions of new trees could help stop climate change: Here’s how we get them. A new study found that a massive reforestation effort could be a huge weapon in the climate fight. So where do we put all the trees?)

How trees could save the climate. A tool on the Crowther Lab website ( enables users to look at any point on the globe, and find out how many trees could grow there and how much carbon they would store. It also offers lists of for-est restoration organisations. The Crowther Lab will also be present at this year's Scientifica (web-site available in German only: to show the new tool to visitors.

The Crowther Lab uses nature as a solution to: 1) better allocate resources -- identifying those re-gions which, if restored appropriately, could have the biggest climate impact; 2) set realistic goals -- with measurable targets to maximise the impact of restoration projects; and 3) monitor progress -- to evaluate whether targets are being achieved over time, and take corrective action if necessary.( Source ScienceDaily)