Tree restoration potential, Q&A

By Crowther Lab

Our paper on the restoration potential of forests received an overwhelming reaction in the media. We are so delighted for all the wonderful comments and discussion. And the conversation also raised several issues from a few people. These are all important considerations and they are points that we have been well aware of as we conducted the study. We give our brief answers to some of the comments below:

No. To address climate change, we absolutely need both drastic cuts to emissions and significant carbon drawdown. There are thousands of climate change solutions that contribute to both of these, and all of them will be necessary. Our new research only suggests that restoring trees is an extremely powerful drawdown solution, but cuts to emissions are still essential.

This is certainly not the case, and we would never communicate that. Every year, the ocean absorbs about 30% of man-made carbon emissions, and terrestrial ecosystems absorb slightly less. But that means that a large proportion of these emissions enter the atmosphere. Over the years, this has caused the accumulation of ~300 Gt of excess carbon (~1000 Gt CO2) in the atmosphere. Our paper finds that we could capture 205 Gt carbon by adding 0.9 billion hectares of forests – i.e. two-thirds of the total man-made carbon emissions currently in the atmosphere.

We would never encourage the planting of trees in these grassland areas. The sole aim of our study was to find the areas where trees should naturally exist. Our model highlights the areas that we could restore trees to their natural extent. And it also highlights the huge regions around the world that should not support trees, including natural grasslands. 

As Ecologists, we advocate for restoring natural levels of diversity. We support projects that restore a healthy diversity of native species in any location that should naturally support trees.

Indeed, we are not saying this can happen quickly. Restored trees will accumulate carbon slowly over the rest of this century. Like all climate change solutions, this is a long-term vision, which highlights the urgent need for action now.

Ultimately, we are delighted with the immense reaction following the paper, and we hope that it will continue to inspire lots of discussion. Climate change is a huge and complicated topic that will require thousands of solutions. We hope that this new information will encourage people to prioritize restoration amongst those solutions, as it is among our most powerful tool to draw carbon down from the atmosphere at the same time as promoting biodiversity and ecosystem services for humans.