Trending Science: Plant a trillion trees to save the planet, study urges

According to findings in the journal ‘Science’, we can mitigate climate change by planting lots of trees. A trillion of them in fact, maybe even more.

Swiss scientists indicate this unprecedented, large-scale tree planting will help to capture a huge amount of CO2. They calculated that over several decades these new trees could suck up almost 750 billion t of heat-trapping CO2 from the atmosphere. That’s nearly as much carbon pollution as humans have emitted in the last 25 years.

Going on a tree-planting binge around the world

Is there enough space to cover such massive reforestation? The team of scientists reveal the trees could be planted without encroaching on farmland or urban areas. Even with existing cities and farmland, there’s enough space for new trees to cover 9 million km2. They identified Russia (151 million ha), the United States (103), Canada (78), Australia (58), Brazil (50) and China (40) as having the most room for new trees.

“Our study shows clearly that forest restoration is the best climate change solution available today and it provides hard evidence to justify investment,” senior study author Prof. Thomas Crowther, a climate change ecologist at the Swiss Federal Institute of Technology (ETH Zürich), told the ‘BBC’. “If we act now, this could cut carbon dioxide in the atmosphere by up to 25%, to levels last seen almost a century ago.”

“It will take decades for new forests to mature and achieve this potential,” he said. “It is vitally important that we protect the forests that exist today, pursue other climate solutions, and continue to phase out fossil fuels from our economies.”

Tree planting is the most feasible and sustainable solution

“This new quantitative evaluation shows [forest] restoration isn’t just one of our climate change solutions, it is overwhelmingly the top one,” Prof. Crowther told the British newspaper ‘The Guardian’. “What blows my mind is the scale. I thought restoration would be in the top 10, but it is overwhelmingly more powerful than all of the other climate change solutions proposed.”

Tree planting is “a climate change solution that doesn’t require President Trump to immediately start believing in climate change, or scientists to come up with technological solutions to draw carbon dioxide out of the atmosphere,” he added. “It is available now, it is the cheapest one possible and every one of us can get involved.”

Lead author Jean-François Bastin, also at ETH Zürich, said action is immediately needed: “Governments must now factor [tree restoration] into their national strategies.”

Christiana Figueres, a former UN climate chief who played a key role in delivering the Paris climate agreement in 2015, embraced the new study: “Finally we have an authoritative assessment of how much land we can and should cover with trees without impinging on food production or living areas. This is [a] hugely important blueprint for governments and private sector.”

With the climate changing so quickly and shrinking this available space, it now becomes a race against time to restore so much forest in the next few decades.