Massive tree planting has potential to tackle climate crisis

The planting of billions of trees across the world would be the biggest and cheapest way to tackle the climate crisis, according to scientific analysis.

New research estimates that a worldwide planting program could remove two-thirds of all the emissions that have been pumped into the atmosphere by human activities, a figure the scientists describe as “mind-blowing”.

As trees grow, they absorb and store the carbon dioxide emissions that are driving global heating.

The analysis found there are 1.7 billion hectares of treeless land on which 1.2 trillion native tree saplings would naturally grow. That area is about 11% of all land and equivalent to the size of the US and China combined. Tropical areas could have 100% tree cover, while others would be more sparsely covered, meaning that on average about half the area would be under tree canopy.

As reported by the Guardian, the scientists specifically excluded all fields used to grow crops and urban areas from their analysis. However, they did include grazing land, on which the researchers say a few trees can also benefit sheep and cattle.

Professor Tom Crowther at the Swiss university ETH Zürich, who led the research, advised “this new quantitative evaluation shows (forest) restoration isn’t just one of our climate change solutions, it is overwhelmingly the top one.

“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.”

Professor Crowther emphasised that it remains vital to reverse the current trends of rising greenhouse gas emissions from fossil fuel burning and forest destruction, and bring them down to zero. He said this is needed to stop the climate crisis becoming even worse and because the forest restoration envisaged would take 50-100 years to have its full effect of removing 200bn tonnes of carbon.

Other scientists agree that carbon will need to be removed from the atmosphere to avoid catastrophic climate impacts and have warned that technological solutions will not work on the vast scale needed.

Jean-François Bastin, also at ETH Zürich, said action was urgently required, commented “Governments must now factor (tree restoration) into their national strategies.”

Welcoming the review, Christiana Figueres, former Executive Secretary of the UN Framework Convention on Climate Change and founder of the Global Optimism group, stated “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 hugely important blueprint for governments and private sector.”

Tree planting initiatives already exist, including the Bonn Challenge, backed by 48 nations, aimed at restoring 350 million hectares of forest by 2030. However, the study shows that many of these countries have committed to restore less than half the area that could support new forests.

Earlier research by Professor Crowther’s team calculated that there are currently about 3 trillion trees in the world, which is about half the number that existed before the rise of human civilisation.

Images courtesy of National Tree Day.