When it comes to tackling climate change, planting trees seems like a pretty superficial solution. Surely planting a few trees isn’t enough to reverse the decades of abuse we’ve put our planet through?
As it turns out, it could well be enough.
Research published in Science this month found that there is 0.9 billion hectares of land available across the globe, which could be used as forests, planting over 500 billion additional trees.
As trees grow they photosynthesize carbon dioxide and water, turning it into glucose and oxygen. This means that they’re very effective at removing carbon dioxide from the earth’s atmosphere. Those 500 billion extra trees could store up to 205 gigatons of carbon, which would reduce the carbon in the atmosphere by around 25%.
“Excluding existing trees and agricultural and urban areas, we 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.”
To determine this, the researchers looked at existing tree cover using 80,000 images taken from Google Earth. They then used artificial intelligence to combine this data with known factors for growing trees including soil, topography, and climate. This allowed them to create a global map of the areas in which trees could successfully grow.
They found that around two-thirds of all land on the planet (8.7 billion hectares) was capable of growing forest. Without impinging on land for agricultural use or human activity, the planet could easily support an extra 0.9 billion hectares of forest. This would mean around 500 billion extra trees, which could absorb 205 gigatons of carbon once fully grown — roughly 5 times the amount of carbon emitted globally in 2018.
Is planting trees really enough to stop climate change?
So this all sounds excellent, but is solving climate change really as simple as planting these additional trees?
As it stands, we’re cutting down around 10 billion more trees every year than we’re planting. As trees store carbon dioxide, this means we’re releasing carbon into the atmosphere through chopping down trees.
This is because land is economically valuable. The majority of deforestation is down to the agricultural industry. Animal agriculture is incredibly land intensive, requiring land both for grazing cattle and keeping animals, and for growing feed for them. Of course, trees are also a valuable source in themselves, and are also chopped down for timber, manufacturing, and paper production.
In order for trees to be a viable solution for global warming, we’d need to stop chopping them down at a faster rate than we’re growing them. And with this, it quickly becomes an issue of politics and economics. The researchers identified particular areas across the globe where forest could be grown. This includes 151 million hectares in Russia, 103 million hectares in the United States, 78.8 million hectares in Canada, 58 million hectares in Australia, 49.7 million hectares in Brazil and 40.2 million hectares in China.
For their research to become reality, we’d be reliant on the governments in these countries committing to a) using these areas of land for forestry and b) not undertaking deforestation elsewhere. Deforestation of the Amazon rainsforest in Brazil, one of the countries cited here, rose 88% in 2019, and we know their right-wing president Jair Bolsonaro has no intentions of slowing this.
Another of the countries mentioned is Russia, a country whose primary income is from oil and gas. It’s also one of the lowest ranking countries in terms of the environmental awareness of its people, with ‘ecology and environment’ coming 15th among concerns of Russian voters in a poll conducted in May 2019.
There’s also a finite amount of land on our planet. If we were to use that extra 0.9 billion hectares of land to plant trees then once it’s gone, it’s gone. These trees would help to reduce the amount of carbon in our atmosphere, but they wouldn’t stop human activity producing more carbon to replace that.
“The best solution to climate change remains leaving fossil fuels in the ground.” — Simon Lewis, UCL researcher
Planting trees is important. Rainforests contain 50% of our known wildlife species, on just 6% of our land. Trees are vital for wildlife habitats and biodiversity. They’re also vital in urban areas, where shade from trees cools cities and reduces air pollution on our streets. Trees are known to improve our wellbeing, with research showing that spending time in nature will significantly improve people’s health.
But whilst these things are important, I don’t think we can rely on trees to solve our climate problems. Reforestation doesn’t address the root cause of our problem: our shared human reliance on fossil fuels. Planting trees isn’t the answer to solving climate change, but it is a crucial part of the solution.
What can I do to help?
If you want to get involved with planting trees to mitigate climate change, then there are some brilliant organisations and projects out there to support with your time or money.
- Ecosia is a search engine which uses advertising money to plant trees .
- The Woodland Trust is the UK’s leading woodland conservation charity, and is aiming to plant 64 million trees in the next 10 years. As part of this, it gives away thousands of trees for free to schools and communities.
- The Great Green Wall is an African-led movement aiming to grow a 8000km natural wall across the entire width of Africa.
- The Bonn Challenge is a global effort to bring 150 million hectares of the world’s deforested and degraded land into restoration by 2020, and 350 million hectares by 2030. It was launched in 2011 by the Government of Germany and IUCN, and later endorsed and extended by the New York Declaration on Forests at the 2014 UN Climate Summit.