For many years it has been asserted that forests are our great allies in mitigating climate change due to their ability to sequester carbon. However, putting all the responsibility on them, trusting that the trees will ‘do their job’ while we continue to emit greenhouse gases into the atmosphere is not the solution , and numerous studies have already been commissioned to demonstrate this.
For example, a work published in the journal Global Change Biology in March 2019 provided different reasons why reforestations are not the best or fastest solution to curb climate change. Although these are tools necessary to help mitigate the problem and that will serve in the long term, we do not have time and what we have to do is stop the burning of fossil fuels, as another study published in Earth ‘s Future also stated in 2017.
Apart from other management problems, one of the biggest drawbacks of the tree planting strategy is the available space: how many trees can we plant – and where – without occupying, for example, the urban and agricultural areas necessary for our subsistence?
Well, a team from the Crowther Laboratory for Global Ecology of Ecosystems at the ETH University of Zurich (Switzerland), has published a pioneering work that calculates where in the world new trees could grow and how much carbon they would store.
Reforest an area equivalent to the size of the US
The researchers calculated that, under current climatic conditions, there could be 4.4 billion hectares of continuous tree cover on our planet, compared to 2.8 billion today. Therefore, there would be a capacity for 1.6 billion more hectares of forest.
Of these 1,600 million hectares, 900 million meet the previous criterion of not being an occupied surface for human activities. We are talking about an area equivalent to the size of the United States that would therefore be available for forest restoration. Once mature (remember that this is not a short-term solution), these new forests could store 205 billion tons of carbon: roughly two-thirds of the 300 billion tons of carbon that have been released into the atmosphere as a result of human activity since the Industrial Revolution.
And where do we plant trees?
On the other hand, the study shows which parts of the world are best suited for forest restoration. The greatest potential can be found in just six countries: Russia, the United States, Canada, Brazil and China.
The Crowther Laboratory offers on its website a very intuitive tool that allows you to navigate the map and discover how many trees could grow in each place and how much carbon they would be able to accumulate.
“We all knew that forest restoration could play a role in the fight against climate change, but until now no one had calculated its potential impact,” explained Jean-François Bastin, lead author of the work. “Our study shows that forest restoration is a good solution, but we must act quickly, since new forests will take decades to mature and reach their full potential as a source of natural carbon storage, ” the researcher explains.
A very complex problem
Climate change is a very complex problem and therefore solutions will never be simple. Contrary to what happened with the hole in the ozone layer, which had a very specific source – certain compounds among which CFCs stand out – and a direct solution – stop emitting CFCs – the environmental challenge we face now it has different dimensions, starting because the main cause (greenhouse gas emissions) are involved in many aspects of our lives.
All strategies to mitigate climate change, some more effective than others, will be welcomed but, as the disseminator and expert Andreu Escrivá, author of the book ‘It is not late’, warns, we are facing a challenge that is also social and economic (it affects to our way of living and consuming), and it is not enough to rely on a technological solution that solves the problem.
Reference: Bastin et al. 2019 The global tree restoration potential, Global Change Biology doi: 10.1126 / science.aax0848
