Adding 1 billion hectares of forests could help limit global warming to 2.7 degrees Fahrenheit by 2050, according to the United Nation's Intergovernmental Panel on Climate Change, but if current trends continue, the planet could see that temperature increase by 2030.
Swiss researchers wanted to see of if there's enough room on Earth with existing farmland and cities to support that many extra trees. They reported in Thursday's edition of the journal Science that there's enough space to cover 3.5 million square miles, about the size of the United States.
Those added trees could capture 205 gigatons of carbon in the future, about five times the amount of carbon emitted in 2018, according to Science magazine.
“This work captures the magnitude of what forests can do for us,” ecologist Greg Asner, of Arizona State University in Tempe, who was not involved in the research, said. “They need to play a role if humanity is going to achieve our climate mitigation goals.”
Credit: J. Bastin
Credit: J. Bastin
The study by the Swiss Federal Institute of Technology determined that the planet could see a difference almost immediately because young trees remove more carbon from the atmosphere than older ones. They also determined the tropics would see the greatest benefit from such a worldwide mass planting.
"This is by far — by thousands of times — the cheapest climate change solution and the most effective," study co-author and climate ecologist Thomas Crowther said.
The researchers used satellite images of Earth to determine which areas could support more trees, leaving out agriculture and urban areas. Lead author Jean-Francois Bastin estimated there’s room for possibly as many as 1.5 trillion trees.
"We all knew restoring forests could play a part in tackling climate change, but we had no scientific understanding of what impact this could make," Crowther said. "Our study shows clearly that forest restoration is the best climate change solution available today."
The countries with the most room for new trees include the U.S., Canada, Brazil, Russia, China and Australia.
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