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One of the most effective tools the world has against climate change is trees. And immediate action is in need to protect trees and plant new ones as China has been doing, said analysts.
Trees absorb enormous amounts of greenhouse gases. The potential impact of more trees on climate change has been brought to the fore after a new study suggested that planting 1 trillion trees around the world would be "the cheapest climate change solution".
Nonetheless, any serious effort to address climate change would also require significant curbs on emissions, experts emphasize.
Thomas Crowther is a professor at ETH Zurich University and the lead researcher of the study published on July 5 in the journal Science. He estimated that planting or restoring 1 trillion trees would cost the world about $300 billion, about half of the combined sales of Apple, Microsoft and Amazon last year. It would be equivalent to about 2.2 percent of a single year of China's economic output.
Over a few decades, that many trees could extract 750 billion metric tons of carbon dioxide from the atmosphere - about as much as people have generated over the past quarter-century. The study includes potential sites for tree planting, and estimates the area needed would be roughly equal to the landmass of the United States.
The United Nation's Intergovernmental Panel on Climate Change also estimated that planting trees on 1 billion hectares of land (roughly the same amount as the total suggested in the study) would prevent average temperatures from rising by 1.5 C by 2050.
"Trees are humans' best defense against climate change," Mei Ng, chairperson of green group Friends of the Earth(HK), told China Daily. "Tree planting is undeniably the simplest and most effective solution to mitigate ecological risks and climate threats." Friends of the Earth is an international network of nongovernmental organizations.
Ng said a campaign to plant all those trees would require a three-pronged approach.
The first prong would be to protect and enhance existing forests and green space.
The second prong would be to plant new trees while regenerating forests and green space. This could be done through "regenerative development" to replenish any resources used.
The third prong is public participation. "We need more knowledgeable and well-trained manpower to ensure we plant the right trees, at the right place, at the right time, and maintained by the right people," said Ng.
Innovative efforts
Already, of course, there are many innovative efforts underway around the world, and particularly in China and Asia, for planting trees and protecting existing ones.
For instance, Friends of the Earth(HK) has undertaken a project to plant 230,000 trees at the head of the Dongjiang River in Jiangxi province, East China.
That project pales in comparison with a 6.66 million hectares of new forest that China set out to plant last year by deploying 60,000 soldiers to plant trees.
Between 2016 and 2020, China plans to increase the land area covered by woodlands from 21.7 percent to 23 percent. Between 1990 and 2015, China added almost half a billion square kilometers of forest cover, according to the World Bank.
Still, there are those who question the global push to plant more trees - on the basis of time available.
"The climate crisis represents an emergency and there is no time to wait for this tree-growing program to come to fruition," Harald Heubaum, a climate policy expert at the University of London and cofounder of sustainable finance data initiative SUFINDA C.I.C., said.
"It's actually more important to protect mature forests which store huge amounts of carbon today from getting logged than to rely on planting new forests which will take a long time to grow," Heubaum said.
Ultimately, planting all those trees would not, by itself, be enough to reverse climate change. Even the authors of the study point out that such a push would have to go hand in hand with efforts to slash emissions.
The authors are freelance journalists for China Daily.