Hundreds of solutions have been put forward for how to remove the carbon dioxide that’s been building up in Earth’s atmosphere and causing the planet’s climate to change. They range from the borderline practical – pumping it underground – to the incredibly impractical – filling the ocean with iron dust to promote the growth of phytoplankton.
But one solution stands out for its simplicity: plant more trees.
Trees are one of the many natural ways in which the planet takes up carbon dioxide from the atmosphere. Through the process of photosynthesis, trees are constantly transferring carbon dioxide into their leaves, trunks, and roots, preventing it from building up in the air. So, it stands to reason that planting more trees could offset the carbon dioxide released into the atmosphere from burning fossil fuels.
Ecologists at ETH Zurich, a university in Switzerland, ran the numbers. The result: the planet needs an additional 1.2 trillion trees to offset all of humankinds’ current carbon emissions. That’s on top of the already more than three trillion trees currently growing in forests around the world.
That may seem like an impossibly large number, but it’s more feasible than it sounds. The United Nation’s Trillion Tree Campaign has already planted an estimated 15 billion trees around the globe, while China has been coordinating its own massive tree planting campaign to combat air pollution. Even more encouragingly, a recent study found that the number of trees around the world has been increasing over the past 35 years thanks to regrowth in areas of the US, Europe, and Asia that had formerly been clear-cut for farming.
Corporations, too, are helping to drive up the number of trees thanks to the increasing pressure from investors to act on climate change and the growing consumer interest in corporate responsibility. Many companies are paying for tree plantings as a way to offset their own greenhouse gas emissions, and a host of organizations have emerged to cater to this burgeoning demand for corporate forests. In addition, there are now numerous opportunities for individuals to pay extra for tree planting when buying goods or plane travel to reduce their carbon footprints.
Still, there are likely to be significant challenges to reaching the goal of over one trillion trees. First and foremost, logging remains rampant in the world’s tropical rainforests. In places like Indonesia, Brazil, and central Africa, the financial incentive to log forests and install large-scale crop plantations is enormous. Even in protected rainforest areas where logging has been banned, illegal logging continues at a breakneck pace. South America, in particular, lost nearly half a million square kilometers of forest over the past several decades.
The pace of that deforestation could quicken, too, since much of this conversion to agriculture is happening in developing nations with booming population growth and economies. The Congo – the world’s second-largest tropical rainforest – illustrates the threat. Until recently, civil war has prevented the Democratic Republic of the Congo from fully exploiting the rainforest and attracting global investment. But as the country moves towards peace and global corporations begin to invest in agricultural operations, scientists warn that deforestation rates could exceed 3,000 square kilometers per year in the absence of additional protections.
In addition, finding a place to put more than one trillion trees could prove problematic. While the ecologists behind the 1.2 trillion tree estimate note that there is room on the planet for all of these trees without displacing existing agricultural and urban developments, the details of their study – including where they propose to put those trees – have not yet been released.
That could also become harder as climate change threatens existing forests in arid regions like the western US. Extreme drought conditions have increased the frequency and severity of wildfires, and in many places pre-existing forests aren’t growing back. More subtly, climate change is forcing the slow migration of trees westward and to higher elevations throughout the US and killing off forests at the edges of the Sahara Desert in Africa.
While these alarming trends could change the calculus for tree planting, it doesn’t change the basic fact that trees are one of the most effective and feasible solutions for battling climate change. Even if the trillion-tree goal isn’t met, every tree that gets planted can help to offset carbon dioxide emissions. Better yet, planting trees – or paying organizations that replenish forests – is something that every individual looking to reduce their carbon footprint can participate in.
Image From Noya Fields Family Flickr