There’s an amazing nanotechnology carbon-capture solution. It comes in a tiny, dirt cheap package. Strew hundreds of them across open ground and a few find moist, mineral-rich soil. They use internally stored energy to send threads questing down and up.
The upward threads make little solar panels that take energy from the sun. The ones going down seek out necessary water and minerals for growth. The packages on deeper soil that get sunlight press ever upward and downward, drawing more energy, water and nutrients from the air and soil.
They build stiff, load-bearing structures with complex molecules of hydrogen, oxygen and carbon. They get the carbon from the air. Some of it goes through their downward seeking filaments and connects to mushroom networks underground. The mushroom networks put it into long-lasting chemical structures.
When they get big enough, they make more of the tiny packages that they come in and spread them without us having to do a thing. The tiny nanotechnology packages that make these huge, carbon-capture solutions are free to us.
The carbon-capture solution has a great name. We call it a tree. That’s why planting a lot of trees is one of the short list of climate solutions that will work.
The earth used to have about six trillion of them, per a Swiss-led study published in the journal Science in 2019. We’ve cut down about half of that number. We continue to cut them down unnecessarily in many places in the world.
Not only do trees cheaply draw excess carbon out of the air, they provide many other benefits.
China has planted well over 40 billion trees since 1990 in an area larger than the size of France, and has pledged to plant or conserve 70 billion by 2030. Why? For a few reasons. In some of their less forward-looking periods, they revered subsistence farming peasants and forced a lot of people into the country side. In order to survive, the people stripped the land of calories for heat and food to keep their families alive. There is a lot of land in China that was once forested and can be again.
But it’s also in aid of their goal of cleaner air for their citizens. Trees filter pollutants out of the air directly and indirectly. The air in Chinese cities is improving from the levels North American and European experienced in the 1950s in fewer decades than it took western countries to clean up their air, and in part that’s due to planting billions of trees.
Trees provide shelter and habitat for animals, insects and other plants. Tree roots keep soil in place and slopes intact. An ecosystem with a lot of trees is, all else being equal, better than one without.
Trees also provide construction material that can be carbon neutral or carbon negative as we more carefully harvest trees with electric equipment and transport the trunks with electric trucks and ships. A twelve- or sixteen-story building that has a frame of laminated beams instead of concrete and steel has a much lower carbon debt.
Plant a trillion trees and about a quarter of the excess carbon dioxide in the air could be drawn down over the coming decades, at least temporarily. China’s example makes it clear that as we move calorie-stripping subsistence farmers off of the land by giving them significant economic and social opportunities in urban areas, we have enough land for a lot more trees. About 90 million square kilometers of the world, almost ten times the size of the USA, could be forested again or anew.
Can we do it? Certainly. China’s example of tens of billions of trees in the past 30 years makes it clear that if we set our minds to it, we can. And it’s much easier than it used to be. Now we can plant trees with drones. Companies like the USA’s DroneSeed and Australia’s Airseed Technologies have developed massive hexacopters and software optimized for planting seedlings and seeds wrapped in nurturing pucks in exactly the right places to grow.
Lean young human tree planters can scramble over the ground and plant one to four thousand seedlings a day while gulping water and using as much energy as an athlete running two marathons. Drones can plant dozens of times more trees in the same period while sipping at electricity as their operators it in the shade and sip water.
There are ways this can be done badly, of course. Monocultures of trees are subject to the same challenges as monocultures of crops, being more likely to fall prey to insects and other pests. The pine borer beetles that expanded northward with global heating on the west coast of North America did so successfully in part because we reforested areas denuded of multi-species natural forests with fast-growing pine trees by the tens of millions.
And much of the carbon dioxide trees draw out of the air is returned to it when they die, all else being equal. They aren’t 100% efficient. Enough is taken out while they are alive to give us a few decades to eliminate our economy’s emissions and some is permanently stored underground. Harvesting a tree for lumber and turning it into long-lasting furniture or building frames keeps that carbon out of the air for more decades.
We must stop cutting down trees to turn them into single-use paper and chopsticks. We should cut back on cutting down forests to burn for heat and electricity, leveraging wind and solar energy powering heat pumps and other electrical appliances instead.
Trees aren’t the only nature-based solution. Prairie grasses are excellent at eating carbon dioxide and pushing carbon down into the soil through their meters-long roots, if we leave them alone. Wetlands are carbon sinks and restoring them gives many benefits, just as restoring forests does. Agricultural land is good too, but we have to stop tilling it every year, breaking up those root systems and mushroom filaments that draw carbon down into permanent chemical formations underground.
Trees and other nature-based solutions are the only scalable approach to drawing the excess carbon dioxide we’ve put into our atmosphere over the past three hundred years back out. That’s why reviews of carbon drawdown strategies find that all countries that aren’t dominated by the oil and gas industry are leaning on nature-based approaches and rapid cessation of emissions. That’s why planting a trillion trees and leveraging nature is an essential component in the short list of climate actions that will work.
As a reminder, here’s the short list:
- Electrify everything
- Overbuild renewable generation
- Build continent-scale electrical grids and markets
- Build pumped hydro and other storage
- Plant a lot of trees
- Change agricultural practices
- Fix concrete, steel and industrial processes
- Price carbon aggressively
- Shut down coal and gas generation aggressively
- Stop financing and subsidies for fossil fuel
- Eliminate HFCs in refrigeration
- Ignore distractions
- Pay attention to motivations