Last week I wrote an article in which I suggested planting trees as potentially a much cheaper way to slow or even reverse global warming, cheaper, that is, than a carbon tax. I wrote:
The third low-cost way to rein in global warming is by planting trees. Trees absorb and store CO2 emissions. You could call the tree-planting strategy geo-engineering, but it would count as such in a very low-tech form. According to a July 4, 2019 article in The Guardian, planting one trillion trees would be much cheaper than a carbon tax and much more effective. At an estimated cost of 30 cents per additional tree, the overall cost would be $300 billion. That’s large, but it’s a one-time cost. Moreover, writes The Guardian’s environment editor Damian Carrington, such a tree-planting program “could remove two-thirds of all the emissions that have been pumped into the atmosphere by human activities, a figure the scientists describe as ‘mind-blowing’.” A carbon tax, by contrast, would simply slow the rate of emissions into the atmosphere.
Yesterday I came across this CNN news story from July 30.
Ethiopia planted more than 353 million trees in 12 hours on Monday, which officials believe is a world record.
The burst of tree planting was part of a wider reforestation campaign named “Green Legacy,” spearheaded by the country’s Prime Minister Abiy Ahmed. Millions of Ethiopians across the country were invited to take part in the challenge and within the first six hours, Ahmed tweeted that around 150 million trees had been planted.
“We’re halfway to our goal,” he said and encouraged Ethiopians to “build on the momentum in the remaining hours.” After the 12-hour period ended, the Prime Minister took to Twitter again to announce that Ethiopia not only met its “collective #GreenLegacy goal,” but exceeded it.
Hmm. Let’s round 353 million trees down to 333 million. That’s one third of a billion. My article said that we need about 1 trillion. So during that one 12-hour period, volunteers in one country achieved 1/3000 of what was needed. Imagine that 50 times as many volunteers in other countries were as efficient as the Ethiopians. In a 12-hour period, they could plant 50 times 1/3000 or 1/60 of what is needed. So all we would need is 60 such 12-hour periods per person. Stretch that out over 3 years, and it means volunteering to take one long day to plant trees 20 times a year for 3 years.
Of course, that’s not the least-cost way. Far cheaper would be for millions of rich people like me and a number of our readers in rich countries to put up, say, $500 each, and hire low-income people in poor countries to do it. I won’t bother working out the math, but you can see this is not a very expensive proposition. And if you think it is expensive, compare that to the amount of high-value time spent arguing and lobbying for (and against) a carbon tax.
READER COMMENTS
Rob Rawlings
Aug 28 2019 at 11:24am
Seems like this trillion tree things is already sponsored by UN since 2011.
https://en.wikipedia.org/wiki/Trillion_Tree_Campaign
Its curious why this is not much more prominent in climate change discussions.
Rob Rawlings
Aug 28 2019 at 12:02pm
No idea how valid it is but this is interesting:
https://daily.jstor.org/could-a-trillion-trees-really-save-the-planet/
RMT
Aug 29 2019 at 3:34pm
Because planting trees does not give the government more money and power over people’s lives. Planting trees actually can help solve a problem that the global warming people don’t want solved – short of more carbon taxes, cars off the road, vegan diets, etc.
Steve Fritzinger
Aug 28 2019 at 11:39am
What’s the survival rate of those trees?
A local park did a huge tree planting project several years ago. I’d guess fewer than 1 in 100 of those survived.
David Henderson
Aug 28 2019 at 12:37pm
THE right question to ask. I don’t know the answer but clearly the answer matters.
Dylan
Aug 28 2019 at 2:54pm
I believe the type of tree and location where they are planted are pretty important too, in terms of their ability to suck carbon out of the atmosphere.
robc
Aug 28 2019 at 1:00pm
I was thinking about this the other day after your article.
Trees across America would be a fun proposal, like the Hands across America, except everyone plants a tree or three.
3 trees per American would be about 1 Billion, so 1/1000 of the total needed, and it could be done in a day (although I doubt the full 1 billion).
Econymous
Aug 28 2019 at 1:05pm
I wonder what this looks like in practice. In much of the US, the forests have multiple times the number of trees that were there pre-Columbus – they are smaller and are encroaching on meadow habitat that frequent natural fires kept them from spreading to before. More trees often means less wildlife habitat (meadows are important), greater fire risk, and increased water usage (more small trees consume more water that fewer large trees per lb CO2).
There’s also historically been deliberate planting of non-native trees like eucalyptus or Monterey pine to places outside of their native ranges, and the long-term co2 outlook can be negative – they crowd out larger native trees and can deplete soil carbon.
I’m sure there are lots of positive tree-planting projects. But seeing California’s experience, where crowded forests are costing scarce water, causing catastrophic fires, crowding out wildlife, and sometimes sequestering less carbon than their natural counterparts, makes it clear that it’s more nuanced than the sheer number of trees.
RPLong
Aug 29 2019 at 9:49am
Sure, nuance is great. But don’t let it distract us from the overarching concept. You live in California, I live in Texas. In Texas, the planting of low-water-consumption, local trees that once grew all over the place has the following benefits: (1) The trees reduce carbon; (2) The trees provide much-needed shade and temperature regulation in urban and suburban areas; (3) The trees’ roots provide crucial protection against flooding, which is quite common in Texas; (4) The trees improve biodiversity in the region by offering a place for local birds, bats, and insects to go.
The list could certainly be expanded. The point: Just because the planting of more non-native trees might be bad for California doesn’t mean the planting of native trees across the United States would be largely counter-productive. This is not the kind of nuance we need.
I also understand that Joshua trees and saguaro cacti need to be replenished. There is plenty of room to get the tree-planting thing right.
Econymous
Aug 29 2019 at 6:28pm
There is a lot of ugly deforestation in Texas, for sure. There are also native trees in Texas that are denser than pre-settlement, to great environmental detriment. Ashe junipers (referred to as “cedars” in Texas) have a similar story as some of California’s native species run amok: they sequester little carbon compared to their larger hardwood counterparts, take up more water, and pose greater fire risk.
Every Forester would agree that more trees isn’t necessarily better. More of the right trees in the right places is better. This nuance is absolutely critical to understand, or else we’ll have individuals and governments planting fast-growing trees where they don’t belong or managing forests poorly, causing long-term damage.
When I said “I wonder what this looks like in practice,” this is exactly what I mean. There’s definitely historic precedent for planting done very wrong – what are the odds that TCEQ would do it right if funded for it?
Alan Goldhammer
Aug 28 2019 at 2:23pm
The amount of deforestation in the US is not as great as many might think. HERE is a pamphlet from the US Forest Service with the data. A lot of the forest clearance here was for farm land (including pasture). It’s not likely that such land will be reforested.
Arid regions such as Ethiopia require certain species of trees that can grow in that area. Lot of freshly planted trees perish in the first 1-2 years because of climate conditions and pest infestation. It is an open question whether the Ethiopian experiment will succeed.
nobody.really
Aug 28 2019 at 3:55pm
After calculating how much it would cost to plant all these trees, given the attrition rate, then calculate how much it would cost to get people to simply stop chopping down trees that are already growing–say, in the Amazon.
“If he’d just pay me what he’s paying them to stop me robbing him, I’d stop robbing him.” Butch Cassidy and the Sundance Kid (1969)
Borys Panasenko
Aug 28 2019 at 4:21pm
Unless you suggest planting redwood exclusively, the problem with the trees is that they require trimming from time to time, and also they die in 30-50 years. And after that they rot, absorbing oxygen and letting CO2 back into the atmosphere. You can’t oversmart Mother Nature.
Anon
Sep 2 2019 at 12:02am
30-50 years???
linda seebach
Aug 28 2019 at 10:58pm
When we visited Turpan, in Xinjiang (nearly 30 years ago now) they were planting trees all around the city, in concentric circles expanding outward about half a kilometer a year. Approaching on the bus, you could see the first signs of greenery in the desert, growing taller as you got closer.
I don’t know how that project is going, but I see China is still planting trees.
(It was August, and hot; but you could walk comfortably in the middle of town, because the streets were shaded by grapevine trellises arching overhead. They’re still doing that, growing grapes and raisins.)
Shane L
Aug 29 2019 at 4:04am
I’m a bit puzzled by the idea that planting trees will reduce CO2 in the long run, following this article in The Atlantic about the role of the Amazon forests in reducing CO2:
“…the Amazon’s contribution to our planet’s unusual abundance of the stuff is more or less zero…. Contrary to almost every popular account, Earth maintains an unusual surfeit of free oxygen—an incredibly reactive gas that does not want to be in the atmosphere—largely due not to living, breathing trees, but to the existence, underground, of fossil fuels.”
Peter Brannan explains that almost all of the CO2 removed from the atmosphere by plants is returned to it by living organisms that devour plants. CO2 is captured, in the long run, by the tiny fraction of plant matter that isn’t eaten, but instead slips into places where it cannot properly decay, such as peat bogs or some ocean sediment:
“If a tree or mat of cyanobacteria or swirling hurricane of phytoplankton dies, and is quickly buried by sediment, or comes to rest at the bottom of a putrid, anoxic sea, it can escape underground before it’s unraveled. Over large swaths of time, this tiny trickle of organic carbon into the earth can swell to become a vast reservoir of buried life. And far above—at the surface world this life once inhabited—it leaves behind an equivalent gift of oxygen.”
https://www.theatlantic.com/science/archive/2019/08/amazon-fire-earth-has-plenty-oxygen/596923/
His argument is that CO2 was scrubbed from the world over tens of millions of years through the slow conversion of plant into fossil fuel matter, not by any brief growth of forests. Supposing there is a massive increase of forestry today. When those trees eventually die, do they burn or rot and release their CO2? Hence, I do not see how forestry reduces CO2 in the long run, but I’m no scientist and want to be persuaded otherwise!
nobody.really
Aug 29 2019 at 10:57am
Building on this idea: Ecologists complain that plastics hurt the environment because they don’t biodegrade. But perhaps that’s not a bug, but a feature? We’re turning petroleum into something that will nigh unto never release its carbon back into the atmosphere. What’s not to like?
Come to think of it, I’ll have TWO plastic straws, thank you very much….
Bob Murphy
Aug 30 2019 at 11:57am
Shane,
That’s an interesting article, and I have to study it and fully digest. However, let me make sure you get this distinction:
Even though any particular tree has a limited lifespan and will eventually release (most) of its CO2 back into the atmosphere, nonetheless it is still true that if we swell the # of trees alive at any moment by 1 trillion, then that translates into a one-shot reduction in atmospheric CO2.
For an analogy, the proliferation of air travel means that, at any moment, there are fewer people standing on Earth than would otherwise be the case. This is true even though any particular passenger is only on a plane for a few hours on average.
Floccina
Aug 29 2019 at 9:36am
Isn’t the biggest cost of trees the land?
Richard Black
Aug 29 2019 at 3:09pm
In 500 years where will that carbon be? If it is not removed from the system, planting trees does no good. Fossil fuels removed carbon by being stored underground.
Anon
Sep 2 2019 at 12:18am
In the tree babies
Michael Gray
Aug 29 2019 at 5:07pm
Hang on, is this plausible? 353 million “trees”? Saplings, tubestock, seedlings, or just seeds? Have you ever planted a tree properly, so it survives and grows? Try to imagine what 353 million seedlings look like, how much space they take up, waiting to be planted and then when planted. Ethiopia has a population of around 100 million. How many of its populace would be competent and available to engage in this 12 hour planting spree? Say one third, 35 million people. That’s 10 trees per person, assuming the saplings, tubestock, seedlings, or seeds are available and distributed suitably. How much of the country is conducive to and available for viable tree planting and growth?
All in 12 hours.
This has to be fake news!
Duncan E
Aug 30 2019 at 1:21am
The BBC looked into this claim and its suspicious but possible. Podcast is here:
https://www.bbc.co.uk/programmes/p07lh06y
Thaomas
Aug 30 2019 at 8:36am
I do not understand what Henderson;s claim is.
If an optimal net CO2 emissions tax were implemented, it would have dead-weight loss of X. Part of that X would be the land and other resources that would go into increasing the amount of forest that it would become profitable to increase in order to earn the subsidy from the tax. It is tautology that the part is less than the total, but impossible for a part to be alternative the total.
Could it be that a the optimal tax on net CO2 emissions would lead to increased reforestation and no other costly adjustments? This seems highly improbable to me and I’d like to see the analysis that such a claim is based on. BTW see Tyler Cowen today — https://marginalrevolution.com/marginalrevolution/2019/08/how-hard-is-it-to-limit-airline-carbon-emissions.html
Gary Young
Sep 3 2019 at 2:16pm
It continues to astonish me that sensible people do not do the basic math on the percentage of CO2 in the atmosphere and the unlikely chance that it has any impact on atmospheric temperature, even with its slightly greater mass per molecule than nitrogen and oxygen. To the point, the share of atmospheric gases is as follows: Nitrogen 0.78, Oxygen (O2) 0.21, CO2 0.004%. Methane is even less. To consider it in numbers that are readily understandable, consider a bathtub as a representation of the atmosphere, in which the water is constantly swirling around. According to Google, the standard bathtub holds approximately 40 gallons of water, which amounts to approximately 10,000 tablespoons. 7800 tablespoons of nitrogen, 2100 tablespoons of oxygen, currently 4 tablespoons of CO2. Prior to the industrial revolution, the argument is that there were approximately 3 CO2 tablespoons in the tub. These CO2 tablespoons cooled off at a slightly slower rate than the 9,997 Nitrogen and Oxygen tablespoons, which apparently was perfectly fine. After the industrial revolution, the Civil War, the Franco Prussian War, World War 1, World War 2, the Gulf Wars, and countless other wars, in which untold billions of tons of CO2 were released, the shares of the atmosphere barely budged. Previous “record high” temperatures in the USA took place during the 1930’s, that is during the Depression, when industrial activity was at a low. But now, due to the industrialization which has spread throughout the world, primarily in China, we are supposed to panic because in our atmospheric bathtub, instead of 3 tablespoons of CO2, we have 4, out of 10,000. And this is supposedly a crisis. This single extra tablespoon of slightly warmer water is supposedly driving the temperature of the other 9,996 tablespoons of water. It is really simply ridiculous. Let’s be honest, the driving force behind the attack on CO2 has nothing to do with climate, as even the most extreme and exaggerated “studies” show that taking extreme measures will have a negligible effect on atmospheric temperature, as one would expect, given that CO2 is a negligible percentage of the mass of atmospheric gases. Rather, the attack on CO2 is driven by two political forces. First, extreme environmentalists hate the fossil fuel industries, namely coal, oil and natural gas, because they believe that they despoil the environment, and so they have latched on to this theory as a weapon against those industries. Second, governments seek more ways of taxing, regulating and controlling their societies, and what better way than to target carbon dioxide, which is generated by virtually every form of human, and animal, activity. So they generously fund “climate scientists” to gin up fear in the population over carbon dioxide. The beauty of this issue for the governments and their bought and paid for “scientists”, is that this is virtually an infinite crisis, especially once you start blaming every hurricane, snowstorm, rainstorm and drought on it. As “severe climate events” and indeed climate change will go on forever, so to will the climate change gravy train. It is the perfect pseudo crisis; hence the ferocious, unscientific attempts to shout down the voices of the many serious scientists who challenge the CO2 “narrative”, by shaming and name calling.
Comments are closed.