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tdons

Plant a tree.

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They have a nice graph on this page describing the problematic nature of that comment:

https://climeworks.shop/how-it-works/

EG the land area + fresh water cost to support a similar revmoval of C02 through forestation is an untenable strategy

I don't know man, the world is a big place and growing trees parallelizes nicely.

Cut them down and make buildings out of them, land area problem solved. The fresh water cost I don't buy, there's rain man, it's free.

Trees that grow and die and decompose release their carbon back into the atmosphere. The only way to make tree-growing carbon negative* is to sequester the grown trees underground.

*edited from “neutral”, sorry, typo

It takes years for a tree to grow and decades, possibly hundreds of years for a tree to decompose in its entirety through natural processes (that is, after possibly decades of life).

It is a viable solution.

Edit: if anyone disagrees look up about the Carboniferous period

The Carboniferous period stored that much carbon because the microbes at the time were unable to break down wood[1]. So yes, everyone should read about the Carboniferous period in detail to understand just how many millions of years of stored carbon in ancient plant material we're recklessly blowing out into the atmosphere all at once.

1. https://www.nationalgeographic.com/science/phenomena/2016/01...

Yes, and trees still take a lot of time to decompose

> The computer model calculates that the “residence times” (how long a tree will take to completely decompose) for conifer species range from 57 to 124 years, while hardwood species are typically around on the forest floor for 46 to 71 years

(I'll stand corrected on the hundreds of years, but it's still a long time)

https://northernwoodlands.org/knots_and_bolts/tree-falls-in-...

We use trees though. We build all kinds of things with them. Granted I would rather see native revegitation, often not great for building with depending on where you live. But given the circumstances and timescales involved, planting trees may give us some buffer time in the form of an initial dip in carbon.

Trees can be one element of many to mitigate emissions, but too often trees are bandied about as a complete solution, and it's greenwashing that distracts from the true scope of the problem at hand.

That argument gets brought up again and again, and is just wrong. Can't people see the basic contradiction in that reasoning? Trees have always died!

What matters with forest-based offsetting is the increase of forest biomass - the deaths of individual trees don't matter. If you grow a forest, the corresponding CO2 is offset for as long as the forest stays there.

We have burnt through hundreds of millions of years of fossil fuels (aka trees) in the past couple centuries. How can we regrow that “forest” one time and make a dent in carbon emissions?

Edit: I’d be happy to proven wrong, I just can’t imagine how if we increased the today’s biomass by an incredible percent, it would come close to the amount of carbon stored over millions of years.

Edit 2: 1.2 trillion trees would cancel out 10 years of human CO2 emissions. The planet currently has 3 trillion trees https://e360.yale.edu/digest/planting-1-2-trillion-trees-cou...

I was just refuting the incorrect statement: "The only way to make tree-growing carbon negative* is to sequester the grown trees underground."

It would indeed be foolish to believe we can halt climate change just by growing trees. But AFOLU is part of the toolkit we need to use (the most important tool in this toolkit is sobriety).

Trees require arable land. Trees require water and nutrients. Trees that aren't turned into treated lumber (to prevent decomposing) or buried return the carbon to the system when they die. Most interventions to plant them, water them, fertilize them, or store them at the end will use additional carbon-based energy and negate the benefit. They typically take 10 or 20 years to grow to consume the promised amount of carbon.

Trees are great, but they will not solve the climate issue alone and the notion that they can needs to be put away so that we can plan realistically.

What people miss is that we both cut down trees and burned buried carbon. To reverse global warming we need to reverse both.

Better: protect a forest.

Most solutions to climate change are subtractive, not additive.

>Plant a tree.

How does it compare to what they offer? (as in, metrics please).

About half the mass of a tree is carbon. Seeds cost a couple cents. Plant a big tree (oak, let’s say) in an area where it’s unlikely to burn down and it’s probably good for 1000kg of carbon storage.

Comes with a lot of other benefits too.

What was the land used for before? It doesn't come for free.

This is addressed on the website. I think at scale afforestation becomes a very risky prospect financially and requires a much larger amount of land putting biodiversity at risk and infringing on agriculture as apposed to the proposed CO2 remove technology. The cited paper for this on their website is unfortunately paywalled but I would be really interested in finding out more about this.

Big brain time. Biodiversity isn’t at risk if you plant different kinds of trees in different places. You don’t need to build a massive forest in any given place. Simply rebuilding the forests we used to have would go a long way.

No one is advocating for stopping conservation efforts or reforestation. But we will need a combination of solutions in order to reverse existing damage and meet targets.

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