Restoring natural forests is the best way to remove atmospheric carbon

Because a solution that can only possibly delay the climate change by a decade or two with extreme change to global ecosystems by immense program of forestation is no solution at all. Seriously, what’s the point of doing this, if it require extreme global efforts, and will only make marginal difference? It is much more cost efficient to simply replace emissions with (also rather inefficient) solar and wind, not to mention nuclear power, instead of offsetting them by planting trees, which has no chance of having any effect other than delaying the climate change by a few decades theoretically, and a few years in practice.

The question rather is, why are you so hung up on the idea of planting trees, if it’s not going to make any difference?

> Also, if a tree dies, it frees up space for another tree. So in effect, as long as you keep those 1.2T trees growing (and replace any dead ones promptly), you will keep that carbon sequestered.

Indeed, these 1.2T live trees will sequester the carbon. I do not question that. What I question is the point of doing that if you keep emitting carbon: this will only delay the climate change by a few years, because after you use up all available space and grow these 1.2T trees to maturity, you won’t be able to capture any extra carbon: all carbon captured by the trees will be offset by the carbon emitted by decaying dead trees (or huge forest fires, which are inevitable if you don’t remove fuel from these huge foerests), unless of course you bury them.

> Feel free to do so, but you haven't provided any reason why it won't work.

No, I did, you’re just ignoring it. Again, to recapitulate: planting trees will not offset carbon dioxide emissions unless you take on extreme effort to bury these immense amounts of lumber (which would also be stupid if you keep removing more fossils from the ground and burning them). Planting trees will only delay these emissions, by the length of time that is relatively trivial compared to extreme effort necessary, and insane amounts of ecosystems destroyed. Planting 1.2T trees would destroy so many ecosystems that it would be more ecological to simply do nothing.

Planting trees to offset carbon dioxide emissions from fossils is like putting a yoghurt cup under leaking drain pipe. It will work for a while, until the cup overflows, at which point you’re back to square one. You can then replace cup and pour out water in some other drain (that is, bury the lumber), but that’s stupid, because the whole point of a drain is to pour waste water into it, and if it is leaking, you should fix the leak instead of using some silly cup-to-other-drain scheme. Similarly, planting trees will only delay the inevitable, and when the cup overflows, that is, the tree dies, you need to figure out some other way to sequester the dead tree.

> Indeed, these 1.2T live trees will sequester the carbon. I do not question that.

It seems we agree that as long as these 1.2T trees are living (and any ones that die are replaced), the carbon will be sequestered. As long as humanity can keep on doing that, the delay will be... indefinite. Are we in agreement on that point?

With the leaky pipe analogy, it seems you are worried we'll run out of room to put dead trees. Indeed, burying them is a great idea, and that can be combined with Hügelkultur technique to produce better growing conditions for other plants, including... more trees.

As far as some of the other concerns you raise: the Trees.org organization can have a tree planted for $0.10 (by people who are happy to plant it and take care of it). By that measure, it seems this method is the least expensive (if we judge effort by the amount it costs) and least extreme of all. Will Trees.org be able to scale to 1.2T trees? It's hard to say. They've planted 155M trees so far, so they need to scale by a factor of ~10000x. It will certainly be hard, but it seems to be possible: we have room for them in places where trees previously grew (see the link to the study where the 1.2T number comes from). Recently, India planted 50M trees in one day; a startup has a goal to plant 500B trees by 2050 (if they have two equally-capable competitors, the 1.2T quota can be met before then).

What ecosystems will be destroyed by planting trees? Currently deforested areas? That seems hard to believe.

I view any carbon sequestration efforts to be a partial stop-gap effort until the world becomes mostly electrified and using renewable/nuclear energy. I am for all kinds of carbon sequestration efforts, but as a consumer, I would like them to be relatively inexpensive, and not have an unknown side effect. Planting trees meet both these requirements.