[altacc]

Trees seem to be the solution of the day but, cynically, it seems to be a smokescreen in that some people are promoting this as the solution to climate change. No amount of tree planting is going to solve long term climate change, so it should be seen as one action amongst many. The focus on tree planting shifts the focus away from the action needed to reduce carbon emissions. It's a bit like building an extension to your house whilst the house is on fire. It'll catch up eventually.

[rossdavidh]

"No amount of tree planting..." is a strong statement. Not "we won't do enough", but "No amount..." will work? I find that hard to imagine. Is there a reason you say this?

[altacc]

Two reasons: trees are part of a carbon cycle, most of the carbon returns to the atmosphere eventually, and we don't have an infinite sized planet to keep planting forests at the same rate which we're producing CO2.

New growth forests are good at capturing carbon short term, but established forests aren't as good as the rate of growth is slower and there is more tree decay & decomposition of organic matter releasing C=2. In some places, and more common due to climate change, a forest fire will sweep through a forest and undo all that carbon capture.

If we use trees for fuel it is closing most of the cycle for that carbon, less ancillary fuel use for harvesting, producton & transport, but that doesn't solve the production from other sources. If we use wood for building & materials then the carbon capture is longer, but that's a small fraction of the CO2 capture needed.

[astrodust]

Natural forest fires have a fairly minimal impact on old-growth forests and in some cases are even necessary for them to function properly (e.g. some pinecones will only open when burned). The underbrush and younger trees burn off, the older trees are largely unaffected.

What most people don't realize is the trees that exist today are all "new", as in are less than a few hundred years old. The trees that were cut down in the 18th and 19th century are unlike anything you'd see today. Far, far bigger and longer lived, on time-scales that we're really not used to dealing with.

These capture carbon and store it for hundreds of years. When they die they will decay and be recycled back into the forest floor and soil, not necessarily burned off and released as CO2.

Sure, a half-hearted tree-planting effort is not going to solve the problem, but a more ambitious reforestation plan with an emphasis on carbon-sequestering trees instead of those trees intended to be harvested every 20-40 years could make a huge difference.

[rossdavidh]

I'm not able to evaluate the truth of it myself, as it's outside my area of expertise, but at least some who do make a living studying this sort of thing believe it's feasible: https://www.livescience.com/65880-planting-trees-fights-clim...

[malka]

I guess if we empty the oceans, and cover every inch of the earth with tree, it might work.