Abstract
Many modeling studies depend on direct air capture (DAC) in their 1.5°C stabilization scenarios. These studies rely on assumptions that are overly optimistic regarding the cost and scaling-up of DAC systems. This can lead to highly misleading results that can ultimately impact the ability to reach climate stabilization goals.
The issue with trees is they are part of the short-term carbon cycle. Humans are stealing power from the long-term carbon cycle. Once carbon gets released from the long-term cycle, it takes millions of years to put it back. Putting carbon from the long-term cycle into the short-term cycle kinda works, but it doesn’t really help. All of that carbon gets released back in a couple of decades to maybe a hundred years.
There are many many other issues with planting trees, but the only real solution is to stop stealing power from the long-term carbon cycle.
You’re supposed to landfill the trees after they’ve reached maturity. Pick a species that makes wood mass quickly, cut once it maxizes, cut and dump in a land fill and repeat. This of course after we’ve stopped putting old carbon into the atmosphere.
How would you ever contain the co2 gas? It will simply diffuse out. People have enough issues with containing radioactive waste, and that’s a solid encased in layers of steel and concrete made to be watertight and stored in deep storage. Containing a gas in soil for a longer while is impossible I would think.
Simply putting it into a landfill will cause it to decompose and release the carbon in the form of carbon dioxide and methane.
This is actually a big problem in permafrost regions. As the region became permafrost, the plants died and got compacted. Because of the cold, not all of it could decompose. Now as the climate heats up, these cold regions once again become warm and the decomposition resumes. There’s places where pockets of methane gas collect, you can punch a hole on the ground and light it on fire. The methane normally releases on its own without humans around to burn it off. Since methane is so much more powerful of a greenhouse gas, this contributes to climate change substantially. That’s why in places where methane gets released it’s usually demanded by law to burn it, because that way it’s only co2. Co2 is still bad, but better than methane.