I do not see how the maximum age of the trees matters. There is no difference between 10 generations of trees that live for 150 years and one generation that lives for 1500 years. What matters is the amount of additional CO2 which can be bound in biomass per square kilometer (comapred to the biome we are replacing) and how many square kilometers which are available for this project.

I fully support any plan that ends in the forest moon of Endor. What are even the odds we'd have fossil fuels left to burn in 1,500 years? I feel like we can safely say we'd have reached peak oil by then.

I don't know the source other than Elon Musk stated it in one of his presentations, but according to him we have five times as much fossil fuel reserves as we would need to utterly destroy ourselves with climate change. If that's right, waiting until we run out is not a solution. I realize the context was mentioning some speculation that we could push the timeline out some by planting trees. That speculation aside, we can't just wait for the oil to run out and be fine.

I didn't intend argue we should wait until we run empty on Fossil Fuels. I just can't see any way in which we'll still be consuming them in 1,500 years - either we'll have moved off them, we'll have run out, or the world will have become not compatible with life (non-exclusive "or" in this case).

Great comment and even better concept.

It's worth mentioning that sequoia along with a few other species are outliers as far as longevity. Most trees do not live nearly that long.