I don't think we need that much construction built, for one thing. I have an even simpler idea: Cut the trees down and store the wood permanently. Left in the

I don't think we need that much construction built, for one thing. I have an even simpler idea: Cut the trees down and store the wood permanently. Left in the wild, the wood will eventually break down, and the carbon return to the atmosphere. But there must be some low tech way to preserve the wood for a century at least. That's easily long enough!