Large-scale engineering, the kind we'd need to do large-scale cleaning of the atmosphere, or large-scale high-efficiency hydroponic farming, or building huge earthworks to protect cities from rising sea levels, or anything else we might need to do to deal with global warming, is driven by large-scale energy production. Without energy, we can't do the things we need to do to survive without a lot of pain, suffering, and death. With plentiful energy, we can do the things we know we need to do, and new technological advancements become possible.

I wouldn't rule out nuclear energy. There are risks, but it can produce a lot of energy in a small space, and the waste is much lower volume and easier to contain than chemical energy production. In my opinion, we should've built up our nuclear energy production over the past 30 years so that coal and oil could've been phased out by now, while we developed viable solar energy tech to replace the nuclear tech.