Commercial profitable nuclear fusion is a maybe by the end of the century. We really need to get nuclear fission capacity built out ASAP if we're serious about global warming and the overall health of the planet. Renewables just won't get us there.
Moreover, we need to overbuild the amount of clean energy produced to the point where we can waste it on energy inefficient processes for carbon recapture that we know work. Fusion is important in terms of helping this to continue to scale / make it even more economical / reduce nuclear waste and weapons concerns. Ultimately though, it's an iterative step over fission for the problems the most urgent ecological problems the world is facing.
EDIT: Did some back of the envelope math. Nuclear energy is worst case ~ $200 USD / MWh. At 2,400 kWh/tCO2 for direct air capture, that's $14 trillion USD or ~16% of the world's GDP that would instantly get us to net 0 yearly emissions. We'd need to invest more than that to start reducing carbon levels. This wouldn't recover things since damage is already done in many places (e.g. coral reef deaths) but it would arrest the worsening of issues. Additionally, this has knock on effects that improves the economy overall (weaker storms = less money recovering from disasters).
Moreover, we need to overbuild the amount of clean energy produced to the point where we can waste it on energy inefficient processes for carbon recapture that we know work. Fusion is important in terms of helping this to continue to scale / make it even more economical / reduce nuclear waste and weapons concerns. Ultimately though, it's an iterative step over fission for the problems the most urgent ecological problems the world is facing.
EDIT: Did some back of the envelope math. Nuclear energy is worst case ~ $200 USD / MWh. At 2,400 kWh/tCO2 for direct air capture, that's $14 trillion USD or ~16% of the world's GDP that would instantly get us to net 0 yearly emissions. We'd need to invest more than that to start reducing carbon levels. This wouldn't recover things since damage is already done in many places (e.g. coral reef deaths) but it would arrest the worsening of issues. Additionally, this has knock on effects that improves the economy overall (weaker storms = less money recovering from disasters).