Climate change requires building more nuclear power. Which we absolutely can do.
Renewables reduce CO2 emissions today. Building a solar farm takes months, building a wind farm takes single-digit years. They'll have recouped their construction emissions well before the first nuclear reactor comes online.
It is important to remember that the challenge we are facing is not *how do we build a fully-renewable grid", but "how do we reduce CO2 emissions the fastest". Having a 95% solar-and-wind grid with 5% fossil backup 10 years from now is significantly better than having a 100% nuclear grid 20 years from now!