I don't think that's necessarily true. It will be expensive to switch to renewables, certainly, but the ongoing externalities and subsidies for fossil fuels are already extremely expensive to society. Even if you completely ignore climate change, the costs in terms of healthcare and QALYs just due to air pollution alone are tremendous.

We have the technology we need to solve climate change already, the problem is not that people aren't willing to make the necessary sacrifices, the problem is that it's hard to get past societal inertia and overcome entrenched special interests.