I don't understand your logic. We had a huge eruption of Mount Pinatubo back in 1991. I was in high school and remember the effects that year. It had a really big impact on global weather patterns including dropping the temperature significantly, but it certainly didn't "kill a lot of flora and fauna." Yes, there was a lot of local damage around the volcano, but that was due to the ash.
We could just build more fission nuclear reactors (and we are now, finally). Fusion is still decades away, even though they've made a big advance recently due to more efficient super-conducting magnets. And renewables really need better energy storage solutions to really increase adoption.
The fact is that with deglobalization and the fall of global institutions, every country now has to guarantee its own energy independence. In the US, that's shale oil (and natural gas). In China that's coal, since almost all of their oil has to be imported from the middle east, and China has a ridiculous amount of coal. Europe would love to switch to renewables, but let's face it, they need to spend money on their military right now, and won't be able to afford subsidizing solar panels in countries where the sun hardly shines.
The problem isn't going away.
Do you have an actual workable idea, or are we all just supposed to lay down and die? You can do that if you want. The rest of us are going to work the problem.
Do you suffer painful elimination? -- Don Knuth, "Structured Programming with Gotos"