I thought that all we had to do was develop non-combustion energy sources cheaper than fossil fuels, and everything else would fall into place. I think that's still mostly correct. But I underestimated how long people who are economically dependent on fossil fuel industries, and their political allies, could delay the transition. I think that those sorts of delay-and-obstruct tactics are going to ensure we far overshoot CO2 targets before (hopefully) beginning to correct them. That's even while the technologies of low-carbon energy continue to advance at a rapid clip.

Moving energy production to renewables is the easiest part. Much more difficult is the part where we need to do something about the few billion (and rising!) gas-guzzling personal automobiles. Electric cars are simply not going to be the solution in the timeframe that matters. In the EU traffic is the only major CO2 source that continues increasing. The third big problem is agriculture, specifically meat production. Two to three billion new people who have traditionally been mostly vegetarians are now hungry for meat, and the planet simply cannot afford such a thing.

This absolutely can be a problem, because infrastructure needs political approval. Worst case is a ban on renewable generation to protect fossil fuel profits, for example.

Agriculture, deforestation are major emitters not directly linked to fossil fuels.

Cement industry, heating are large consumers of fossil fuel that are seeing very little advances compared to electrification of the transportation sector.

So just because renewable electricity starts to dominate does not mean our carbon footprint goes to zero.