It's an interesting question to ponder what could have been done had they knew how big a problem it would be (imagine going back in time, but lacking any technical knowledge to bring).

* I wonder how much investing in solar would have been worth it. The tech was carried over by a huge investment in semiconductors that helped silicone tech on the side. If you go back early you probably end up replicating it and that costs a lot? Or I could be wrong here.

* Wind tech was probably doable. You could have iterated over designs, material science was behind but not that much I think. Nuclear was reasonable too.

* CFLs were developed in the late 70s. One could have done an early version of banning incandescent lighting. Blue LED lightening weren't invented yet and took a breakthrough.

* Probably even more stringent fuel mandates. Electrical vehicles were in the future, you could have brought them forward by a decade or two, but in the 1980s they weren't an alternative, and I don't think in the 90s either?

* Of course, the US could have mandated solar water heaters where the climate allows.

We can imagine an alternate past where green tech was wind + nuclear, and lightening was CFLs.