The EU past a lot of actually good policy in the last term. Namely ban of fossil fuel cars 2035, limiting certificates for the EUs carbon market, new carbon market for transport and housing and a bunch of other laws, which actually have some positive impact. For the most part the EU parliament was not only in favour, but activly pushing for it being one of the most pro enviromental policy parliaments in the world. That is probably going to stop and they likely try to kill some of the laws passed. So the key in the future will be defence for most enviromental groups. The laws which have been passed will lower emissions, but not fast enough.
As for nuclear the EU is so far this year at 73.2% clean electricity. The large countries with a lot of fossil fuels are Poland, Italy and Germany. Of those only Poland is activly pushing for nuclear. The EU parliament is not able to force the other two to do that.