It's really ironic how the Greens contributed to global warming. Good intentions aren't enough, you also need to be informed and willing to take small steps towards the perfect future.
Not bad as a small step towards a perfect future.
The Green Party is anti-nuclear and it’s debatable whether that’s positive or not. But they also are staunchly anti-coal and other carbon based energy sources. The greens have pushed constantly for renewables, both to achieve strategic energy autonomy and lowering greenhouse gas emissions.
The Germans have introduced the first legislation to subsidize renewables, in 1990, in 2000 under a red/geeen coalition renewed as EEG (Erneuerbare Energien Gesetz) that taxed fossil electricity and guaranteed a fixed above market price for producers of renewable electricity. This is widely regarded as a major boost for both solar and wind energy. We did, however, drop the ball a little when the conservatives came back to power. We still do range in the midfield when it comes to pet capita carbon emissions.
We certainly could do better and I wish we did, but blaming it on nuclear power is fairly simplistic. If you look at https://www.umweltbundesamt.de/daten/energie/energieverbrauc... for example, then you’ll notice that our love for ICE cars is a major factor - cars are one of our major sources of carbon dioxide emissions, far more than nuclear plants replaced with gas plants.
Even when the conservatives pulled the plug on nuclear power plants in 2011, Germany just stopped decreasing emissions of its electricity production for a year or two. And this was at a time of higher gas prices, so it's even up for debate how much the nuclear exit contributed to that short stagnation.