alt Hacker NewsThe root of the German Green party goes back to anti-nuclear and anti-war movements from 1960s.
https://en.wikipedia.org/wiki/Anti-nuclear_movement
"Before the 1980s, it was unclear whether the warming effect of increased greenhouse gases was stronger than the cooling effect of airborne particulates in air pollution."
https://en.wikipedia.org/wiki/Climate_change
The original 1980 plan for the Energiewende "Energie-Wende: Wachstum und Wohlstand ohne Erdöl und Uran" called for Germany to move towards "coal+gas" or "coal+solar" scenario. Only later were added any consideration for climate change, but the highest priority, the big evil, was nuclear technology.
Greenpeace has it's roots also in the opposition to underground nuclear weapon tests. https://en.wikipedia.org/wiki/Greenpeace#Origins
Indeed, anti-nuclear sentiment predates the 1990s.
The book _The Power of Nuclear_ by Marco Visscher does a good job tracing the history from the shock of the nuclear bomb in 1945 to the enthusiasm of the 1950s and the increasing scepticism of the 1970s and 1980s.