Well, what if the Soviet Union placed emphasis on avoiding ecological damage, and preserving ecology? Now, how... I don't know, Marx for some reason adopts proto-green ideals perhaps.
With that said, would this Soviet Union have done better in the long run? Could avoiding ecological damage allow it to adapt better in the Cold War? Additionally, what impact would this have on Green movements elsewhere.
This is unrealistic on many levels. Let's start with the obvious.
Being eco-friendly is something that is easy for a rich, almost post-industrial nation. This is why the environmental preservation movement sprang up in the West. The infrastructure to provide 'green' alternatives exists. Because of all the factories built on fossil-fuels and strip-mining, solar panels can be produced economically, for example.
Russia was anything but rich or industrialized immediately after the revolution. She has always been poorer than the west, due to a combination of bad administration and...yeah, pretty much bad administration before the Soviet Revolution. When Lenin took over, and Stalin after him, they set about industrializing the Soviet Union for the sake of making her competetive with the West (Central Planning being necessary for skipping at least a century of development as would occur under capitalist progression).
If the Soviet Union frets about how 'environmentally friendly' her tractor factories and hydroelectric dams are in the 1920s, she'll just get overrun by fascist invaders a few years later. If she frets about making all her nuclear reactors Generation IV in safety level in the 1950s, the technology will never be developed. If she insists on filtering the emissions from coal-burning plants and oil wells, the industry that allowed her to sustain her own bloc without much trade with the west won't exist.
You can have one or the other: Rapid Industrialization, or Environmental Friendliness. With the first, you get OTL. With the second, all the Slavs die as
Generalplan Ost is enacted due to the Soviet Union getting overrun.
You think Capitalists and Stalinists polluted for shits and giggles? Of course not. It was just cheaper (read: more efficient) to not bother with environmental maintenance until it became a problem that was big enough for them to notice, and until the technology to replace dirty methods of production emerged.