If Germany is conquered by Russia, there's exactly nothing done to combat climate change. Warding them off gives at least a chance to work on that and some progress.
Its much worse, just look at the map. Global warming would be massively beneficial to russia - north sea would be better used by navy (whatever remains out of it) and shipping lanes, permafrost disappearing makes much more land usable. They have massive oil and gas reserves that they need to sell, half of their economy runs off this.
Molten permafrost is unlikely to be arable soil 'just so'. Tends to be rather acidic, and teems with nasty insects. Who knows what else it thawing up, too.
There's a latent conspiracy theorist deep inside me that says they've figured out the only way to stop the warming is the complete collapse of all post-conflict industrial society and start building again.
