Right next to my little city there are large dumping grounds for snow cleared from the city streets. In fact, it is just across a major road. Some people could walk out of their yard, across the street and into the snowy mountains.
The piles get to be 2-3 stories tall, and parking lot sized. In late spring the city uses machinery to spread it out, probably because it wouldnt fully melt otherwise. The snow dump is on slightly lower ground and features drainage ditches and pipes into a local creek.
To those unfamiliar with the practice of snow removal, there is a lot of grit, gravel, detritus and dust mixed in with snow. You dont normally see it, but as it melts the snow becomes dirty looking on its surfaces. This can cause an insulation effect.
Further, a large pile of snow and ice has a smaller surface area than snow spread out; it is self insulating. It is also compressed; the city can drive their dump trucks on top.
So I had a sudden thought(if thoughts from years ago could be called sudden), that if they left the snow alone, within a few years, our local weather and biome could be drastically skewed. They could build a small glacier.
Not that they particularly need to, but its an interesting type of environmental modification that nobody seems to try.
Eventually it seems it would become self perpetuating. Maybe.