Climate change is perhaps the biggest problem facing mankind today. Current estimates of mortality indirectly caused by the phenomenon run as high as 300,000 deaths per year. Even if that's way off, it's still far more deaths than those caused all the Death Eaters combined.
He's a Hufflepuff, so it should only count as half.
Yet we hear climate change mentioned in Harry Potter a grand total of zero times. Not once does someone say, "After we stop this coup, we could really do something about global warming." Not once do we hear about some wizard version of the Peace Corps that could easily take care of this thing. My rough estimate is that they could stop the effects of global warming with a thousand wizards working three months out of the year. So why is Harry spending summer break living under the staircase of a family that hates him?
You just know he's in there casting Glacius anyway because they're too cheap for A/C.