That's a particularly uncharitable interpretation.
It's much more likely is that everyone's well aware of climate change (I'm sure I've read many hundreds of articles over my lifetime), but this is the first many people have heard of SV pollution (it certainly is for me).
This would explain one post rising quickly while another fades. When people are actively flagging, however, that's an entirely different, much more insidious action.
Climate Change Burnout. I don’t flag articles on CC but I’ve been tempted to. There’s a new one every two days and they all say basically the same thing. Regardless of one’s political views, the onslaught of constant alarm can be exhausting. The people who don’t think it’s a problem are not going to be convinced by the 215th news article published this year.
There is no agenda, but people absolutely use the flagging feature for selfish reasons, e.g. “Dammit, I’m so tired of reading about this topic!” When in reality, it is intended for marking content that breaks the site guidelines.
1) Hacker News ranking isn't about "what is more important/pressing right now" to a global audience. This is about what's interesting for the hacker audience at this moment.
2) It's generally frowned upon to comment about "why isn't this story getting more upvotes", etc. In other words, it's not adding value to the conversation, so please refrain from doing so and use the upvote/flagging features if you feel outraged something isn't getting the attention it deserves.
3) If you don't like something on the frontpage then don't upvote it. Simple.
4) I don't live in SV, but many people who are "Hackers" do. The article specifically targets tech companies who have offices in SV and are impacting the environment.
It's much more likely is that everyone's well aware of climate change (I'm sure I've read many hundreds of articles over my lifetime), but this is the first many people have heard of SV pollution (it certainly is for me).