Aseh: Yes, I think so. If the deniers’ claims are sheker, why would we want the position to be magnified, especially if you understand the issue to be of great impact? We are a people of emes. Others have pointed out other specific reasons: economic, energy, health, protecting the briah, etc. And even if economic or natural beauty concerns aren’t strictly “Torah concerns,” we still have an interest in society doing what we reasonably can. For example, the dishes piled up high in your sink aren’t strictly a “torah concern” either.
Point worth mentioning: it was strategic to bundle all environmental issues into “global warming” rather than having hundreds of separate issues to deal with like habitat loss, energy, industrial standards, etc. Kind of makes sense to me: if you deal with major climate-changing factors, you’ll probably help a lot of the other “smaller” issues. But it’s too bad how over-simplified things have gotten as a result, and how we generally disconnected we feel from “global warming,” whereas its the equally smaller issues that have profound impacts on our personal qualities of life.