Met quite a few of them in my job. The ones who whinge the most about why someone isn't doing something to reduce pollution/protect species/clean up rivers/etc are the ones who are least likely to be willing to support such work from their own pocket.

You can spot them pretty early on. The ones who really want to help also have a lot to say, but they say it differently. They talk to you, not at you.

Anyone with a monologue is bad news.