I'm concerned that the "concern for the environment" is mostly green washing. It's cool to be "concerned about the environment." It's far less cool to do anything about it that's consequential.
Today's adults are talking about it, but not doing enough about it. But for many of them it only became a problem after decades of not really hearing or caring about it. They have decades of experience not worrying about it and not seeing any consequences of it.
Today's kids have been hearing about it for most or all their lives. They'll grow up seeing more evidence of what's happening and how it will impact them. They won't know a world that's not talking about it.
Is that a guarantee they'll do something about it? Of course not.