Tackling climate change would've required people to potentially change their lives, possibly drastically and in doing so likely have a lower standard of living.
And they didn't want to.
They don't want to drive less, they don't want to fly less, they don't want smaller houses, they may say they want to do something about climate change but only so long as it doesn't actually meaningfully effect them.
I bet you can think of ways to reduce carbon output without changing square footage or miles driven.
Much of that environmental movement created the sprawl we live with today.
You can be an environmentalist (I am) and realize that much of the 'environmentalist movement' is self-serving nonsense; e.g., plastic recycling. It doesn't mean you don't care... it just means the world is less altruistic than you thought.
You look at California’s sprawl in the face of climate change, and you have to condemn a significant amount of the cliched 70’s environmentalism movements as as much about aesthetics as they were genuinely concerned about the environment.