People prefer carrots to sticks.

I sometimes think those in the environmental movement have made a mistake with their messaging. It is too often "we need to suffer to save the planet". It could also be things like:

  "Why do you want to pay more to drive a giant expensive gas guzzling vehicle to work so that you can pay for a giant expensive gas guzzling vehicle to go to work in".

  "Why do you want to pay for extra electricity when conservation and efficiency will help save money for other things"

  "Single use items are thing you pay for time and  time again. Durable maintainable items you pay for once."

  "Throwing things in the garbage is like paying to store things forever (landfills are not free)"

It's that the marginal benefit of individual action accrues mostly to other people, or (on a national scale) to other nations. The fraction of benefit that accrues locally isn't enough to justify the cost (unlike, say, the ban on CFCs, or control of local pollution.)

So absent something enforcing prohibition of defection from a collective action, the collective action doesn't happen.

You want to actually solve the problem? Find such an enforcement mechanism (CO2 tariffs, perhaps), reduce the cost of solution (sufficiently cheap non-fossil energy), or find another solution that doesn't require global cooperation (albedo modification, say).

A solution that just requires everyone to get along and cooperate to their marginal net detriment doesn't seem like it will work.