Think back to the whole 'acid rain' theme some of us lived through growing up. The phenomenon was discovered in 1972, but it took over 20 years before legislation with teeth was actually implemented, and 30 years before significant reductions were measured. And this was on a phenomenon with relatively few point sources responsible for a large portion of emissions, something fairly easy to regulate.

There's no questioning the science behind climate change, IMHO, but the lack of definitive, practical action is due far more to an inherently myopic political process. Politicians have very limited incentive to look at any project with benefits beyond the date of their next re-election.

You can blame it on Trump and his supporters, if it makes you feel better, but I'm hard-pressed to identify a democratic government which actually implemented policies which result in any significant real, measurable impacts on climate change. Democratic leaders are rewarded for appearing to take action, far more than would be if they actually did something.