This issue is something that I've thought extensively about, consider myself pretty knowledgeable, and am not shy in talking at/with other people about. I'm not a climate scientist, biologist, etc., but I think I'm about as educated as a layperson can be on climate change (though I remain always interested in new data points/ideas).
That said, I've come to the conclusion that we have two near-insurmountable problems when it comes to the problem of climate change.
One is that humanity as a whole has spent the last 150-200 years building modern civilization off of the back of fossil fuels. Absolutely everything in the modern age--from tech to transportation to agriculture to (insert thing here)--is supported by or heavily influenced by fossil fuels. Which means every possible solution to getting off of fossil fuels is, by default, a huge infrastructure issue. Absent someone coming up with a miracle 'clean energy' solution, to solve it would require all of humanity to do a pivot-turn on a worldwide scale on how we live our lives--at least, if we want to preserve our existing civilization without catastrophic consequences to both ourselves (widespread famine, shortages in medicine, etc.) and the biome.
Quite frankly, in all of history I cannot think of a single example where humans have managed to do this.
The other insurmountable problem I've found is summed up by this quote:
"It is difficult to get a man to understand something when his salary depends upon his not understanding it." - Upton Sinclair
Per the first point above--when people's livelihoods depend on fossil fuels, they have a profound incentive NOT to believe in climate change, or if they do believe it, to downplay their own contributions and lump it all on the shoulders of 'those other people'.
It sounds really defeatist, but I think those of us who are fighting for a response to climate change have to accept that reality. And then much like a 'debt snowball', try and get a 'climate snowball' rolling--encourage tiny, win-win-win changes in ourselves and our neighbors and our politicians, and once they've achieved those, push for the next, slightly harder step. And so on. First get people talking about how there would be more money in their pocket if they reduced their electrical bill by doing XYZ (and helping combat climate change!). Then get them talking about how, for only X dollars more on their now-reduced bill, they could ensure all their electricity was renewable (and help combat climate change!). Encourage bikeable/walkable infrastructure by talking about how awful it is to have cars roaring by day and night, endangering kids and the elderly (and help combat climate change!). Then talk about banning cars entirely from some chunks of neighborhoods/investing in more transit (and help combat climate change!). And so on and so on.
The Nature Conservancy (
https://www.nature.org/en-us/) has a pretty good action plan for things humanity can do, on both an individual level and a structural one, to combat climate change. I encourage those who are truly interested in what can be done to check it out.