There are actions you can cheer on, like China's quick adoption of renewable energy. You can't make it happen yourself but you can bring peoples' attention to good things, encourage those within your circle of influence, and vote for representation that shares your views.

As for what "we" collectively can do... let's assume you are speaking of areas of research. We may need to focus on researching adaptation techniques for the areas that are going to be the hardest hit, or that have the fewest resources to cope. It's a sad topic but it may be needed. Assume the worst, hope for the best, and plan for what you can.