Bridges require foundations, pier columns, truss cables, and roadways in order to function. Each is necessary to the function of the whole; none has priority, and it doesn't make sense to single out any one of them as the thing that allows any of the other things to matter at all. In particular, it doesn't make sense to point at a bridge under construction that doesn't have the final piece in place yet, sneer at it because it doesn't have that piece, and suggest that it's pretty much exactly the same as no bridge at all.

20 points on average might push enough people from "unable to genuinely perceive long-term threats as threats" to "able to genuinely perceive long-term threats as threats", that it would move us past the political tipping point of collectively caring enough about doing something meaningful to both figure out what to do (devote money and resources to research) and to do it.

Individual carbon footprints are not meaningful - it doesn't matter how well an individual paddles their canoe when that canoe is in a swimming pool on a cruise liner. What matters is how the liner is piloted. If all people suddenly disappeared off the earth, except for those people who happened to be standing in Walmarts at the time, do you think that society would be better or worse at recognizing and handling abstract, long-term threats like global warming than the society composed only of graduate students would be?