> The biggest challenge in climate change (for example) is that it's simply happening on too long a timescale for the average person to pay much attention to it.
I disagree. This may be a problem, but I think the bigger problem is one that was described in a post on HN a few weeks back. Namely, that most of the folks advocating for action and sacrifice on climate change are themselves unwilling to lead by example, e.g. stop using air travel, give up or very sharply reduce automobile usage, etc.
This leads a lot of people to either 1) Write the whole thing off as some BS cooked up by elites or; 2) conclude that no one, including those who claim to care most about the issue is actually going to do anything about the problem.
You can't have Congressmen and Senators calling climate change an "existential threat" while they're hopping on a commercial airliner every week to fly back home from DC. While these folks may be correct in their assessment of climate change, their own behavior completely destroys any credibility they may have had on the issue.