Science and technology are the only potential non-catastrophic solution to all our problems (and have been for thousands of years).
People don't accept this. Our current problems (global climate change being the big one nowadays) seem to be by-products of past sci+tech solutions to problems such as, oh, dying. But unless we want to experience massive (multi-billion person) die-offs and a reversion to the pre-industrialized world, we can only go forward.
Alas, people often argue for this reversion to past technological levels. When trying to convince them that that's idiotic, it's common to bring up life expectancy: up some thirty years in the past hundred years. But the naysayers dismiss that as unimportant: who really wants to live to be 80, anyway? 79-year-olds, not the new-agers and hippies we usually find ourselves debating with.
People really believe that the increase in life expectancy is a bunch of years tacked on to the end of life--that two hundred years ago, people rarely lived past seventy. This is patently false, though. People who made it to adulthood could easily live that long. In 1900, a 65-year-old in the US had an average of about 12 more years to live whereas in 2000 that would be 16 years. We've tacked an extra four years onto the average 65-year-old's life expectancy (and only two more years for the average 80-year-old). These are tiny, tiny gains, yet people treat them as if they're the ONLY gains. The true gains in life expectancy are not the tacking four years onto the lifespan of a 65-year-old, but about THIRTY years onto the lifespan of a newborn.
We need to stop talking about life expectancy and instead start talking about infant and child mortality: a child born in an industrialized country in 1800 had a one in five chance of dying by age 5. By 1900 it was one in ten and now it's below one in a hundred. It's not about who wants to live past seventy. It's who wants to live past FIVE.
So, yeah, if the global climate crisis were a cost of allowing a 65-year-old to live to 81 instead of merely 77, people might not think it's worthwhile, but if it's the cost of a newborn living to 30 (or 75), rather than dying by age 5...we get a very different answer from most people. People who actually appreciate what science and technology have done will not voluntarily go back. The only possibly choice is to continue to count on science and technology to solve this problem just as it's solved countless seemingly insurmountable problem in the past.
(Data sources: http://www.elderweb.com/home/node/2838 http://economics.gmu.edu/bcaplan/e311/mac1.htm )