Saffo: Well, first distinguish between the end of the world and the end of the human species, for the events you note would be disastrous for humans, but would not cause the planet to disappear. More generally, as a culture, we become fascinated with the question of the end of the world whenever we cross a major calendar event, like the year 2000. We were preoccupied with this in 1900, and way back in 1000 A.D., Western Europeans were obsessed with the coming end times. And of course some people have been convinced on religious gorounds that the world will end at any moment for quite some time -- there has never been a time since the birth of Christianity when some portion of Christian believers were not utterly certain that the world would "end" in their life times, and today is no different.
Personally, I worry more about human stupidity than I do about natural events. And I worry most about environmental degradation in general and global climate change in particular. And I worry most about gradual degradation rather than the dramatic one-off event. Nukes are dramatic and attention-grabbing, but it would take a lot of nukes to erase the human species. Global climate change would be vastly more lethal.
Q: What about the future of media? Will there still be newspapers and evening newscasts in 2031? Will print media still exist or will everything be TV and online?
Saffo: I believe we are in the middle of a vast shift from the Mass Media world of the last 50 years to a brave new personal media world, and I've written at some length about it at: http://www.saffo.com/essays/essay_farewellinfo.pdf.
But to your specific question about paper, media are intrinsically conservative and nothing really ever goes away. For example, TVs did not make radios obsolete; radios just found a new niche in our cars. Paper will not become obsolete, but the percentage of information that is put on paper will continue to plummet. And paper may itself become smart -- with electronics imbedded in it. And we will definitely have paper-like displays that are basically flexible computer screens; these already exist as laboratory prototypes. But overall, the form factor of paper is immensely practical, and thus the form will remain even if the details change dramatically. Take a look at: http://www.saffo.com/essays/epinata.php
Q: Will we see affordable health care in our lifetime for all?
Saffo: This is a matter of public will as much as technological advances. And also the answer depends on which part of the world one refers to. Affordable health care will remain a dream for the vast bulk of the world's population who lack access to the most basic of services like vaccination and basic paramedical services today. In the developed world, apart from social and political will, the biggest issue is (as you suggest) cost, and its biggest influencing factors are discovery and technology. Discovery, especially in the genetics/genomics area, will reveal new predictive methods and treatments that may have a huge impact on health care cost and availability. For example, treating cancer with drug regimens, rather than surgery would greatly lower cost and increase effectiveness. Other technologies will have a big impact on cost and availability. Robotic surgical suites (see, for example, www.intuitivesurgical.com) will greatly expand the productivity of surgeons, and broadband communications will make effective telemedicine possible.