I don’t think the problem is staying alive, but staying alive with chronic illness. If medical advancement cures an illness and we are healthy, I think everything will be fine. If medical advancement keeps us dependent on medications and machines, then I think we have a problem. I never worry about food and water. I think there will always be enough food, water, energy, shelter, if we do the right thing as a world community and begin to live in peace. I know we are far from that now, but I hold out hope the earth will eventually be the utopia that I think is possible. I think probably the road to getting there will mean a lot of suffering and death.
Mother nature does take care of some of these things, but the more we advance the less affect she has on human life, but she can still have a devastating affect.
My mom and dad just got back from China, and it seems the Chinese used to have socialized medicine, but they decided to go the way of America, and now if you cannot afford health care or health insurance tough luck. People are dying. So, maybe @thorninmud makes a valid point. Just the poor. But, who is going to clean the mansions if the poor drop dead? ~ Seriously, I think eventually there will be some sort of revolution, epiphany, aha moment, and we will be able to live safely, healthy, and together.