Which led me to think about death, dying, and what you can do about it.
One thing I realized about myself is when in a less pessimistic mood, I think the intensity of my motivation for trying to clean up our environment stems from an analysis I don't think many people have made. (Well except for the transhumanists)
Basically, given current predictions of life span, I should be able to live somewhere between 2050 and 2091 (79 to 120 years old). The current IPCC climate change scenarios are only predict up to 2100. There are plenty of people (in industrialized countries) who will live to see 2100. (assuming civilization doesn't collapse)
50 years ago humanity discovered DNA now we can move genes at will between different organisms, use retroviruses to add new genes to adult cells, have a reasonable map of the coding regions of our own genome, and are making progress at determining the biochemical pathways controlling cells.
So in another 50 years, since we already have ideas what controls cells aging and can immortalize cells for research, I suspect we could develop drugs to break past the currently accepted upper limit for human life span of 120 years.
I suspect by 2100, we should understand how neurons work and how they store information. With that it may be possible to copy that information into some software and then start running a simulation of the digitized brain. If you're a reductionist, the simulation should be nearly indistinguishable from the organic person.
And once you can make backup copies of yourself, pretty much the only way to cease existing is suicide or for all the copies to be in the same star system when the star dies. (or for the universe to end)
I think the biggest question is whether or not it would actually be possible to capture all of the state of a brain.