I see a few imminent dooms facing the human race:

  1. Artificial Intelligence. Computers get better than us at everything, and we become irrelevant. They'd keep humans in zoos.
  2. Genetic Engineering. The tools for building artificial organisms will become cheap enough that teenagers can build a virus in their garage that wipes out the human race.
  3. Nuclear War. Poison the entire planet.
Dooms through natural disasters are less likely. I expect a human-made doom in the next 100 years, but the last significant natural doom was 65 million years ago. There was an ice age 13 thousand years ago, but I doubt that would reduce our population by even an order of magnitude.

If we have to be doomed, I favor doom through AI, because it would leave intelligence in the universe. So buy Intel and Google and Stratasys stocks rather than Illumina or Life Technologies or Pfizer.