Everything I had read in the fields of fiction and science led me to a single, dark conclusion. Humans are screwed, and so is our planet.

The fact is that humans have been shaping the genetics of what they eat for thousands of years. Genetic engineering simply speeds up the process that used to take generations. Preventing people from getting things like golden rice or disease-resistant cassava destroys human life, and does not spare the environment in any way.

The fact that we have been able to perturb the carbon cycle with our industrial revolution is evidence of how vulnerable we are - because when we destroy our environments, we destroy our food and energy supplies. In short, we destroy ourselves.

With enough money and international coordination, we can push incoming asteroids out of Earth's path. We might even be able to bring back extinct animals in the lab. The problem really isn't scientific - it's cultural. We aren't yet able to coordinate ourselves as a global civilization to do something simple like bring food to a famine-stricken region. We can actually use current satellite technologies to predict where famine will strike next, but we can't get food there - usually for political reasons.

Humans are a great survivor species but our survival will be pretty grim if all of the plants and animals we depend on die out. That's why any human survival strategy has to include a plan to maintain our environment roughly in the state that it's in now.

I think that humans are also set up to survive. We're not as small as rats, but we make up for that by being intelligent enough to make our own hiding places and to adapt to new habitats, even if they are changing very quickly. We have an enormous population, and can afford to lose billions of people without suffering very much as a species. Indeed, some would say losing five billion people would be good for the planet - I disagree with them, but can't deny that we would do just fine if there were two billion of us or even one billion.

Even though I now know that it's likely the Earth will suffer through mega-volcanoes or meteor strikes that could take out millions or billions of people, I feel less anxious about it because I actually understand what the threats are. There's nothing like researching something exhaustively to make it less terrifying.