It's only been in the past two generations that we truly understood the impact our civilization has had on the natural world. To our credit as a species, we have turned this obscure scientific fact about carbon cycles into one of the most important political issues of the 21st century.

Survivor species tend to have huge populations, so they can afford to lose many individuals and still survive as a species. They also tend to be small. If you're small, you need less food - which is great in a situation where famine is everywhere.

Using virtual world, a scientist in Japan can conduct an experiment using a special facility in California, watching the entire thing via a live stream - and possibly controlling the experimental equipment remotely. We can use that same kind of technology to control a robot on Mars.

I try to be realistic and pragmatic. I have a lot of hope for humanity as a species, but obviously as individuals we can be extremely flawed. We may have to go through some very terrible times in the near future, even if we ultimately survive as Homo sapiens.

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.

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.

There are definitely recurring themes in humanity's relationship with our environment. The biggest is probably adaptation, because humans are incredibly good at adapting to new environments in relatively short periods of time. The ancestors of Homo sapiens started leaving Africa over one million years ago, moving from warm, tropical climates into the freezing wilderness of Europe and the desert ecosystems of the Middle East.