Humanity emerged as the last Ice Age retreated 10,000 years ago. In geologic time, that is the blink of an eyelid. How would we cope when (not if) the next ice age arrives? Will my home state of Ohio function under a mile of ice? Can we stop the next ice age? Possibly. We could redirect more of the sun’s energy to Earth using giant mirrors in space,

Then we have to look at super volcanoes, such as the Yellowstone caldera.

The supervolcano has erupted three times over the past 2 million years – 2 million, 1.3 million, and 642,000 years ago. While researchers don’t expect another eruption any time soon, it could eventually explode, destroying life for hundreds of miles around it and blanketing North America in ash.

Can we predict such eruptions? No. Can we prevent them? Not now. Can we guard against them? Probably not, unless we go Dr. Strangelove. Luckily, humanity has infested the whole globe, so some distant former British colonies will survive and restore civilization.

Have you looked at the moon? It is just crater after crater. So is the Earth. But there are natural forces on Earth that hide the crater evidence. Continental drift and erosion hide some of the big scars, but enough remains to remind us that the universe is a dangerous place. An asteroid could hit our planet at any time and wipe us out. We have the technology to protect our home planet but we lack the will to do much about it.

If NASA is to earn its keep, it should address some of these scenarios.