The events that could kill us all (and how we might prevent them)

Science journalist Bryan Walsh visited scientists from a variety of disciplines, devoured the scientific literature, and identified the catastrophic events most likely to kill us all. The list is a greatest hits of doom, from climate change and asteroid impact to bioengineered pathogens and supervolcanoes, which he wrote about this week in the New York Times. Failing those, we always have nuclear war to worry about. But fret not (too much, anyway), Walsh's new book End Times: A Brief Guide to the End of the World not only presents the disasters that could end the human story in midsentence," but also describes how scientists are trying to alleviate the risks. From a review in Science News:

To understand asteroids, he spends a night at Mount Lemmon Observatory in Tucson, Ariz., where astronomers are tracking space rocks that might intersect with Earths orbit. In theory, there are ways to deflect an incoming asteroid before it slams into Earth, such as trying to change the asteroids speed or approach. Walsh suggests that countries with space programs spend more on planetary defense and start practicing asteroid deflection. NASA and the European Space Agency have plans to do just that: In 2022, they intend to crash a spacecraft into an asteroid to try to alter its trajectory...

He also discusses more theoretical solutions that scientists have thought up, like how to cool magma beneath a supervolcano to prevent an eruption. Drilling nearly 10 kilometers into the belly of a supervolcano to inject cold water may not really be practical and could cost about $3.5 billion.