The recent UN report on climate change indicated that we could be facing existential risks — ever more extreme weather events and rising sea levels — within 20 years. So what is the world to do?

Jeff Goodell, a contributing editor at Rolling Stone, joins Jeff Schechtman for this week’s WhoWhatWhy podcast. Goodell, the author of The Water Will Come: Rising Seas, Sinking Cities, and the Remaking of the Civilized World, takes us deep into the grim reality we’re already facing: By century’s end, hundreds of millions of people will be retreating from the world’s shores. From island nations to the world’s major cities, inundated coastal regions will disappear. Bold engineering projects to hold back the water may buy some time, but despite international efforts and tireless research, no permanent solution is in sight. No barriers or walls will protect us in the end from the drowning of the world as we know it.

Goodell has stated, “We’ve spent 40 years denying the risks of climate change, thinking that if we can just get everyone to buy a Prius and recycle their plastic, everything will be OK. The message of recent fires and hurricanes is that it will not be OK.”

We’re living, according to Goodell, “in a new world now, and we had better get ready.” He reminds us that it’s not too late — if we rethink almost every aspect of how we live in the world.