A new book called The Future We Choose lays out two scenarios for the future: what 2050 looks like if the world continues on the current trajectory of emissions—killer heat waves, food riots, filthy air, the disappearance of coral reefs—and what it might look like if we make the radical changes necessary to limit warming to 1.5 degrees Celsius, staving off the worst impacts of climate change. Then it explains what has to happen to succeed on the second path, including how anyone who is overwhelmed by the challenge can take action today, this month, and over the next decade. (You can read an excerpt from the book here.)