The Earth's temperature has been rising. To limit catastrophic outcomes, the international scientific community has set a challenging goal of no more than two degrees Celsius (3.6 degrees Fahrenheit) average temperature rise. Economists agree we will save trillions of dollars by acting early. But how do we act successfully? And what's the backup plan if we fall short?

Setting politics aside, Two Degrees reviews the current science and explains how we can set practical steps to reduce the extent of warming and to adapt to the inevitable changes, all while improving the...