If John Kerry were only able to accomplish one thing as US climate change czar, he'd focus on changing the minds of the one-third of countries in the world that say they're "entitled" to pollute because they didn't before.

For Kerry, it's a fallacy that heavy carbon use is the only way to develop an economy because these nations can leapfrog from fossil fuels to renewable energy.

If we are able to cut by half the amount of carbon we're now releasing into the atmosphere by the end of the decade, he says, we may be able to meet the Paris Climate Agreement goal of keeping global temperature rise below 1.5 degrees Celsius.