And if we’re talking about economics, also known as the “dismal science,” that’s right: California’s climate change policies have failed. Climate science can tell us the Earth is warming. What it doesn’t measure is freedom: how much of yours a policy is worth, or whether imposing it on you is worth the cost. California’s air isn’t sealed off from Nevada’s by some kind of glass dome — climate change is global, but that cuts both ways. Asking Californians alone to bankroll the world’s climate conscience is a very expensive kind of unfairness — not leadership.