Bloomberg: Judging only by U.S. political debates about climate change, a reasonable person might conclude that the world was still stuck at square one when it comes to cutting carbon. The situation is nowhere near that dire. The world is stuck at square two. Around the globe, 39 nations either price carbon emissions, or are close to doing so. There are also 23 sub-national programs in state or provincial governments. Carbon markets are worth about $30 billion and pricing programs cover 12 percent of global...