Good news and better news…

Here is the good news. US carbon emissions are decreasing rapidly. We’re down over 10% from our emissions peak in 2007. Furthermore, the drop isn’t just a function of the Great Recession. Since 2010 our economy has been growing, but emissions have kept on falling. The reason? Natural gas. With the advent of “fracking” technology, the price of gas has plummeted far below that of coal, and as a result, essentially no new coal plants are being built. Although gas does release carbon, it only releases about half as much as coal for the same amount of electricity. This is why — despite our failure to join the Kyoto Protocol or impose legal restrictions on CO2 — the United States is now outpacing the rest of the developed world in reducing our contribution to global warming.

Now for the better news. A technology is in the pipeline that has the potential to eliminate CO2 emissions entirely. Solar power, long believed to be unworkably expensive, has actually been falling in cost at a steady exponential rate of 7 percent per year for the last three decades straight. Because of this “Moore’s Law for solar”, electricity from solar panels now costs less than twice as much as electricity from coal, and only about three times as much as electricity from gas. Furthermore, technologies now in the pipeline seem to ensure that the cost drop will continue.

Within the decade, solar could be cheaper than coal. Within two decades, cheaper than gas. When that happens, assuming we also have electric cars, it is game over for carbon emissions.

Am I being optimistic? Not especially. Global warming might still destroy the world. But technology has given us a fighting chance and this has big implications for at least four groups of people: Environmentalists, conservatives, economists, and policymakers.