Climate risk alone makes it dangerous to burn most known oil and other fossil-fuel reserves (conventional and unconventional), so the more carbon-intensive and costly new fuel sources that Mann describes are even more unburnable. Ways to get more oil or gas we don't need, can't afford, and can't safely burn will hardly define the future of our energy mix.

A debate on the future of energy Read more

Mann's article contains many errors, starting with the article's title. Mann's featured methane hydrates yield natural gas, not "oil." Oil and gas differ sharply and are often not fungible. Mann oddly uses "petroleum" to mean both oil and gas, but to the U.S. Energy Information Administration and most authorities, petroleum is a liquid.

Mann states "a basic truth: Economic growth and energy use have marched in lock­step for generations." He supports this claim by a single comparison for the whole world (mixing developing with industrialized economies), for all forms of energy (diluting oil and gas with cheap coal and hydropower), during 1900-2000 (for nearly three-fourths of which real oil and gas prices were the lowest and most stable in history). Actually, Mann's "lockstep" broke with the first oil price shock 40 years ago. The U.S. used 62 percent less oil and gas per dollar of real GDP in 2012 than in 1973. When the U.S. last paid serious attention to oil, in 1977-85, oil used per dollar of GDP fell at an average rate of 5.2 percent per year. Today's oil-saving technologies are better and cheaper.

Mann says Germany is burning more coal and "steadily" emitting more carbon as it shifts to renewables. In fact, Germany's 2011-12 uptick in coal-fired power generation, offsetting pricier gas, is a blip on a solid downward trend. And despite econom­ic growth, German carbon emissions fell 2.8 percent in 2011; in 2012 they rose 1.6 percent due to a cold winter but fell after weather adjustment. Germany's greenhouse-gas emissions in 2012 were 25.5 percent below those of 1990, meeting its Kyoto obligation.

Mann asserts that "Although the cost of renewable energy is falling rapidly, it is not yet equivalent to the cost of energy from fossil fuels." In fact, new utility-scale solar power underbid efficient new gas-fired plants in California's spring 2011 auction; since then, solar got cheaper and gas costlier, with German solar systems averaging half the installed cost of U.S. ones. And new Windbelt wind farms in 2011-12 sold their output for for $25-40/MWh, averaging $32/MWh -- often competitive despite nonrenewable competitors' often larger subsidies, and without counting wind's value in hedging against volatile gas prices. Gas's price volatility, which efficiency and most renewables lack, also makes fracked gas cost about twice as much as commonly supposed, even if its roughly eight kinds of major risks and uncertainties are all satisfactorily resolved.