Stairway to Heaven

To people in the petrochemical and motor vehicle businesses, the solution to the climate change problem lies in ascending a metaphorical staircase of fuels, which, at each step, contains an ever diminishing amount of carbon.

Yesterday, the argument goes, it was coal, today it's oil, and tomorrow it will be natural gas, with Nirvana being reached when the global economy makes the transition to hydrogen—a fuel that contains no carbon at all.

Gas is the third step on the stairway to climate-change heaven; but even if all the coal-fired power stations on Earth were replaced with gas-fired ones, global carbon emissions would be cut by only 30 percent. So despite these savings, if we were to stall on this step of the energy staircase, we would still face massive climate change. In this scenario, a transition to hydrogen is thus imperative; but how likely is it?

The ideal way to transport it is in tanker-trucks carrying liquefied hydrogen, but, because liquefaction occurs at -423°F, refrigerating the gas sufficiently to achieve this is an economic nightmare. Using hydrogen energy to liquefy a gallon of hydrogen consumes 40 percent of the value of the fuel. Using the U.S. power grid to do so takes 12-15 kilowatt hours of electricity, and this would release almost twenty-two pounds of CO2 into the atmosphere. Around a gallon of gasoline holds the equivalent energy of one kilogram of hydrogen. Burning it releases around the same amount of CO2 as using the grid to liquefy the hydrogen, so the climate change consequences of using liquefied hydrogen are as bad as driving a standard car.