Every year, the Energy Information Administration (EIA) issues its best guess on what the fuel mix for the global economy will look like over the coming decades. The reference case of the EIA's International Energy Outlook 2013 assumes no changes from current energy policies.

This year's report projects that the world will be using 56 percent more energy by 2040 and that 80 percent of it will still come from burning fossil fuels. The EIA foresees that consumption of petroleum and other liquid fuels will rise 32 percent, from 87 million to 115 million barrels per day; that natural gas will increase by 64 percent, rising from 113 trillion cubic feet to 185 trillion cubic feet; that coal will grow 44 percent, from 8 billion short tons to 11.5 billion; and that nuclear's share of total energy will increase from 5 percent to 7 percent.

Total energy use from renewables is supposed to rise from 11 percent in 2010 to 15 percent in 2040. EIA expects 52 percent of that increase to come from hydropower and 28 percent from wind. Energy-related carbon dioxide emissions are expected to rise 46 percent, from about 31 billion metric to 45 billion metric tons in 2040.

In other words, there's no peak in sight for fossil fuels.