I re-ran my world energy predictions with higher resolution production data from 1980 to 2004. The new projections show growth rates dropping for fossil fuels, with depletion of petroleum reserves by 2024, natural gas reserves by 2041, and coal reserves by 2099.
Using my projections of ecological footprint (from the 2006 Living Planet Report), I calculated how much energy would need to come from fuels that are not fossil-based. Last year, we would have gotten 20 percent of our energy from these other sources (hydroelectric, nuclear, solar, wind, bio-fuels, and so on). By 2020, that fraction should be 40 percent; and by 2040 it should be 80 percent.
Basing projections on each current type of fuel, the numbers look a little different. Last year’s ratio of non-fossil fuels would have been 15 percent, with the 20 percent mark reached in 2017. The 40 percent mark would be reached by 2029, and the 80 percent mark by 2048.
My projections beyond 2046 depend, of course, on the world population not crashing due to pollution and loss of other, critical species.