To understand what the future of United States’ energy mix will look like in the future, it’s useful to look back at its energy history. This one graph from the U.S. Energy Information Administration tells us a lot about how we have consumed energy in this country:

There are three themes that run through U.S.’s energy history:

We go through energy transitions regularly, largely out of necessity (running out of forests or whale oil (Peak Whale) or with the discovery of a better fuel source;

We tend to diversify our fuel mix as time goes on (again, finding new, better fuel sources) by adding new fuel sources more than we retire fuel sources;

We tend to decarbonize as time goes on (from carbon-intensive wood to coal to petroleum to natural gas).

The twentieth century saw an explosion of fuels: natural gas was heavily developed, coal reemerged as an electric fuel source, nuclear fission was harnessed for electricity generation while renewables like solar, wind, and hydro grew as well.

We can make an informed guess about the future of the U.S. energy mix and assume that these three themes will continue. It’s likely that we will continue to decarbonize (which we are seeing some with fuel switching to natural gas from coal and an increase in renewables, notably wind generation).

As for the first bullet point, there is an important nuance between past transitions and present day. The impetus to fuel switch was more observable in many cases in the past; one could look out and see a dwindling supply of trees in a forest, or run out of whales.

Energy transitions driven by climate change and carbon emissions are based mostly on indirect observations or anticipated outcomes (rising sea levels, melting glaciers, insects and other biological proxies), rather than, say, stepping outside and “seeing” more carbon in the atmosphere.