A Really Inconvenient Truth: CO2 Emissions Decline Driven by Fracking

US carbon emissions have declined 20% since 2005--mostly because natural gas has replaced coal in electric power generation. Data from US EIA.

It might have seemed unattainable in 2005, but we’ve done it! We have successfully lowered US carbon emissions below 1990 levels. In fact, CO₂ emissions from fossil fuels in the United States have dropped 20 percent since 2005 and are the lowest they’ve been since 1987. And that’s with a population increase of 14 percent—a 30 percent per capita decrease! And guess who made this historically unprecedented accomplishment possible? Believe it or not, it was actually Big Oil that reduced our carbon emissions.

I know what you’re thinking—no! That can’t be! Big Oil is the enemy! It’s all the wind turbines and solar panels and LED lightbulbs and electric cars that have really lowered emissions, right?

Not according to the data collected by the US Energy Information Administration, which divides carbon emissions up between the major end-use sectors: electric power, transportation, industrial, residential, and commercial. The bad news is that we’ve made practically no progress in reducing carbon emissions in most of those sectors. The good news is that the decrease in emissions from the electric power sector—41 percent—is so dramatic that it’s lowered total emissions by 20 percent. Electric power carbon emissions are the lowest they’ve been since 1976, which was when electric power became the most carbon-intensive sector.

The big factor driving this emissions reduction is the retirement of a large percentage of the nation’s coal-burning power plants. Coal is the dirtiest-burning fossil fuel and causes significant environmental damage at almost every stage of the production process—from massive open-pit and mountaintop-removal mining to large quantities of mildly toxic ash that must be landfilled somewhere. Yet the amount of electricity generated from coal increased dramatically in the 1970s because of the oil crisis.

Then came the fracking boom of the 2010s. With the combination of horizontal drilling and hydraulic fracturing, oil and gas companies could suddenly economically extract huge deposits of natural gas that had previously been inaccessible. This made it possible to construct large numbers of new gas-fired power plants. Natural gas is much cleaner than coal—it only creates one-quarter the carbon emissions to produce the same amount of electricity, the wells have a comparatively small environmental footprint, and there’s no ash.

This increase in natural gas-fired power plants also made it possible to increase the amount of electricity generated by intermittent renewables like wind and solar. When the wind doesn’t blow and the sun doesn’t shine, people still want and demand a steady, reliable supply of electricity—and, except for hydropower, natural gas plants are the only ones that can cycle up and down fast enough to compensate for fluctuating renewables. Wind and solar are now 14 percent of the US electricity mix—and natural gas is 43 percent. As long as we want steady, dependable, on-demand power, we’ll have to use natural gas to balance out the intermittent renewables. Nuclear power can’t do that because it’s not flexible enough.

As impressive as this decline in carbon emissions has been, it won’t continue much longer. Coal’s down to only 16 percent of our electricity mix now, and once that’s replaced with natural gas, there won’t be any more decreases in carbon emissions—unless we drastically reduce our consumption of all forms of energy, something we haven’t made much progress on since 2005.