By: Alison Cassady, Director of Domestic Energy Policy, Center for American Progress and Myriam Alexander-Kearns, Research Associate, Center for American Progress.


The Clean Power Plan will expedite the deployment of renewables and cut carbon emissions and other pollutants that harm human health.

On September 27, 2016, the D.C. Circuit Court of Appeals will hear oral arguments for West Virginia v. Environmental Protection Agencya lawsuit to block implementation of the Clean Power Plan, which sets the first-ever limits on carbon pollution from the electric power sector.Leading the way in the litigation are some of the country’s biggest carbon polluters and their political allies in states across the country.

The Clean Power Plan, or CPP, is a central part of the Obama administration’s plan to address the urgent threat of climate change by cutting the country’s greenhouse gas emissions 26 percent to 28 percent by 2025. This year, the Energy Information Administration, or EIA,examined what could happen to the electricity generation mix, power plant emissions, and the climate if the CPP does not enter into force. The EIA found that the CPP speeds the deployment of renewables, shifts the electricity mix toward lower-carbon sources of energy, and cuts carbon pollution, as well as other pollutants that harm human health.

This is important progress. On its own, however, the CPP will not be enough to achieve the country’s long-term goal of reducing greenhouse gas emissions at least 80 percent by 2050.

The Clean Power Plan means more electricity from renewables.

Under the CPP, states are required to replace traditional coal-fired power plants with modern, lower-carbon energy sources, such as solar and wind power.

According to the EIA, electricity generation from renewable sources is on track to grow 3.9 percent annually between 2015 and 2030, even without the new regulations. The CPP, however, increases that annual growth rate to 4.7 percent. (see Figure 1)

electricity generation from renewable sources

As a result, the United States will enjoy a cleaner generation mix sooner. With the CPP, electricity generation from renewables—led by wind and solar—will surpass coal generation for the first time ever by 2028. (see Figure 2) Without the CPP, the EIA does not see that happening until after 2040.

electricity generation from coal and renewable sources

Notably, many experts argue that the EIA’s model is rather conservative in the assumptions it makes about the deployment and cost of renewable energy technology. Consequently, the EIA’s analysis could underestimate the impact of the CPP and other policies on the growth of electricity generation from renewables.

The Clean Power Plan will quicken carbon pollution reductions.

The shift toward cleaner energy sources will ensure carbon emissions from electricity generation fall instead of rise. The EIA found that the CPP will reduce carbon dioxide emissions from the electric power sector 18 percent from 2015 levels by 2030, the final year of the plan’s implementation. This is about 35 percent below 2005 levels. The EIA attributes these projected reductions primarily to the switch from coal to less carbon-intensive natural gas and to zero-carbon renewable sources, such as solar and wind. Energy efficiency in the residential, commercial, and industrial end-use sectors also plays a role in lowering emissions projections.

In contrast, without the CPP, power plants would emit more carbon in 2030 than they did in 2015. Emissions would be 25 percent higher in 2030 than with the CPP. (see Figure 3)

In contrast, without the CPP, power plants would emit more carbon in 2030 than they did in 2015. Emissions would be 25 percent higher in 2030 than with the CPP. (see Figure 3)

CO2 emissions with and without CPP

The Clean Power Plan will cut pollution that harms public health.

Under the CPP, electric utilities will burn less coal and switch to less-polluting sources of energy, including natural gas and renewables. As noted above, this will cut carbon pollution. It also will have the secondary benefit of reducing emissions of sulfur dioxide and nitrogen oxides. These pollutants react with other compounds in the atmosphere to form small particles and ozone smog pollution; exposure to them can trigger asthma attacks and other respiratory problems. According to the EIA’s analysis for 2030, the CPP will reduce sulfur dioxide emissions from power plants by 40 percent and nitrogen oxides by 24 percent over business as usual without the CPP. (see Figure 4)

SO2 and NOx emissions with and without CPP

When the electric power sector burns less coal, it also releases less toxic pollution, includingmercury, a powerful neurotoxin that poses a particular risk to the developing brains of infants and children. Mercury emissions from power plants and other sources deposit into rivers, lakes, and other bodies of water. Most human exposure to mercury occurs through consumption of fish and shellfish that have accumulated mercury over time. The EIA estimates that by 2030, the CPP will reduce mercury emissions from the power sector by 31 percent over business as usual without the CPP. (see Figure 5)

mercury emissions with and without CPP

But the United States needs to do more.

The CPP, while important to the U.S. strategy to mitigate climate change, is not sufficient on its own to achieve the necessary economy wide emissions reductions to avert the worst impacts of climate change. The United States must—and can—do more.

In order to limit warming to below catastrophic levels, the world’s leading climate scientists agree that greenhouse gas emissions from developed nations such as the United States need to decline 80 percent to 95 percent by 2050 compared with 1990 levels. The U.S. power sector—a significant portion of the country’s emissions portfolio—will not achieve that 80 percent goal without additional policies that build on the CPP. Without new policy action, carbon dioxide emissions from the electric power sector will be 36 percent below 2005 levels by 2040 but only 15 percent lower than 1990 levels—an important start but not enough to meet the 80 percent goal. (see Figure 6)

CO2 emissions compared with 1990 levels

States should move forward with implementing the CPP, even though the Supreme Courtissued a stay pending court review. Continued delay is not compatible with the urgency needed to cut carbon emissions. At the same time, state and federal policymakers need to demonstrate leadership and enact additional measures to decarbonize the U.S. economy by transitioning quickly to cleaner energy sources.