On Monday, the U.S. Environmental Protection Agency (EPA) officially released their highly anticipated rule for carbon emissions reductions in existing power plants. The numerous statements released by the EPA and White House revealed three themes - climate change, public health, and energy security.

According to the EPA's announcement:

"At the direction of President Obama and after an unprecedented outreach effort, the U.S. Environmental Protection Agency is today releasing the Clean Power Plan proposal, which for the first time cuts carbon pollution from existing power plants, the single largest source of carbon pollution in the United States. Today’s proposal will protect public health, move the United States toward a cleaner environment and fight climate change while supplying Americans with reliable and affordable power."

All told, the proposed EPA rule targets a 30% reduction of carbon emissions by 2030 in the nation’s electric power sector, compared to 2005 levels. This action follows the 2007 Supreme Court decision that upheld the EPA’s ability to regulate carbon dioxide and other pollutants that contribute to global climate change. How to achieve these reductions is largely left up to each state.

Climate Change - Looking to the future

The new rule clearly targets carbon dioxide emissions directly due to the threat that they pose to human health wellbeing as the result of global climate change. On the EPA’s website, Administrator Gina McCarthy is quoted in saying that:

"Climate change, fueled by carbon pollution, supercharges risks to our health, our economy, and our way of life. EPA is delivering on a vital piece of President Obama's Climate Action Plan by proposing a Clean Power Plan that will cut harmful carbon pollution from our largest source--power plants...”

The EPA has published significant amounts of information on climate change science and sources (see here as a starting point).

Human Health - looking at the near-term

An anticipated co-benefit of the proposed carbon reductions is an anticipated 25% decrease in other types of air pollution, including particulate matter (PM), nitrogen oxides NOx), and sulfur dioxide (SO2), which have documented human health risks (see Table 1).

Noted here is that these three pollutants are already regulated via other EPA rules under the Clean Air Act. Monday’s announcement does not change those regulations. Rather, by reducing carbon emissions, the EPA expects that emissions of these other pollutants will be reduced as well because they are largely produced by the same power plants that emit almost 40% of the nation’s carbon dioxide emissions.

An estimated 800,000 early deaths occur each year around the globe as the result of combustion-related emissions (including both particulate matter and ozone) – 200,000 in the United States alone. While these particles can come from non-human sources (e.g. volcanoes), anthropogenic sources are the major contributors in cities. Particulate matter that is smaller than 10 micros in diameter (PM10) primarily comes from combustion – in car engines (both diesel and gasoline), power plants (coal, heavy oil and biomass), and other industrial activities (for example mining, the manufacturing of cement, and smelting).

According to the President, “[in] just the first year that these standards go into effect, up to 100,000 asthma attacks and 2,100 heart attacks will be avoided – and those numbers will go up from there.” On Tuesday, the EPA released its estimates that the Clean Power Plan with help the United States “avoid up to 6,600 premature deaths, up to 150,000 asthma attacks in children, and up to 490,000 missed work or school days [per year].”

Energy Security

The third theme found in the EPA’s announcement this week was energy security – that is “a cleaner environment and fight climate change while supplying Americans with reliable and affordable power.” On one hand, power plants account for almost 40% of the nation’s carbon domestic carbon dioxide emissions. On the other hand, they also represent more than 2/3 of the nation’s electricity supply – a supply with a track record of providing a reliable supply of electricity the vast majority of the time.

Moving forward, the Obama Administration seems keenly aware that any clean energy transition will assuredly be hindered if the result is not also a reliable supply of electricity to the American economy.

The states now have until 2016 to prepare proposals for their mix of power generation, energy efficiency, and demand-side management efforts to facilitate this 30% reduction in carbon dioxide emissions.


[1] R. D. Brookes, S. Eaton, A. Griffin, A. Loader, R. Morris, J. Stedman, J. Thomas, K. Vincent, P. Willis, D. E. Connolly, and D. Waterman, “Air Pollution in the UK 2012,” no. September, 2013.

[2] S. Holgate, “Committee on the Medical Effects of Air Pollutants (COMEAP) - Review of the UK Air Quality Index,” 2011.

[3] World Health Organisation, “Air quality and health,” vol. Fact sheet, pp. 1–5, 2011.

Photo credit: Photograph of Castle Gate Power Plant near Helper, Utah by Staplegunther via Wikimedia Commons.