Emissions of Carbon Dioxide in the United States

Last Wednesday, the U.S. EPA released the list of facilities that emitted the most carbon dioxide in 2010. This is in preparation for later this year when the U.S. EPA is expected to promulgate new carbon dioxide standards for power plants. Power plants accounted for more than half of the greenhouse-gas emissions by the major emitters on the list, with refineries and chemical facilities also contributing large shares. Of the 100 largest emitters—defined by the EPA as facilities emitting more than 7 million metric tons of carbon dioxide equivalent—96 of them are power plants. Two are refineries and two are iron and steel mills. (Using government respiration data for mine collapse survival, the population of the United States emitted 170 million metric tons of CO2 by breathing last year.)

According to the United States the US Energy Information Administration that collects and reports the energy statistics, U.S. energy related carbon dioxide emissions in the United States totaled 5,426 million metric tons in 2009 (the most recent year available) down from a peak of 6,022 million metric tons in 2007. For the past ten years electrical generation accounted for approximately 40% of the carbon dioxide emissions in the United States, up from 36% in 1990 when industrial sources accounted for a larger share of the economy and significantly higher share of CO2 emissions.

EPA launched the Greenhouse Gas Reporting Program in October 2009, requiring the reporting of carbon dioxide data from large stationary emission sources, as well as suppliers of fuel that would emit GHGs if used. This is the first year that data was reported. Though EPA uses the term greenhouse gasses in their press release and program title they are only talking about carbon dioxide, though the main greenhouse substances in the earth's atmosphere are water vapor and clouds. Carbon dioxide represents less than 0.04% (386 parts per million) of the atmosphere and its significant increase over the past hundred years or so is attributed to man’s impact on earth. The other greenhouse gasses are methane (1.8 parts per million), nitrous oxide (0.3 parts per million), hydrofluocarbons (0.00025 parts per million), Perfluorocarbons (0.00086 parts per million), and sulfur hexafloride (0.000006 parts per million). The Greenhouse Gas Reporting Program (GHGRP) does not represent total U.S. emissions, only the major point sources, what EPA calls stationary sources.

The largest carbon dioxide generators on the U.S. EPA list are generally speaking the largest stationary combustion sources, the largest electrical generation plants followed by large industrial furnaces (iron and steel making and refineries that flair excess gas) that were built during the era of massive size plants and do not necessarily reflect how efficient, clean or dirty a plant is. The amount of carbon dioxide released is a function of the size of facility and the type of fuel used. According to a combined report from the U.S. EPA and the Department of Energy, coal generates 2.1 pounds of CO2 per kWh while natural gas generates 1.3 pounds of CO2 per kWh. The major users of fuel are heating of residential and commercial buildings (11%), industry (20%), transportation including cars, trucks, trains, planes and ships (27.4%), and electric power generation (40%).

The largest stationary sources of CO2 are large power plants. Coal fired power plants are with the exception of nuclear power the largest electrical generation plants, and coal which generates 38% more carbon dioxide when burned than natural gas. Ninety-two and a half percent of the coal mined in the United States is used to generate 45% of the electricity produced in the United States. To protect the environment and meet the President Obama’s pledge to reduce U.S greenhouse gas emissions to 17% below the 2005 levels by 2020 the U.S. EPA wants to eliminate coal as a fuel source for electrical power plant generation through increasing regulation of coal fired electrical generation plants and new millage and emission standards mandated for the automobile industry.

The Mercury and Air Toxics Standards (MATS) regulates mercury, arsenic, acid gas, nickel, selenium, and cyanide. MATS was finalized on December 21. 2011. This regulation will slash emissions of these pollutants primarily from coal fired electrical generation plants. According to the EPA it will cost $9.6 billion annually to comply with the MATS regulations and Industry analysts believe that 10% to 20% of U.S. coal-fired generating capacity will be shut down by 2016. The combined benefit of MATS and the Cross State Air Pollution Rule was estimated by the U.S. EPA to total over decades up to $380 billion in the form of longer, healthier lives and reduced health care costs.

The Cross-State Air Pollution Rule, CSAPR, which requires reductions of sulfur-dioxide and nitrogen-oxide emissions in coal fired plants and is estimated to cost $2.4 billion in annual costs. CSAPR was made final in July but at the end of last year, the U.S. Court of Appeals District of Columbia Circuit granted a stay to the implementation of the CSAPR pending resolution of the legal challenges. CSAPR, if eventually implemented will reduce SO2 emissions by 73% from 2005 levels and NOx emissions by 54% at the approximately 1,000 coal fired electrical generation plants in the eastern half of the country.

Now the U.S. EPA is preparing for the release later this year of CO2 regulations for power plants by releasing the list of industrial CO2 emitters. Electrical generation and automobiles and trucks account for 74% of the carbon dioxide emissions in the United States. Last summer the U.S. Environmental Protection Agency (EPA) and the Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) finalized the new millage and emission standards for automobiles and light trucks for model year 2012 through 2016. The EPA GHG standards require these vehicles to meet an estimated combined average emissions level of 250 grams of carbon dioxide (CO2) per mile in model year 2016, equivalent to 35.5 miles per gallon (mpg).

Since 1990 global CO2 emissions have gone from 21 billion tons of CO2 to 29 billion tons of CO2 in 2009 according to data from the International Energy Agency (IEA). Global emissions of CO2 increased 38% despite a 14.7% decrease below their 1990 level for the Kyoto Participants and the United States increased of about 7% above 1990 levels. The bulk of the increase has come from China, Africa, Middle East, India and the rest of Asia. The United States and 35 Kyoto participants represent less than half the world CO2 emissions and that is shrinking every year. Now the United States appears on track to reduce their CO2 emissions over 1% below their 1990 levels and fulfill the promise that President Obama made at the Copenhagen meeting in 2010 when the President pledged to reduce U.S greenhouse gas emissions to 17% below the 2005 levels by 2020.