Too Much Pollution: State and National Trends in Global Warming Emissions from 1990 to 2007

Released by: Environment Montana Research & Policy Center

Executive Summary

America’s reliance on fossil fuels—oil, coal, and natural gas—for energy creates a host of problems, including air and water pollution, global warming pollution, high and unpredictable bills for consumers and businesses, and the need to import oil from unstable parts of the world. Moving to clean energy—such as solar and wind power, more efficient homes, and plug-in cars—will cut pollution, help rebuild our economy, and reduce America’s dependence on oil.

For decades, America’s use of fossil fuels—and the global warming pollution that results—has been on the rise nationally and in states across the country. But this trend is starting to change in some states—in part because of the move to clean energy. Following the lead of those states will start to put the United States on a path to lower global warming emissions and help drive the creation of a clean energy economy.

This report analyzes the most recent data available from the federal Department of Energy to calculate emissions of carbon dioxide from the use of oil, coal and natural gas at the national and state level from 1990 to 2007. Our analysis finds that:

  • Emissions of carbon dioxide, the leading global warming pollutant, from fossil fuel consumption increased by 19 percent in the United States from 1990 to 2007. Nationally, the rate of emissions growth has slowed in recent years, and emissions peaked in many states in 2004 and 2005.
  • Seventeen states saw declines in carbon dioxide emissions from fossil fuel use between 2004 and 2007.

Those emission reductions—while far short of what will be needed to address the threat of global warming—could be a sign of a new trend, particularly if the United States adopts strong policies to move the nation toward a clean energy future.

States that are highly reliant on coal-fired power plants, have energy-intensive industries, and/or have high levels of pollution from cars and trucks tend to produce the most carbon dioxide pollution from fossil fuel use.

  • Texas remained the nation’s number one emitter of carbon dioxide from fossil fuel use in 2007, followed by California, Pennsylvania, Ohio and Florida. (See Table ES-1.)
  • Wyoming produced the most carbon dioxide pollution per capita, followed by North Dakota, West Virginia, Alaska and Louisiana. Rhode Island produced the least carbon dioxide per capita in 2007, followed by New York, Vermont, Idaho and California.
  • Electricity generation and transportation are by far the largest sources of carbon dioxide emissions in the United States, responsible for 40 percent and 33 percent of fossil fuel-related emissions, respectively, in 2007. Power plants and transportation were also the fastest-growing sources of emissions between 1990 and 2007.

Nationally, the rate of growth in carbon dioxide pollution has slowed but emissions still remain above the levels of two decades ago and well above the levels needed to prevent the worst impacts of global warming.

  • Between 2000 and 2007, emissions of carbon dioxide from fossil fuel consumption increased at one-fifth the rate they did during the 1990s.
  • Carbon dioxide emissions are estimated to have declined by 2.8 percent in 2008 (to their lowest level since 2001) and are projected to fall still farther in 2009, due to high oil prices in 2008, the recession, and the declining carbon intensity of the economy. 
  • However, these emission reductions are far from the roughly 35 percent cut in global warming emissions the United States must make by 2020 in order to do our share to avert the worst impacts of global warming.

Carbon dioxide emissions from fossil fuel use are declining in a growing number of states as they invest in the clean, renewable technologies that are part of a new energy future. Emissions remain on the rise in other states that have not eased their reliance on dirty fuels.

  • Four Northeastern states—Connecticut, Delaware, Massachusetts and New York—emitted less carbon dioxide from fossil fuel consumption in 2007 than they did in 1990. Since 1997, gross state product in these four states increased by 65 percent while carbon dioxide emissions decreased by 5 percent.
  • Seventeen states and the District of Columbia have seen total emissions decline since 2004, a year of peak emissions for many states. Maine saw the largest percentage decline over this period, while New York and Texas—the nation’s eighth-highest and highest emitters of carbon dioxide, respectively—saw the greatest absolute declines.
  • Still, emissions in 33 states increased between 2004 and 2007. Emissions in Oklahoma saw the greatest percentage increase, followed by Montana and Hawaii. Oklahoma and Georgia experienced the greatest increase in absolute terms.

The experiences of states that have reduced carbon dioxide emissions, or have low per capita emissions, have lessons for how the nation can reshape its energy system and reduce emissions in the future.

  • Many northeastern states have reduced carbon dioxide emissions from electric power plants by switching from polluting (and expensive) oil to cleaner natural gas. Texas, meanwhile, has led the nation in wind energy installations, helping to stabilize emissions from its power sector. These states show that switching from highly polluting fuels such as coal and oil to cleaner sources of power, including renewable energy, can lead to rapid and substantial reductions in emissions.
  • Washington and Oregon are the only two states in which the number of vehicle-miles traveled on highways per capita declined between 1990 and 2007—leading to significant reductions in per capita emissions from gasoline use in both states. Both states are noted for their leadership in promoting “smart growth” and both have experienced strong increases in transit ridership, suggesting that states that provide transportation alternatives to reduce reliance on fossil fuels can reduce carbon dioxide emissions.
  • States that have made investments in improving the energy efficiency of their economies tend to produce fewer carbon dioxide emissions, suggesting that energy efficiency can be a critical tool in efforts to address global warming at the same time it creates jobs locally.

Creating a new energy future and achieving the carbon dioxide emission reductions necessary to avoid the worst impacts of global warming will require strong action at the federal and state levels, including:

Science-based limits on global warming pollution from the American economy, with the goal of reducing U.S. emissions by 35 percent below 2005 levels by 2020 and at least 80 percent below 2005 levels by 2050.

Renewable electricity standards that would ensure that the United States receives at least 25 percent of its electricity from clean, renewable sources of energy by 2025—reducing the need for continued dependence on high-polluting fossil fuels.

Policies to improve the energy efficiency of our homes, businesses and factories, including strong building codes and appliance efficiency standards, as well as funding for efforts to retrofit existing buildings to achieve greater energy efficiency.

Greater investment in transportation alternatives, including high-speed rail and modern public transportation, as well as efforts to reduce the carbon intensity of transportation fuels and improve the fuel economy of vehicles.

These and other measures to cut carbon dioxide emissions are essential to limiting the effects of global warming and will help shift the U.S. economy away from its reliance on dirty and expensive fossil fuels and toward a clean energy economy.