Power plant operators say they’ve cut carbon emissions ahead of EPA’s Clean Power Plan

A new report backed by a handful of power companies contends that carbon emissions from U.S. power plants decreased 12 percent in five years.

The “Benchmarking Air Emissions” report, which examined the nation’s 100 largest electric power producers, comes in advance of the final proposal of the Environmental Protection Agency’s Clean Power Plan that aims to reduce greenhouse gas emissions from existing power plants.

The 100 producers represent 87 percent of the industry’s air emissions, according to the report, which measured emissions changes from 2008 through 2013. The report added that 42 states have reduced their emissions — carbon dioxide, nitrogen oxides, sulfur dioxide and mercury — during the same time frame.

Texas by far has the most total carbon dioxide emissions, more than twice as much as produced in Florida. However, several other states have higher emission rates than Texas, according to the report, with Kentucky, Wyoming, West Virginia, Indiana and North Dakota leading the group.

Emissions are down from 2008; the report attributed the decline to technological improvements, more renewable energy sources, and the shift from coal to natural gas power. But carbon emissions are still 14 percent higher than they were in 1990.

The EPA proposal, if enacted, could shutter power plants, especially ones that rely on coal. The power companies that sponsored the study — Houston-based Calpine, Chicago’s Exelon, New Orleans’ Entergy and New Jersey-based Public Service Enterprise Group, or PSEG — all rely much more on natural gas-fired and nuclear power plant production.

Opponents call the proposal an attack on the coal industry, and argue that it will create too great of a reliance on natural gas power generation.

The report was also supported by environmental non-profits Ceres and the Natural Resources Defense Council.

“Most parts of the country are firmly on the path toward a clean energy future, but some states and utilities have a longer way to go and overall the carbon emissions curve is still not bending fast enough,” Ceres President Mindy Lubber said in the report. “To level the playing field for all utilities, and achieve the broader CO2 emissions cuts needed to combat climate change, we need final adoption of the Clean Power Plan.”