With that in mind, some think EPA, at least initially, may need to focus on other ways to reduce utilities' greenhouse-gas emissions, such as reducing the need for and use of fossil-fired units by helping their customers use less power.

Many utilities say that, in anticipation of federal action on CO2, they already have taken steps to reduce their carbon footprint. "We feel like we're ahead of the curve" in reducing CO2 emissions, says Christine Patmon, spokeswoman for CPS Energy, the large municipal utility in San Antonio. She says that, among other things, CPS plans to retire its two-unit, 871-MW Deely coal station in 2018 and replace it with an 800-MW, natural-gas-fired unit the muni acquired in 2012.

CPS also has contracted with OCI Solar to build 400 MW of solar photo-voltaic capacity in Texas over the next few years and sell the resulting solar power to the muni, says Patmon. The utility expects its energy-efficiency efforts to reduce customers' demand by 771 MW in 2020.

Another key component of Obama's plan calls for the retrofitting of non-residential and residential buildings. Mickey Jacob, president of the American Institute of Architects, praises the Obama administration "for recognizing the role that energy-efficient homes and buildings, both in the commercial and in the public sectors, plays in reducing greenhouse-gas emissions." Jacob adds, "Increasing energy-efficient design, construction and building performance throughout our communities is a key element of the value proposition architects offer, which leads not only to a better environment and improved quality of life, but also job gains and lower costs throughout the economy."

Of more immediate concern to some in construction is what Obama's climate-change address portends for the Keystone XL pipeline. In his speech, the president said he would approve the pipeline only if it "does not significantly exacerbate the problem of carbon pollution."

Terry O'Sullivan, general president of the Laborers' International Union of North America (LIUNA), says he is "encouraged" by the president's words. "Since the factual record has been clearly established that the development of the Canadian oil sands would not impact greenhouse-gas production, the men and women of LIUNA look forward to building this important energy infrastructure project," he says.

But Michael Brune, executive director of the Sierra Club, says just the opposite. "The president's strong commitment to using climate pollution as the standard by which Keystone XL will be decided means his decision to reject it should now be easy. Any fair and unbiased analysis of the tar-sands pipeline shows that the climate effects of this disastrous project would be significant."