If there was any doubt Duke Energy executives are feeling frustrated by the intensifying pressure they're facing from climate activists, that was dispelled by remarks company spokesman Tom Williams made earlier this month about Southern Alliance for Clean Energy Executive Director Stephen Smith.

"He's a lying son of a bitch," Williams told ClimateWire in a story about the political battle being fought in the South over a national standard mandating increased electricity production from renewable sources. Climate watchdogs including SACE are pressing for such a standard to force backward-looking Southern utilities to embrace renewable energy sources.

Williams was responding to a statement from Smith that "[m]ost of the utilities in the Southeast tend to only want to address climate change through nuclear power," which is not a renewable energy source because of the serious environmental problems associated with uranium mining, nuclear power plant emissions and radioactive waste disposal. His quote attacking Smith was pulled after a few hours, but SACE has posted a copy of the original story on its website, where Smith blogged about the incident:

Our nation can't achieve the energy solutions we need without debating issues rationally, and it is disappointing that a utility that millions in the Carolinas rely on for electricity has officially dispensed with civil discourse.

But just five days after Williams' attack on Smith was published in ClimateWire, Duke Energy CEO Jim Rogers spoke at a gathering in Charlotte, N.C. -- and as much as admitted that Smith was right. Noting that proposals to limit carbon emissions will make coal-fired power more expensive, Rogers said his company is concerned about keeping up with a growing demand for electricity, the Charlotte Observer reported:

"The only way we could do it is with nuclear," Rogers said at Monday's Charlotte Energy Summit. "The higher the price (for carbon) goes, the stronger the case for nuclear."

SACE challenges Duke Energy's claims that the only way the company can meet its customers' demand is through new nuclear plants and the new coal-fired plant it's building at its Cliffside facility west of Charlotte, N.C. Earlier this year, the group released a report showing that while renewable energy resources currently generate enough power to serve only about 5% of retail electric sales in the Southeast, the region could meet a national renewable energy standard of at least 15% by 2015, 20% by 2020, and 25% by 2025.

The pressure on Duke Energy to defend its dirty energy choices will intensify this Sunday, when the CBS News show "60 Minutes" will interview CEO Jim Rogers about his company's continuing reliance on coal-fired power plants. Also appearing in the segment will be NASA's leading climate scientist Jim Hansen, who has called for a moratorium on all new coal-fired power plants in order to prevent catastrophic climate disruption.

In a preview of the segment available on the show's website, correspondent Scott Pelley begins by noting that Duke's 20 coal-burning power plants emit 100 million tons of carbon dioxide pollution each year and says this "makes what comes out of Rogers' mouth so surprising":

[Rogers:] Our goal line is to substantially reduce our carbon footprint, to decarbonize our business, by 2050.

[Pelley:] Four decades? That's a long time.

[Rogers:] Well, it took 100 years to get to where we are. And we can't do this overnight.

The video cuts to Jim Hansen:

2050 is too late. We will have guaranteed disasters for our children, grandchildren and the unborn. ... We are going to have to phase out emissions from coal within the next 20 years if we hope to prevent climate disasters.

Cut back to Rogers, whose demeanor darkens:

I say Mr. Hansen, can't get done, won't get done. We've got to keep our economy going. We've got to make the transition, and I'm going to do everything I can with the greatest sense of urgency to make the transition. But to do what you ask me to do now is just not doable.

Once the darling of the media for his willingness to acknowledge the reality of global warming unlike some other energy company CEOs, Rogers has come under increasing scrutiny in light of Duke's decision to move ahead with building the massive Cliffside plant, which itself would release an estimated 6 million tons of carbon dioxide to the atmosphere each year.

One of the toughest interviews Rogers faced came last month with MSNBC's Rachel Maddow, who discussed Duke Energy's opposition to the Obama administration's cap-and-trade plan for controlling carbon emissions because it wouldn't give free pollution permits to big emitters like Duke. Rogers seemed rattled by some of Maddow's hard questions, like this one:

[Maddow:] Is Duke Energy profitable?

[Rogers:] Yes, we are profitable.

[Maddow:] Then why is it that you wouldn't take the hit in terms of your profit -- even become an unprofitable company for a couple of years -- in order to make good on the fact that you've been getting all this pollution for free, and we've been paying for it with our health, and we've been paying for it in terms of our environmental degradation while you've been making profit off it. Isn't this just a way to redress what's been an economic wrong that's come out really well for you guys and really bad for us?

Rogers responded weakly, saying Duke Energy was a regulated utility whose prices were determined by state regulators. But it's hard to imagine a state utility commission rejecting a company's plan to not pass on to consumers the cost of transitioning to a low-carbon future.

Given the growing pressure Rogers is under, it will be interesting to see how he handles the scrutiny of "60 Minutes."

(Still photo of Jim Rogers from "60 Minutes" preview)