The UK Advertising Standards Authority, an independent regulator of advertising across all media, has ordered coal company Peabody Energy to stop running a national print ad that claims "clean coal" is emission-free.

The ad in question stated that Peabody Energy, the world's largest private-sector coal company, "is working to build awareness and support to end energy poverty, increase access to low-cost electricity and improve emissions using today's advanced clean coal technologies. We call it Advanced Energy for Life. Because clean, modern energy is the solution for better, longer and healthier lives."

The case was brought to the Advertising Standards Authority (ASA) by the World Wildlife Fund (WWF), which challenged whether "the term 'clean coal' was misleading and implied that the advertiser's impact on the environment was less damaging than was actually the case."

The ASA ruling reads, in part:

Although we noted that the ad stated "clean coal" technologies would "improve emissions", we considered that this was not sufficient to make clear the nature of this technology, particularly in the context of the word ”clean”. Notwithstanding the fact that "clean coal" had a meaning within the energy sector, we considered that without further information, and particularly when followed by another reference to "clean, modern energy", consumers were likely to interpret the word "clean" as an absolute claim meaning that "clean coal" processes did not produce CO2 or other emissions. We therefore concluded that the ad was misleading.

The regulatory body states: "The ad must not appear again in its current form. We told Peabody Energy Inc. to ensure that future ads did not state or imply that their technologies were emission-free or similar unless they could demonstrate that this was the case."

The decision may spur further scrutiny of fossil fuel industry claims. In a press statement, WWF European Policy Office energy policy officer Darek Urbaniak said:

The victory was mixed, however. The ASA did not uphold two other WWF assertions — that Peabody's claim "energy poverty is the world's number one human and environmental crisis" was misleading; and that the ad's implication that Peabody is working to solve energy poverty "was misleading because it did not make clear the extent of the effects on the environment of the advertiser's own coal-related activities."

In its ruling, the ASA "acknowledged WWF's assertion that the solution to energy poverty depended on renewable energy sources rather than fossil fuels, and understood that several key figures and organizations had stated that a move away from reliance on fossil fuels and toward modern, clean energy was a goal for the future both in general terms and in solving the problem of energy poverty."

But, it continued:

We understood that, in this regard, Peabody Energy considered that they were working towards a solution to energy poverty which, although differing from WWF's understanding of best practice, would nonetheless provide sources of energy to those populations that did not currently have reliable access. Although we appreciated that the use of coal-based energy to do this may be contentious, we did not consider that the ad was misleading by implying that Peabody Energy was attempting to find a solution to global energy poverty or by omitting information about the potential negative effects of coal-powered energy production.

In a press release, Peabody said the WWF's case was "aimed at stopping candid discussion about coal's vital role in alleviating energy poverty, increasing access to low-cost electricity and improving emissions."

The company responded to the ASA's ruling by adding a footnote to its advertisement that reads:

The U.S. Congress itself defined the term clean coal, and Japan and China recently have affirmed the use of clean coal technologies as important to their energy strategies. Clean coal and clean coal technologies describe today’s high-efficiency supercritical technology as well as the collection of technologies that reduce key power plant emissions of sulfur dioxide, nitrogen oxides, particulates and mercury. These technologies are in broad use globally and are commercially available.

Still, the WWF declared the ASA's decision an overall win. Tony Long, director of the WWF European Policy Office, said in a statement: