Analysis The long-running saga of drowning dogs and weeping rabbits finally drew to a close this week, with the pronouncement by Ofcom that last year’s "Act on CO 2 " advertising campaign was "not political".

Critics fear that this ruling now gives the green light to government "information" campaigns that otherwise look, sound and feel like state-sponsored politicking.

The story begins last year, as TV audiences across the UK were "informed", cartoon fashion, of the perils of global warming as a result of man-made CO2 emissions. Adverts went out across a range of media, but the one that excited the most comment was a cartoon version of the campaign – which included the aforementioned dying dog and sobbing bunny - broadcast on TV in October 2009.

The ad led significant numbers of viewers – some 939 at last count - to complain to the Advertising Standards Authority and, for reasons peculiar to the UK’s Byzantine media regulatory rules, a chunk of these were then passed onward to Ofcom.

The ASA ruled, in March of this year, that the ad was OK to air, dismissing claims that the ad was misleading because it presented human induced climate change as a fact, and had exaggerated the possible effects of climate change on the UK with its depiction of "strange weather and flooding".

It is unclear whether the ASA were dazzled by the science, or whether the complainants just missed their target. Certainly, the Department of Energy and Climate Change (DECC), which led the cross-departmental group responsible for these ads put up a spirited defence, claiming that "if there was more and more CO2 in the atmosphere, irrespective of the agency, average world temperatures would rise, causing sea levels to rise, land loss, permafrost to melt and other climactic impacts".

Well, up to a point. There certainly is a wide degree of consensus amongst climate scientists and international bodies (including the Intergovernmental Panel on Climate Change and the Royal Society) that increased atmospheric CO2 leads to warming, and that a proportion of the increase is directly attributable to human action.

Unfortunately for the alarmist point of view, there is next to no agreement on the precise relationship between increase in CO2 and amount of warming. For instance, one of the most authoritative reports on global warming in recent years – the Stern Review – quotes studies that show that for an outwardly cataclysmic rise in atmospheric concentrations of CO2 above the pre-industrial baseline of 1,000 parts per million, the forecast increase in global temperatures ranges from a mild 2.8 degrees Celsius, to a species-extinguishing 17.1 degrees.

No matter: as the ASA point out, DECC justify their position on the grounds that scientists have openly said that the most alarmist scenarios "could" happen. Pay very close attention to that word, since it features significantly in what comes next.

Although the ASA patrols UK advertising in general, it is to Ofcom that complaints of political advertising are referred. Political advertising is prohibited on television and radio under the terms of section 321 of the Communications Act 2003 – although there is also a general get-out if the ad was "of a public service nature inserted by, or on behalf of, a government department".

So was this ad political? Or just public service info? In a closely argued decision taking up some 8 pages of its latest report (pdf), Ofcom decided that DECC had sailed close to the wind, but disagreed with the 537 complainants who felt it had gone too far.

Significant in reaching this conclusion was Ofcom’s assertion that controversy did not automatically make a point of view political – and the fact that the ASA had not upheld complaints about misleading or exaggeration.

They also noted that the ad had signposted viewers to sources for additional information and, because it had ended with a small girl switching a light off, had also demonstrated to viewers a practical way in which they could help combat global warming.

Significant, too, was the c-word: "could". Clearcast, the body that pre-vets television advertising on behalf of broadcasters, gave evidence stating they "had taken care to ensure that claims were not presented in unequivocal terms, asking for conditional language to be used". Which is why the voice-over states that ? "if they made less CO2, maybe they could save the land for the children". In vain might grammar pedants point out that the conditional implied here relates NOT to whether there is a peril to be saved from, but whether saving is possible at all.

So that is an end to the matter, with government departments learning, usefully, that so long as they use conditional language and include at least one practical action in every ad they put out, they should be safe from the wrath of Ofcom and ASA.

Look forward to ads advocating compulsory killing of the first-born (a practical measure) based on the scientific assertion that over-population "could" be a cause of future famine – and genocide "might" be a means to avert it. ®