There was more than a whiff of irony in the air last week when Paul Dacre, the editor of the Daily Mail, mounted a spirited defence of the discredited Press Complaints Commission (PCC) during his appearance before the Leveson inquiry into phone hacking and other misdemeanours by UK newspapers.

He argued strongly that self-regulation is “in a country that regards itself as truly democratic, the only viable way of policing a genuinely free press”.

Dacre is chair of the editors’ code of practice committee, whose resulting code is overseen by the PCC. The first rule of the code is: “The press must take care not to publish inaccurate, misleading or distorted information, including pictures.”

Yet the Mail’s recent coverage of climate change and energy issues offers a clear demonstration of how an unaccountable newspaper editor can simply ignore the PCC’s rules when he chooses to promote its own ideological views over the best interest of his readers.

The Daily Mail has always struggled to cover climate change in a competent manner, particularly as its opinion columns have acted as havens for ludicrous ideological outbursts by the likes of Melanie Phillips, who last month ranted against “the faddish fixation with man-made global warming, for which no shred of reputable scientific evidence exists”.

But there has been a step-change over the past few months in the newspaper’s anti-science campaign on climate change, thanks to a plan allegedly stitched up at a lunch between Dacre and Lord Lawson of Blaby, who heads the Global Warming Policy Foundation.

The main aim of the Daily Mail campaign has been to convince readers that the rising cost of living is mainly due to policies to reduce UK emissions of carbon dioxide and other greenhouse gases. A key part of this campaign has been to promote doubt about the scientific evidence of climate change.

Hence an editorial earlier this summer stated that “the Mail urges ministers to do what they can to ease the corrosive effects of inflation by halting their politically correct obsession with green energy taxes”, before claiming that “the science of climate change remains shrouded in doubt” and concluding: “ministers must drop their dogma about global warming.”

The trouble with these strong words is that they are inaccurate and misleading, in direct breach of the editors’ code of practice whose enforcement the PCC is to enforce.. They are not even consistent with the reporting of the newspaper’s admirable science editor, Michael Hanlon, who recently pointed out that “the relationship between carbon dioxide concentrations in the atmosphere and overall temperature remains one of the simpler relationships,” and concluded: “we can do something about our – probably quite dramatic – influence on Earth’s climate.”

And indeed, the newspaper’s owner, the Daily Mail and General Trust, also appears convinced about the science of climate change, proudly trumpeting its success in reducing the company’s reductions in emissions.

But the biggest inaccuracy of all in the Mail’s coverage is its contention that climate change policies are the main cause of the recent rise in household fuel bills. As the energy regulator Ofgem indicated last week in a factsheet, “while the environmental and network costs are increasing it is wholesale energy costs, which can fluctuate widely and are dependent on global prices, that are having the greatest impact on energy bills”. It stated that “higher gas prices have been the main driver of increasing energy bills over the last eight years”, before offering the following explanation:

“This is the year that Britain first imported more gas than it produced itself. Becoming more reliant on imported gas has meant that British gas prices have become increasingly influenced by global events, especially those that affect the oil prices as often European gas prices are linked to the oil price.”

Of course, the newspaper’s coverage of Ofgem’s findings neglected to mention any of this.

Perhaps what is even more shocking is that while the Daily Mail has been publishing all this propaganda about the supposed costs of tackling climate change, it has been simultaneously been carrying out a campaign to reduce the environmental impact of plastic bags. The newspaper supports retailers charging shoppers more for plastic bags on the grounds that it is “a good green tax” and it means “less litter, less landfill, less harm to wild animals and birds”. Yet the Daily Mail remains ideologically opposed to the use of green taxes to encourage energy efficiency and reduce greenhouse gas emissions.

So if Dacre wants to strengthen the case for continued self-regulation of the UK press, perhaps he should consider how it is currently being undermined by his own newspaper’s coverage of climate change and its blatant disregard for the PCC’s rules.

• This article was amended 17 October 2011. The original referred to the committee that oversees the editors’ code of practice as a PCC committee. This has been clarified.

• Bob Ward is policy and communications director at the Grantham Research Institute on Climate Change and the Environment at London School of Economics and Political Science.