The Australian Press Council has expressed “considerable concern” about coverage in the Australian of the Intergovernmental Panel on Climate Change’s assessment of global temperature rises, after upholding readers’ complaints of inaccuracies in some of the newspaper’s articles.

The Press Council said errors in the News Corp-owned Australian’s coverage were compounded by its failure to respond properly when these inaccuracies were pointed out by a leading climate scientist.

In September last year, the Australian ran an article with the headline: “We got it wrong on warming, says IPCC”.

The story, written by Graham Lloyd, stated that the IPCC’s coming climate assessment “reportedly admits its computer drastically overestimated rising temperatures” and that the world has, in fact, “been warming at half the rate claimed in the previous IPCC report in 2007”.

Lloyd based his article on a story by the UK’s Mail on Sunday, whose sister publication the Daily Mail Australia website has recently been accused by the Australian of “magpie journalism”. The Mail story stated that the world had warmed by 0.12C a decade since 1951, while the IPCC report from 2007 put this at 0.2C.

The article prompted a letter to the Australian by David Karoly, a climate scientist at Melbourne University, who pointed out that the IPCC report from 2007 actually cited warming of 0.13C per decade, almost identical to the observed rate of 0.12C.

Despite this, Karoly’s letter was placed fifth among six letters in the following day’s edition. The other five letters were critical of the IPCC, with the headline: “Climate sceptics sense a modicum of vindication.”

An editorial in the same day’s Australian accused scientists of inaccurate pronouncements that had caused undue alarm about climate change. It repeated the assertion that the IPCC’s assessment would revise down the warming trend by close to 50%.

Four days after this, the Australian amended the original story’s headline to “Doubts over IPCC’s global warming rates” and then published a single paragraph “correction” on page two of the Weekend Australian.

The Press Council said “Cameron Byers and others” complained to it about the inaccuracy that Karoly had highlighted, as well as the lack of prominence given to the scientist’s letter.

In its ruling, the Press Council said the Australian’s error was “very serious” and upheld the complaints.

“The council considers the gravity of the erroneous claim, and its repetition without qualification in the editorial, required a correction which was more substantial, and much more prominent than a single paragraph in the lower half of page two,” it stated.

The Australian told the Press Council that it accepted the headline and first sentence of the original article were incorrect, but the rest of the piece was fair and balanced.

It added that it had no reason to suspect errors in the Mail’s piece, noting that the Wall Street Journal, another News Corp title, had repeated the same error.

The Press Council said it “welcomes the acknowledgements of error and expressions of regret which the publication eventually made to it”.

“But, they should have been made very much earlier,” it added, “and made directly to the publication’s readers in a frank and specific manner. It is a matter of considerable concern that this approach was not adopted.”

A study of coverage in Australia’s major newspapers last year found that one-third of articles written in a three-month period in both 2011 and 2012 rejected the mainstream scientific position on climate change.

The IPCC has stated there is 95% certainty that human activity, such as burning fossil fuels, is the main driver of climate change, with the global temperature rising by 0.9C in the past century.

An analysis of 2,258 peer-reviewed climate science studies written by 9,136 authors between November 2012 and December 2013 found that just one author rejected man-made climate change.

The Australian published the Press Council verdict on page eight of its Thursday edition. The newspaper declined to comment on the ruling.