The Mail on Sunday, the statement said, also failed to correct “significantly misleading statements” in the article, which was written by David Rose and based on the claims of the former NOAA scientist, John J. Bates. The press standards group, known as IPSO, was expected to publish the full text of its ruling on its website.

The man who brought the complaint against The Mail on Sunday, Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics, said that he had immediate concerns about the article when he read it.

“It was fairly obvious right from the start it was bound to be suspicious because David Rose has a long history of promoting climate change denial,” Mr. Ward said.

“It was grossly overblown,” Mr. Ward added, “and that was clearly what he was trying to do.”

Efforts to reach Mr. Rose were not successful. John Wellington, managing editor of The Mail on Sunday, confirmed in an email that the news organization was going to post what he referred to as an adjudication.

Mr. Rose’s article was published with the print headline, “EXPOSED: How world leaders were duped over global warming,” and a similar headline online. It detailed assertions by Dr. Bates about temperature data that had been used in the 2015 paper, which provided evidence against the idea that global warming had slowed in the first decade of this century.