Climate deniers have garnered far more media attention than prominent climate scientists over the years, fuelling public confusion and slowing the response to global warming, researchers reported Tuesday.
From 2000 through 2016, hundreds of academics, business people and politicians who doubted global warming or attributed rising temperatures to "natural" causes got 50 percent more ink than an equal number of top scientists, according to a study in Nature Communications, a peer-reviewed journal.
Even in a more select group of mainstream English language news outlets with high standards of evidence -- from the New York Times and The Guardian to The Wall Street Journal and the Daily Telegraph -- sceptics were still cited slightly more often.
In reality, there has long been overwhelming agreement among climate scientists that global warming -- caused mainly by burning fossil fuels -- poses a major threat to civilization and much of life on Earth.
An increase of only one degree Celsius had triggered rising seas and a crescendo of deadly extreme weather, and Earth is on track to heat up another three degrees by century's end.
"Climate change contrarians have successfully organized a strong voice within politics and science communication," noted the authors, led by Alexander Petersen at the University of California at Merced.
"Such disproportionate media visibility of contrarian arguments and actors misrepresents the distribution of expert-based beliefs," they continued.
"It also undermines the credible authority of career climate change scientists and reinforces the trend of climate change contrarians presiding over public scientific discourse."
Over the last year, public concern over global warming has grown dramatically, sparked in part by an October UN report warning that only a wholesale overhaul of the global economy and consumption patterns can forestall climate chaos.
In Europe, green parties running on a platform of climate action gaining nearly two dozen seats in EU parliamentary elections. Climate protesters drawing from the civil disobedience playbook of Marin Luther King and Gandhi, meanwhile, have spilled into the streets.
- Sowing doubt -
In the United States, a call for climate action has become a litmus test among Democratic candidates for president, and many young people have rallied around the legislative initiative known as the Green New Deal.
A handful of western governments have pledged to slash carbon emissions to "net zero" by mid-century.
But even today, established media continue to provide platforms for dubious or discredited assertions about global warming.
Last week, for example, US business magazine Forbes published an article on its website entitled "Global Warming? An Israeli Astrophysicist Provides Alternative View That is Not Easy To Reject".
The "alternative view" -- that warming is caused by the Sun and not CO2 emissions -- is thoroughly discredited, and the magazine was compelled within hours to remove the piece.
In testimony last month before the US Senate that took on confessional tones, long-time Republican Party strategist Frank Luntz revealed a key moment nearly 20 years ago in the campaign to blunt action against global warming.
"You need to continue to make the lack of scientific certainty a primary issue in the debate," he told party operatives in a memo during George W. Bush's first term in office.
The disquieting term "global warming", he further suggested, should be replaced with "climate change".
"I'm here before you to say that I was wrong in 2001," he told a Senate committee.
In the new study, Petersen and colleagues scanned 100,000 news items published from 2000 through 2016 for bylines, citations and mentions of 386 scientists, and 386 "contrarians".
"Tallying across all media sources we find climate change contrarian media visibility to be 49 percent greater than climate change visibility," they wrote.
The imbalance was made worse by the amplifying effect of social networks such as Facebook and Twitter, they added.