"Iraq is developing a long-range ballistic missile system that could carry weapons of mass destruction up to 700 miles." Iraq is progressing towards "dirty bombs that spew radioactivity, mobile bio-weapons facilities, and a new long-range ballistic missile." An Iraqi defector "tells of work on at least 20 hidden weapons sites." It is an "undisputed fact" that September 11 attacker Mohamed Atta met with Iraqi intelligence officers in Prague.

Those claims appeared in mainstream newspapers during the lead-up to the invasion of Iraq in 2003. All those claims were false. The nonexistence of Weapons of Mass Destruction (WMDs) in Iraq immediately prior to the invasion and the absence of links between Iraq and al-Qaida eventually became the official U.S. position with the Duelfer Report and the report of the U.S. Senate Select Committee on Intelligence.

A decade later, those media failures are relevant not only because of the war's six-figure death toll and because the Iraqi per capita GDP has so far failed to return to prewar levels, but also because they remind us that the media, including highly reputable newspapers, can sometimes get things quite wrong.

A similar media failure is arguably under way this very moment with regard to climate change. The most recent report of the Intergovernmental Panel on Climate Change (IPCC) concluded with near certainty that human economic activity is responsible for ongoing global warming, and some of the largest insurance companies on the planet have blamed the increase in losses from extreme weather events to climate-related disasters.

This has not kept some newspapers from reporting that Arctic ice is "recovering", a rather adventurous claim in light of the fact that the Arctic has lost 40% of its ice cover since 1980 and that ice extent is now lower than during several millennia preceding 1980. A recent quantitative analysis of climate coverage in the Australian media confirmed that misreporting of the science is widespread.

There are some interesting similarities and differences between the media failures involving Iraqi WMDs and climate change.

One notable difference between pre-invasion reporting on Iraqi WMD and climate change is that, in contrast to the near-hegemony of war-supporting reporting (at least in the U.S.), the public has a broader choice now when it comes to climate change: While there is a large supply of disinformation that threatens the public's right to being adequately informed, there is also no shortage of actual scientific information, both in the mainstream media and beyond.

The diversity of sources empowers the public to select their information wisely, but it also provides a playing field for the dominant influence of people's cultural worldviews or "ideology", which can override even education. People whose core personal values are threatened by possible responses to climate change, such as a price on carbon or regulatory measures, are known to rely on media sources that are more likely to create confusion about climate change than disseminate scientifically accurate information.

Worldviews may also explain another cognitive difference between Iraq and climate, which concerns the asymmetry in the evaluation of evidence in the two cases. In the case of Iraqi WMDs, we now know that the media—and politicians among the "Coalition of the Willing"—used weak and insufficient evidence to call for a pre-emptive war against a largely imaginary risk. In the case of climate, by contrast, a mountain of scientific evidence pointing to a risk far greater than that posed by Saddam Hussein is ignored, and mitigative action refused, on the basis of similar worldviews.

There are also similarities. In both cases, a link can be drawn between misinformation and the likelihood of warfare. Together with colleagues, I reviewed the literature on this relationship in a recent paper using the Iraq War and climate change as case studies. We report a reasonably clear link between the acceptance of misinformation and support for the Iraq War, both before and after military action commenced. In one U.S. study, belief in misinformation—that is, the existence of WMDs—was the most powerful predictor of support for the Iraq war. Belief in WMDs quadrupled the likelihood of support for the war.

There is also increasing evidence of a link between climate change and violent conflict, with a recent study suggesting that the risk of violent conflict may increase globally by upward of 30% by 2050 if human-caused warming continues unabated. The link between climate change and conflict is of a statistical nature and not entirely certain, but it should alert us to the possibility that any further delay of climate mitigation, whether based on dissemination of misinformation or other factors, may cause unnecessary future deaths.

Another ironic similarity is that the same newspapers and the same journalists who beat the war drums a decade ago are now also frequently misrepresenting the risk the world is facing from climate change. After WMDs failed to materialize in post-invasion Iraq, this led to occasional anguish among journalists who regretted that they used "'evidence' now known to be bogus" to push for war. The lethal fallout from misinformation a decade ago primarily affected the people of Iraq. The fallout from misinformation about climate change is likely to affect us all.

Stephan Lewandowsky is a Professor of Cognitive Psychology at the University of Bristol and received a Wolfson Research Merit Award from the Royal Society in 2013. On Twitter he is @STWorg. His research examines the distinction between skepticism and denial, misinformation, and the role of uncertainty in people's thinking about climate change.