What do the Province of BC and the County of Multnomah in Oregon have in common? Both are suing a global consultancy, McKinsey and Company, for having contributed to deaths through misinformation campaigns. Both cases raise profound questions about the legal responsibility for consultants and PR companies that fashion corporate strategies that mislead the public and lie about dangerous products.
BC is suing McKinsey for its role in marketing highly addictive and dangerous opioids, leading to drug-related deaths, while Multnomah is suing for the company’s role in the strategies used by fossil fuel companies to undermine public confidence in climate science and to oppose the development of alternatives to fossil fuel energy, contributing to deaths during the heat dome in 2021 (which also caused many deaths in BC).
Earlier this month, the BC Supreme Court certified the Province’s case against McKinsey as a class action, ruling that (among other issues) there may be evidence to connect McKinsey’s role in misinformation (misrepresentations) about the safety of opioids to the deaths and other injuries that occurred in BC. This court decision builds on an earlier January 2025 decision in a related lawsuit against pharmaceutical companies, which held that the legal issues raised by the Province in this lawsuit are “arguable” – and can be considered by the courts.
encouraging to those who would like to see fossil fuel companies – that have lied about their products and worked to prevent alternatives – sued in BC courts. And it raises questions about whether McKinsey and other companies and lobby groups that have spread misinformation should be included in such a case.
Who is McKinsey?
McKinsey is an international company that provides advice to corporations and governments on a wide range of strategy and policy matters. In one of the more hilarious and accessible commentaries on this company and its role in the international world of business, comedian John Oliver explains:
[McKinsey has] been around for nearly a century advising both big companies and government agencies on how to fix their most complex and urgent problems. … Firms like McKinsey sell themselves as can-do experts who can come in, provide an outside perspective, and fix whatever ails a company. …
McKinsey is massive, and it’s ubiquitous. It has offices in at least 65 countries and an annual revenue estimated at 15 billion dollars. …
And the truth is, McKinsey’s reputation has taken a bit of a knock in recent years.
It’s found itself under scrutiny for everything, from exacerbating income inequality, to helping market dangerous products, to enabling authoritarian regimes.
And former employees have pointed out that for all its talk of making the world “a better place,” it’s worked for some of the planet’s biggest polluters while getting hundreds of millions of dollars in return.
A similar review is found in the book, When McKinsey comes to Town, as summarized by the Washington Post:
The authors expose the firm’s unsavory work with fossil fuel companies, cigarette-makers, opioid distributors, regulatory agencies and autocratic regimes. In a masterful work of investigative journalism building on their reporting for the New York Times, [Walt] Bogdanich and [Michael] Forsythe pierce through McKinsey’s “culture of secrecy” — a process they describe as “akin to chasing shadows” — to unearth conflicts of interest, corruption, hypocrisy and strategic blunders that read like a prosecutor’s indictment.
The allegations in both the BC and the Multnomah lawsuits are that McKinsey worked with many of the companies responsible for the products that caused the opioid epidemic and the climate crisis respectively and advised them on their strategies to lie about their products and avoid public scrutiny and regulation. In the case of opioids, the company has been previously sued in the U.S., ultimately settling for almost US$600 million for its role in promoting opioid sales.
Here’s how Multnomah County puts it in their statement of claim (as yet unproved):
McKinsey has coordinated and participated in a deliberate misinformation campaign to downplay and/or outright deny the causal relationship between the use of its fossil fuel clients’ products and climate harms, thereby leading to an increase in the demand and consumption of the fossil fuel products, and the severity of extreme weather events …. McKinsey’s contribution to, and deception is individually and collectively (with the other Defendants) a cause of enormous harm …
McKinsey has worked with many of the largest Canadian oil sands companies, interestingly while also advising the Canadian government on clean energy.
Deception and evidence in BC climate litigation
In 2022 the Intergovernmental Panel on Climate Change explicitly identified misinformation campaigns organized by “vested economic and political interests” as a key factor in delaying action on climate change, by fostering “misperceptions of the scientific consensus, uncertainty, disregarded risk and urgency, and dissent (high confidence).” The history of misinformation campaigns by the oil, gas and coal industries goes back decades and is well documented in books like Geoff Dembicki’s The Petroleum Papers or John Vaillant’s Fire Weather.
A company that knowingly sells a harmful product and engages in active misinformation or conspiracy to keep consumers buying that product (and to discourage government from measures that would slow sales) can be sued by those harmed as a result. And that bolded text is part of what a lawsuit against fossil fuel companies (or against McKinsey) for contributing to climate change will have to prove.
Fossil fuel companies and their enablers like to imply that the solutions to the climate crisis have not been thwarted by their past misinformation and lobbying efforts, but rather by technological challenges with developing non-polluting alternatives. Meanwhile, current misinformation is defended as freedom of speech, with oil and gas companies and their enablers complaining about recent amendments to the Competition Act that make it illegal for companies to advertise the environmental benefits of their products without being able to back their claims up with credible studies.
But there is lots of evidence that, if not for the deception of these companies (and arguably the companies like McKinsey that supported them), the world would not be as hot now, and clean electric alternatives to polluting technologies would be more widely available.
From a legal standpoint, the question is what type of evidence can lawyers bring forward to prove that a particular group of plaintiffs was harmed by misinformation? Legal theorists Jessica Wentz and Ben Franta have examined, in their paper Liability for Public Deception: Linking Fossil Fuel Disinformation to Climate Damages:
… how tort plaintiffs can establish a causal nexus between public deception and damages, drawing from past litigation, particularly claims filed against manufacturers for misleading the public about the risks of tobacco, lead paint, and opioids. A key finding is that courts may infer public reliance on false and misleading statements using multiple lines of evidence, including information about the scope and magnitude of the deceptive communications, defendants’ internal assessments of the efficacy of their disinformation campaigns, acknowledgements of intended reliance made by defendants, expert testimony on the effects of disinformation, public polling data, and more.
In BC’s opioids case, Justice Brundrett confirmed that BC’s courts are open to hearing expert evidence linking misinformation campaigns to increased use of harmful products, and therefore increased harm to plaintiffs. Dr. Bryce Ward, a specialist in health care costs called by the Province, outlined approaches to comparing actual opioid use in the province against a counter-factual world in which the misinformation did not occur. Based on the information provided, this approach seems to be similar to the Climate Attribution studies that can link greenhouse gas emissions to particular climate impacts.
Similarly, in the January decision, Justice Brundrett found that there were credible methodologies related to the pharmaceutical industry defendants in the case that “can be used to determine whether the defendants’ conduct caused an increase in the sale and/or use of Opioid Products in Canada during the Class Period, and to quantify that increase.”
The two rulings in the case do not guarantee that the Province will be able to prove the causal connection between the defendants’ actions and increased opioid addiction in BC, and McKinsey can still raise its own expert objections to the proposed evidence. However, the judge accepted that at this preliminary stage the Province has “a realistic prospect of establishing general causation” based on “a sufficiently plausible method to test causation-related common issues.”
Conclusion
We are not suggesting that the BC local governments considering suing fossil fuel companies for climate costs should sue McKinsey as well. Nor are we suggesting that the BC Supreme Court decision certifying the action against McKinsey provides a definitive answer about what types of evidence will need to be presented in a climate damages case.
However, the class action against McKinsey and opioid manufacturers is of great interest, and encouraging, to those who would like to see fossil fuel companies bear some responsibility for their deception and their sale of harmful products. Both the preliminary decisions we have so far, and future decisions as the case unfolds, will provide insights into how the Canadian courts are likely to view misinformation strategies in climate cases.
