Why are we constantly trying to prove human influence in extreme weather events when we already know that fossil fuel-driven climate change has fundamentally altered the climate system?
In a Nature Climate Action comment released two weeks ago, my colleagues and I propose a significant normative shift in climate attribution science—and ultimately, in how we talk about climate change. Rather than repeatedly asking and testing for human influence in climate or weather extremes, scientists should begin by assuming that fossil fuel-driven climate change impacts every event to some extent.
Our climate system—the atmosphere, ocean, and land—has been fundamentally changed due to decades of fossil fuel-driven climate change. For example, due to warmer temperatures, the atmosphere can now hold more water, leading to an intensification of the global water cycle. In addition to an expanding Hadley Circulation, there is evidence of a poleward shift of the westerly jet streams, which changes weather patterns over the US. In the oceans, which have absorbed 92% of the heat added to the climate system from fossil fuel-caused warming, more frequent and intense marine heatwaves are occurring globally.
Given humans’ clear role in fundamentally changing the system, my colleagues and I attempt to shift the norms within attribution science and chart out a path that more directly achieves climate action and climate justice initiatives.
What is climate attribution science?
Climate attribution science is a mature sub-field of climate science that has been tested and perfected over the last two decades. For example, extreme event attribution answers the question in many instances, “how much more intense was this extreme event due to fossil fuel-driven climate change?” Or, “how much more frequent will this extreme event become due to fossil fuel-driven climate change?”
Scientists have now published hundreds of attribution studies, many finding conclusive evidence that extreme heat and rainfall, tropical cyclone rainfall, and weather conditions that produce wildfires in the western U.S. are exacerbated by human-caused climate change.
Yet still, scientists, journalists, and media frequently ask after an extreme event, “did climate change contribute to this?” The answer is yes. According to the latest IPCC report, “It is unequivocal that human influence has warmed the atmosphere, ocean and land… climate change is already affecting many weather and climate extremes in every region across the globe.” The emission of heat-trapping gases into our atmosphere has fundamentally changed how our climate system works. We no longer need to ask, “was this influenced by climate change?” We can instead assume there was some influence, and instead ask, “how? And to what extent?” And the urgent question, “what do we do about it?”
Big Oil learned from Big Tobacco
Why are we in this mess to begin with? It all has to do with “doubt” in the science, manufactured by Big Oil. According to a report released by my colleagues, Big Oil knew that the burning of fossil fuels would lead to climate change as early as the late 1950s, but instead of acting on this knowledge to change their business model to reflect the science, they began sowing doubt in the science in order to continue profiting off of the extraction and burning of fossil fuels.
Scientists have been in this position—where an industry spreads lies to confuse people about settled scientific facts—before. In the mid-20th century, a buildup of evidence linking smoking to lung cancer led tobacco companies to deliberately spread misinformation that cast doubt on the established medical science, allowing them to profit off the sale of their product despite known deadly health impacts.
Today, the fossil fuel industry is using the same methods as Big Tobacco, and today’s situation is actually far worse. Fossil fuel-driven climate change was well-understood in the 1980s, and President George H. W. Bush famously pushed for action on the climate crisis, contributing to the formation of the United Nations Framework Convention on Climate Change.
Big Oil responded by deliberately spreading misinformation, including questioning the scientific basis of climate science and citing the economic cost of switching away from fossil fuels without accounting for the costs of climate change itself. This was done through advertorials and the funding and amplifying of junk science, which Exxon and other companies were working to create and spread by the late 1990s.
Why does this matter for attribution science? The fact is that climate scientists are constantly held back by persistent disinformation spread by the fossil fuel industry. A substantial amount of resources and capacity have been spent to replicate and communicate the same research and conclusions that have been well understood for decades, when scientists could have instead been innovating climate science more rapidly.
It’s also clear that advancements in attribution science could strengthen climate litigation. In response, conservative groups are continuing to spread the lie that climate science isn’t settled, and legislators are openly questioning the validity of attribution science in proposed legislation that would grant Big Oil legal immunity.
The future of attribution science
With this NPJ Climate Action comment, we argue for moving beyond repeating well-established conclusions of climate change, which is exactly what Big Oil wants us to do. We don’t need to redo the science that a given extreme heatwave is influenced by fossil fuel-driven climate change when it already occurs in a changed system!
The message here is not just for climate scientists, but also journalists, opinion leaders, and the general public. We should begin all analyses of extreme weather events from the established physical reality that all events occur within a fossil fuel-altered climate system. We no longer need to question if each event was influenced by climate change.
This normative shift enables scientists to focus on opportunities for innovation in attribution science that more directly address equitable climate action. For example, more scientists could shift their focus to improving both impact and source attribution science. Impact attribution answers questions like, “how many more deaths or how much more economic damage resulted from this extreme weather event due to fossil fuel-driven climate change?” Source attribution studies quantify oil and gas producers’ individual contributions to climate trends and extreme events. As litigation pursues accountability for fossil fuel companies, source attribution studies can be key in informing these lawsuits.
As the impacts from fossil fuel-driven climate change continue to accelerate, it is up to scientists, communicators, and the public to break through the disinformation that bad actors continue to spread to slow down scientific advancement and climate action. Updating the norms of attribution science will allow for the science to continue to evolve and effectively respond to the climate crisis. Our climate science needs to be able to shed the dead weight of these tired, fossil fuel-interest-serving arguments, and instead to bring all its energy to helping create a lasting society for future generations.