As climate impacts intensify, so does the legal push to hold polluters accountable, protect vulnerable communities, and enforce environmental laws. And in these legal cases, science is key. Because science can’t present itself on the stand, scientists are essential to give scientific results a voice. But in courts, scientists must be able to communicate their research clearly, responsibly, and persuasively to ensure that scientific information can be understood and applied to the case at hand.
Put another way, a scientist’s role in the courtroom is to translate—to turn complex findings into something that can be understood, trusted, and used to serve justice. The courtroom can be a high-stakes space, where decisions can change lives, redistribute resources, and determine accountability. And while judges and juries are smart, they’re probably not climate modelers, sociologists, economists, or statisticians. That’s where we come in.
Translation is no easy task and increasingly experts who translate their knowledge to advance decision-making in the courts are under attack, but I think it is important to remember that:
- Science belongs in the courts. There is a long history of using science in the courtroom;
- Facts belong in the courts. Despite an onslaught of attacks, climate science is robust and can inform important decision making; and
- Experts belong in the courts. As experts we can learn how to accurately communicate in the courts to ensure that decision makers have access to the best available information.
Science has been used in the courts for centuries
Science didn’t always have a seat at the legal table. Courts traditionally relied on eyewitnesses, assumptions, and arguments about how things work. The idea that someone could testify about something they didn’t directly observe was far from commonplace until the 18th Century.
This changed in 1782 during a British case,Folkes v. Chadd. The case was assessing if a man-made structure had disrupted a harbor’s natural flow. The court called on John Smeaton, a leading engineer of his time, to explain the science of tides and hydraulics. The defense objected because Smeaton hadn’t seen the harbor himself. But, in appeal, the judge made a landmark call that on matters beyond common understanding, the opinions of experts are not just admissible, but essential.
That opened the door, and over the next two centuries, expert testimony has become routine, especially in the United States. But with that change came some challenges. By the late 20th Century, courts were flooded with conflicting experts, often hired to support a side rather than the truth.
In 1993, the US Supreme Court stepped in with Daubert v. Merrell Dow Pharmaceuticals. The ruling gave judges a new role as the gatekeepers of scientific evidence. Judges are now asked to apply the Daubert test to assess if the methods used are testable, peer-reviewed, reliable, and widely acceptable in the scientific community. This was a win for rigor and requires that, as scientists, we can make our methods, and their limits, clear to non-scientists.
Attacks on climate science in the courts
While science has a clear and long history of use in the courtroom, the Trump administration opened the door for the fossil fuel industry to advance its long-standing agenda to undermine climate science. During this administration, there have been numerous attacks that serve to limit the use of climate science to inform legal cases.
The Trump administration’s war on climate science continues to unfold in a calculated sequence, each step deepening the erosion of scientific integrity just when it is needed most in the courts. At a high level, the administration withdrew the United States from the Intergovernmental Panel on Climate Change (IPCC), severing our nation’s formal ties to the world’s most trusted source of climate science.
The administration attempted to replace consensus science with a Department of Energy report that was politically driven and authored by climate skeptics. This report was not peer-reviewed science; it was a weapon, designed to create manufactured doubt and provide cover for regulatory rollbacks. After the Union of Concerned Scientists filed suit over the formation of the report working group, the group was disbanded—but a federal court still ruled the group violated federal law. Last month, Trump’s EPA moved to repeal the 2009 Endangerment Finding, a cornerstone of federal climate policy that used robust science to protect communities. As these attacks weakened the executive branch’s scientific foundation, opponents turned their sights on the judiciary.
Senator Ted Cruz launched a congressional hearing targeting the Environmental Law Institute’s judicial education programs in an attempt to prevent judges from having access to scientific classes to better understand the science of climate change. These probes continue. Republican attorneys general continued this political pressure campaign, culminating in the Federal Judicial Center’s (FJC) decision to remove a comprehensive climate science chapter from its Reference Manual on Scientific Evidence, a critical resource for judges evaluating complex scientific testimony. The removal leaves judges without authoritative guidance at a time when climate litigation is surging. While the FJC removed the chapter, it’s still available through the National Academies.
These actions, taken together, work to delegitimize climate science at every level of government, creating barriers for communities who seek justice through the court.
Clear communication isn’t optional
Science is central to cases on climate liability, environmental justice, and public health. But arguably, its value depends entirely on how it’s communicated. When science communication fails, justice fails. So, what can we, as scientists, do? While there is a lot to learn, here are five tips to help share your science in a legal setting:
1. Speak like a human, not a journal article. As academics, we’re trained to write for peer-reviewed journals that are dense, cautious, and full of caveats. That doesn’t work in court. You need to be clear, concise, and relatable. Replace jargon with plain language. Use analogies—carefully. For example, instead of saying “the anthropogenic signal exceeds the 95% confidence interval,” try “our analysis shows it’s extremely unlikely this warming happened by natural causes alone, like flipping a coin and getting heads 19 times out of 20.” It’s the same concept, but the second is far easier to understand.
2. Be thoughtful about communicating uncertainty. For researchers, expressing uncertainty is a sign of credibility that shows we’ve tested our results, accounted for error, and understand the limits of our data. But in the courtroom, the word “uncertain” often corresponds to doubt, hesitation, or unreliability. Be honest and explain your findings in terms the court can use, emphasizing confidence, consistency, and the weight of evidence. Also, know the standard of evidence required in the case and how your uncertainty measures relate to that. You can’t just share your results: You need to translate them for a legal audience, and help them see that uncertainty is part of good science, not a reason to dismiss it.
3. Prepare to be challenged—because you will. Legal settings are adversarial. Opposing counsel will test you, sometimes aggressively. They’ll look for inconsistencies, gaps, or moments of confusion. Preparation is everything. Practice explaining your work under pressure. Anticipate tough questions. Know the limits of your expertise. And if you don’t know an answer, say so. Every PhD has gone through an oral defense. If your dissertation defense was anything like mine, you can handle a courtroom.
4. Be accurate but concise. Scientists are trained to lecture, to unpack every nuance, to write like we’re defending a thesis. But in court, clarity beats comprehensiveness. If you attempt to deliver an entire thesis on the stand, you’ll lose everyone’s attention. Judges and juries need the core of what you know, not the full arc of how you got there. Focus on the key findings, deliver them plainly, and stop when you’ve made the point. Brevity isn’t dumbing down, it’s respect for the listener.
5. Understand why your science is relevant. Before you testify, ask the lawyer: What specific question does the court need answered? Your job isn’t to broadly teach your science, it’s to address the issue at hand. Stay focused. Everything you say should connect back to the legal question. It’s helpful to think about why a scientific concept is relevant to the court, like we did in our glossary of scientific terms for a legal audience.
Be ready when science is called to the stand
Science has a critical role to play in the courtroom. As climate litigation continues to grow, the need for well-prepared, clear, and credible scientific voices has never been greater. The challenges are real, but so are the opportunities. By improving how we communicate experts can help ensure that courts have access to the best available science, presented in a way that’s both accurate and understandable.
If you’re interested in stepping into this space or strengthening your skills, consider connecting with the Science Hub for Climate Litigation. Through skill shares, resources, and community, the Science Hub helps experts like you engage effectively in legal settings so that when science is called to testify, you are ready and the facts are heard.