Judge's sanctions against Michael Mann revive battle over climate defamation case

A Washington, D.C., judge accused climate scientist Michael Mann and his legal team of misconduct during a defamation trial, reigniting a legal fight that has spanned over a decade.

DeSmog reports.


In short:

  • In 2024, Michael Mann won a $1 million jury verdict in a defamation case against two bloggers, but Judge Alfred Irving later reduced the award to $5,000 and imposed sanctions against Mann’s legal team.
  • The judge claimed Mann’s lawyers intentionally misled the court about research grant data, though the team insists the discrepancies were acknowledged and corrected before trial.
  • Mann’s lawyers are asking the court to reverse the misconduct ruling, while critics link the judge’s stance to a broader political trend undermining climate science.

Key quote:

“The current Trump administration is engaging in an aggressive effort to defund and marginalize climate science. In this atmosphere, attacks on climate science and scientists have increased.”

— Robert Brulle, professor of climate science and society at Brown University

Why this matters:

This case reflects the precarious position of climate scientists in the United States, where legal and political forces often shape public understanding of science. Lawsuits like this one have become a battleground over the legitimacy of climate research, especially when scientists challenge powerful industries or ideologies. When courts penalize researchers for procedural missteps — even ones acknowledged and corrected — it sends a signal that speaking out carries serious professional and financial risks. Judge Alfred Irving’s decision to slash damages and accuse Mann’s team of misconduct could embolden those who seek to discredit scientists through litigation rather than scientific debate. At a time when the Trump administration is scaling back climate programs and rolling back environmental rules, these rulings echo a broader push to marginalize and stifle climate expertise.

Related:

A man using a snow blower on a snowy day

‘Exceptionally cold’: How a warming Arctic is pushing the US and Eastern Europe into a deep freeze

Warm Arctic waters and cold continental land are combining to stretch the dreaded polar vortex in a way that sent much of the United States a devastating dose of winter weather.

A helicopter dropping water onto a wildfire with burning trees in the background

Many Amazon climate disasters are missing from official records, study finds

More than 12,500 extreme climate events were registered in the Amazon biome between 2013 and 2023, according to a recent study, but many more events were never recorded.

Two men in suits tallying numbers on a calculator

After decades of deflection, ExxonMobil moves to reshape global climate accounting

For decades, ExxonMobil argued consumers, not oil giants, should take responsibility for fossil fuel pollution. It’s now backing an accounting scheme that moves pollution “liabilities” to buyers’ books.

A view of an Alaskan village on the edge of a body of water

Documenting an Alaska village, before and after the storm that destroyed it

The story of Typhoon Halong’s destruction in Kipnuk adds an exclamation point to long-simmering fears about the future of Alaska coastal villages facing down climate change.
A logging truck on a dirt road next to a forest

Europe gets ‘green energy.’ These Southern towns get dirty air

Wood pellets burned for electricity in Europe are fueling air pollution and health concerns in predominantly low-income towns in Mississippi and Louisiana.

Sailing ship among the icebergs, Antarctica
Credit: Tarpan 74/ BigStock Photo ID: 22516742

A look through a century of Times reporting from Antarctica

Generations of Times journalists have journeyed there with scientists. Their coverage traces humankind’s changing relationship with the most mysterious continent.
Chinese-made BYD Atto 3 electric car showcased at the Paris Motor Show, France 2022.
Credit: VanderWolf Images/ BigStock Photo ID: 466628233

As the U.S. and Canada clash, China stands ready to step in and sell the cars of the future

The Canada-China trade deal should make U.S. automakers worry, but it’s not surprising.
From our Newsroom
Multiple Houston-area oil and gas facilities that have violated pollution laws are seeking permit renewals

Multiple Houston-area oil and gas facilities that have violated pollution laws are seeking permit renewals

One facility has emitted cancer-causing chemicals into waterways at levels up to 520% higher than legal limits.

Regulators are underestimating health impacts from air pollution: Study

Regulators are underestimating health impacts from air pollution: Study

"The reality is, we are not exposed to one chemical at a time.”

Pennsylvania governor Josh Shapiro speaks with the state flag and American flag behind him.

Two years into his term, has Gov. Shapiro kept his promises to regulate Pennsylvania’s fracking industry?

A new report assesses the administration’s progress and makes new recommendations

silhouette of people holding hands by a lake at sunset

An open letter from EPA staff to the American public

“We cannot stand by and allow this to happen. We need to hold this administration accountable.”

wildfire retardants being sprayed by plane

New evidence links heavy metal pollution with wildfire retardants

“The chemical black box” that blankets wildfire-impacted areas is increasingly under scrutiny.

Stay informed: sign up for The Daily Climate newsletter
Top news on climate impacts, solutions, politics, drivers. Delivered to your inbox week days.