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:

Man in yellow safety vest standing under a building roof being built

As tech companies race to build data centers, communities are pushing back

Concerns about electricity bills and local impacts are fueling bipartisan opposition to the massive data centers that power the digital economy, from cloud services to AI chatbots.

Two men wearing orange safety vests standing in front of piles of coal

Carbon capture, 'rare earth' from coal among projects poised to get $11.7M in Wyoming state grants

Wyoming is seeking public comment on three proposed grants, including $6 million to coal giant Peabody Energy to sift critical minerals from the state's coal.

An aerial view of a wetlands area with green fields and trees in the background

Inside the polarizing plan to stash carbon in a California wetland

A proposal to store carbon dioxide deep below a restored Bay Area wetland is testing how — and where — California pursues climate solutions.
A helicopter hovering over a wildfire

'Our bodies bear the cost': Patagonia's firefighters battle blazes and austerity in ancient forest

Wildfires are still tearing apart the drought-stricken region of Patagonia, ravaging its once-pristine forests.
Aerial photo of coal-fired power plant
Credit: airphoto.gr/BigStock Photo ID: 4550715

‘It’s sick’: Trump administration uses mascot called ‘Coalie’ to push dirtiest fossil fuel

Cartoon lump of coal with giant eyes was spotlighted by US interior secretary in X post saying: ‘Mine, Baby, Mine!’
A row of solar panels with the city of Shanghai in the background

China to see solar capacity outstrip coal capacity this year

The China Electricity Council says that, by the end of 2026, wind and solar will account for nearly half of China’s power capacity.

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.