A climate scientist’s legal win just got flipped on its head

Michael Mann, the climate scientist famous for his “hockey stick” graph, won a $1 million defamation case — but a judge has now slashed the award, sanctioned his lawyers, and ordered him to pay over $500,000 in legal fees.

Dino Grandoni reports for The Washington Post.


In short:

  • Mann initially won a defamation case against two conservative commentators who falsely accused him of academic fraud, comparing his climate research to child molestation.
  • A judge has now ruled that Mann’s lawyers misrepresented financial damages, reducing his award and ordering him to pay legal costs for National Review, one of the publishers of the defamatory content.
  • Mann’s legal team plans to appeal, arguing the original defamation ruling remains valid and that the court made significant legal and factual errors.

Key quote:

[Mann] “believes that the court committed errors of fact and law and will pursue these matters further.”

— Peter J. Fontaine, one of Michael Mann’s attorneys

Why this matters:

Mann’s case is a stunning reversal in a proceeding that was supposed to be a victory for scientists fighting back against disinformation. While the original ruling confirmed he was defamed, the reversal raises concerns about how courts handle cases involving scientists facing politically motivated attacks and could have a chilling effect on researchers speaking out against disinformation.

Read more:

Climate scientist Michael Mann takes his critics to court

An illustration of a house covered in a folded $100 bill

LA fire survivors got a rude surprise that could hit more Americans

Many home insurance policies don’t cover the full cost of rebuilding after a disaster, a problem that’s set to grow along with the impacts of climate change.

A view of a road in Alaska with an oil pipeline alongside it

Proposed surcharge on oil would help pay for responses to climate-related disasters in Alaska

A new bill proposes establishing a surcharge to help cover the mounting costs of Alaska disasters like landslides and floods.
A research ship with computers and crew
Credit: NOAA/Unsplash

High Seas Treaty takes effect, giving the open ocean real protection

The high seas used to be the wild west of the ocean, but a new treaty could finally bring oversight.
ship floating on ocean heading to ice burg

New map reveals landscape beneath Antarctica in unprecedented detail

Scientists believe the map could shed light on how Antarctica's vast ice sheet will respond to climate change.
The interior of a burned bulding

Homes that survived the 2025 L.A. fires are still contaminated

Testing of homes in communities surrounding the Eaton and Palisades fires has found dangerous levels of lead and asbestos — even after remediation.
Smiling people with signs marching in support of science.
Credit: Vlad Tchompalov/Unsplash

The state of science, one year on

How the Trump administration is redefining the way science is practiced and perceived in the United States.

EPA head Lee Zeldin at Turning Pint USA event
Credit: gage Skidmore/ https://www.flickr.com/photos/gageskidmore/ https://creativecommons.org/licenses/by-sa/2.0/

Three things to watch in EPA’s endangerment repeal

The agency is close to finalizing its rollback of the endangerment finding. Legal experts say its success could hinge on these details.
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.