Environmentalists on Wednesday accused former Secretary of State Rex Tillerson—who served as CEO of ExxonMobil from 2006 to 2016—of continuing to lie about the fossil fuel giant's approach to climate change during his testimony in the historic New York v. Exxon trial.

The landmark securities fraud case, brought by New York Attorney General Letitia James, alleges that Exxon knowingly deceived shareholders about the financial costs of the climate crisis.

Tillerson denied that charge during his testimony, insisting that Exxon knew the climate crisis "was a real issue" and took it seriously.

"The demand to make Exxon pay for climate chaos is only getting louder."

—Dominique Thomas, 350.org

"We would be misinforming ourselves," Tillerson said when asked if Exxon had an incentive to downplay the costs of climate change.

Lindsay Meiman, senior regional communications specialist at 350.org, strongly rejected Tillerson's account.

"Just now, at the New York County Supreme Court, former Exxon CEO Rex Tillerson spewed more deception claiming Exxon executives took the risks of climate change seriously, yet, in the same breath, denied the need to keep fossil fuels in the ground," Meiman wrote in an email to supporters.

"Absurdly, during his tenure at Exxon, Rex had a secret alias: Wayne Tracker," said Meiman. "Tillerson used his Wayne Tracker pseudonym to communicate all things related to climate change. He then left his Exxon post to serve as Trump's Secretary of State before getting the boot from the increasingly oily and corrupt administration. This guy is as shady as it gets."

Tillerson was not asked about the "Wayne Tracker" alias during his testimony.

Today Rex Tillerson denied in court that ExxonMobil committed fraud by concealing the financial impact of climate change from shareholders. We all deserve justice for Big Oil's crimes against our communities & climate. Tell Congress to #MakeThemPay now: https://t.co/OTJS9cNtfc — 350 dot org (@350) October 30, 2019

The Guardian reported Wednesday that the New York attorney general's office "has sought to cast Tillerson as a central figure in the securities fraud case, with Kevin Wallace, acting head of the attorney general's investor protection bureau, telling the court last week that the former chief executive was 'deeply involved' in working out the impact of climate science upon Exxon's business prospects."

Dominique Thomas, 350.org's northeast regional organizer, said Tillerson "should get used to" appearing on the witness stand in climate accountability cases.

"As wildfires rage across California and the West, it's momentous to see Exxon's former CEO in court, on the witness stand, testifying to his role in lying to investors about climate-related risks," said Thomas. "The demand to make Exxon pay for climate chaos is only getting louder."