The Niskanen Center is a right-leaning 501(c)(3) environmental advocacy organization with ties to left-wing environmental groups.
ExxonMobil/Suncor Lawsuit (2018)
In April 2018, the City of Boulder, Colorado and County of San Miguel, Colorado filed a lawsuit against oil and natural gas companies ExxonMobil and Suncor, accusing them of being “fossil fuel-producing corporations” which negatively impact the climate.  The Colorado communities were represented in the lawsuit by a joint climate group which included Hannon Law Firm,  a group that litigates environmental lawsuits and whose founder Kevin Hannon served as chief outside legal counsel, the environmentalist nonprofit EarthRights International, and the Niskanen Center. The joint climate group claimed that ExxonMobil and Suncor were culpable for over $100 million in climate damages—including wildfires, flooding, road maintenance, landscaping, and individuals work efficiency .
According to two environmental experts, Randal O’Toole and Robert Bradley Jr., individuals who had known William Niskanen (the Niskanen Center’s founder), the Center’s involvement in the lawsuit went directly against the memory of Niskanen and what he believed with regards to climate-policy. William Niskanen stated that “the case for a global warming treaty is shockingly weak” and also that he had “never bought into climate alarmism.”