Patrick W. Dennis is a partner in the Los Angeles office of Gibson, Dunn & Crutcher. He is a member of the Environmental Litigation and Mass Tort Practice Group. Pat has extensive experience representing clients in general manufacturing, energy, banking, aerospace, real estate, construction, electronics, oil and gas, cement making, and lead recycling in a wide range of environmental matters. He has substantial experience in the following areas:
- Toxic Tort Litigation
- CERCLA Cost Recovery Litigation
- Defense of Environmental Enforcement Actions by Public & Private Parties
- Complex or Large Transactions with Environmental Issues
- Environmental Laws and Regulations Counseling
Pat is consistently named among the nation’s leading environmental law attorneys. Lawdragon includes him in its 2024 Green 500: Leaders in Environmental Law guide, the fourth consecutive edition of the guide in which he is recognized. Who's Who Legal recognizes Pat in its 2024 Thought Leaders: USA guide, which features lawyers with “vast expertise and experience advising on some of the world’s most significant and cutting-edge legal matters,” and the “ability to innovate, inspire, and go above and beyond to deliver for their clients.” He is also recommended for outstanding work in environmental law in Who’s Who Legal’s Environment & Climate Change guide. Since 2020, Pat has been included by Legal 500 US as a member of the “Hall of Fame” for Environmental Litigation, most recently being honored in 2024. In 2019, and all years prior since 2009, he was nationally ranked as one of just ten “Leading Lawyers” in Environmental Litigation by Legal 500 US. For the past 21 years Pat has been ranked by Chambers USA, often in the Band One category, and for 2024 he is the “Senior Statesman” for California Environmental Law. He has also been selected by his peers for inclusion in The Best Lawyers in America© for Environmental Law and Environmental Litigation. In 2017, he was listed in Expert Guide’s Energy and Environment guide as a leading practitioner in Environmental Law. From 2012 to 2014, Best Lawyers named him Los Angeles Litigation – Environmental “Lawyer of the Year.” Pat received the 2016 CLAY (California Lawyer Attorney of the Year) award in the Real Estate and Development category for his role in the redevelopment of the Hollywood Park racetrack into a world class football stadium to house the Los Angeles Rams for their return to Los Angeles.
In 2009, Pat was elected to the exclusive American College of Environmental Lawyers by his peers. He was also a Chair and founding member of the Los Angeles County Bar Association Environmental Law Section. Between 2017-2019, Pat was the Chair of the Board of Trustees for the California Science Center Foundation.
Among other successful appellate arguments, Pat represented (1) the Atlantic Richfield Company in the Ninth Circuit Court of Appeal decision reported at Wilshire Westwood Associates v. Atlantic Richfield Corporation, 881 F.2d 801 (1988) (excluding refined petroleum products from CERCLA coverage under the so-called “petroleum exclusion”); (2) the Climate Action Reserve in the California Second Appellate District decision reported at Our Children’s Earth Foundation v. California Air Resources Board, 234 Cal. App. 4th 870 (2015) (upholding the validity of the offset protocols for voluntary carbon emission reductions as part of California’s landmark Greenhouse Gas cap and trade regulations); Philip Morris USA in the trial court and appeal in Aranda v. Philip Morris USA Inc., 183 A.3d 1245 (Del. 2018) (establishing a new and more rigorous test for fórum non conveniens in Delaware by Delaware’s Supreme Court).
He received a B.S. (Civil Engineering – 1976); M.S. (Mechanical Engineering – 1978); and a J.D./MBA (1982), all from the University of California, Los Angeles. Pat has practiced exclusively in the environmental law area since graduating from law school.
Capabilities
- Environmental Litigation and Mass Tort
- Administrative Law and Regulatory Practice
- Transnational Litigation
- Trials
Credentials
Education:
- University of California - Los Angeles - 1982 MBA
- University of California - Los Angeles - 1982 Juris Doctor
- University of California - Los Angeles - 1978 Master of Science
- University of California - Los Angeles - 1976 Bachelor of Science
Admissions:
- California Bar