Donnell “Trip” Van Noppen (Dave Getzschman for Earthjustice)

Donnell “Trip” Van Noppen is planning to step down as president of Earthjustice, the largest nonprofit environmental law organization in the U.S., by the end of 2018, according to an announcement from the group Thursday.

Van Noppen, an attorney renowned for his environmental advocacy work, joined San Francisco-based Earthjustice as vice president of litigation in 2005 and stepped up to become its president in 2008. During his tenure at the helm of Earthjustice, which uses the courts to advocate around issues such as climate change, clean water and wildlife conservation, the organization has experienced major growth, both geographically and in the size of its staff.

In the announcement of his departure, Van Noppen called his time as Earthjustice president “the experience of a lifetime” and noted the “extraordinary dedication” to Earthjustice’s mission from its board, staff and supporters.

“Together, we wield the power of the law to protect all that we hold dear: our health, our right to clean air and water, our most sacred lands and precious species and our future survival as a planet,” he said. “I am of course sad to announce my plan to step down from this position, but I do so with the utmost confidence that Earthjustice will continue to thrive.”

Earthjustice’s board and senior staff will conduct a search for Van Noppen’s successor. The organization did not immediately provide comment on Van Noppen’s future departure beyond the initial announcement.

In the last few years, under Van Noppen’s watch, Earthjustice has kept busy in courts and legislatures, using its legal firepower on projects from representing the Standing Rock Sioux in the battle over the Dakota Access Pipeline to defending the federal Clean Power Plan.

George Martin, board chairman of Earthjustice, praised Van Noppen’s work in a statement.

“He has been a tireless leader on litigation strategies and institutional development, and he has spearheaded Earthjustice’s contributions to the environmental movement as a whole,” Martin said. “He has also ensured that the organization continues to thoughtfully and proactively address questions of diversity, equity and inclusion at every level of culture and practice.”

Before joining Earthjustice, Van Noppen worked at the Southern Environmental Law Center, which he joined in 1998. He served as director of the center’s Carolinas Office. Earlier in his career, he was in private practice working on civil rights, employment, environmental and toxic tort cases.