Democratic presidential nominee Joe Biden is filling out his transition team, adding staff and advisers to prepare the transition of power, should he defeat President Trump in November.

The team includes a pair of key advisers who have played major roles in developing Biden’s climate change and clean energy policies: Cecilia Martinez, executive director at the Center for Earth, Energy and Democracy and a University of Delaware research professor, and Lonnie Stephenson, president of the International Brotherhood of Electrical Workers.

The four co-chairs, 15 advisory board members and eight staff members announced Saturday are a major addition to the team led by Ted Kaufman, a longtime political adviser to Biden. The team previously had only a handful of members.