WASHINGTON — President-elect Joseph R. Biden Jr. is expected to pick Gina McCarthy, the former administrator of the Environmental Protection Agency under President Barack Obama and the architect of some of his most far-reaching regulations to limit greenhouse gas emissions, to serve as senior White House adviser on climate change, according to three people close to the Biden transition team. As White House adviser, Ms. McCarthy will coordinate domestic climate policies across the United States government, playing a central role in helping Mr. Biden make good on his campaign promise of putting the United States on track to reach carbon neutrality before 2050. Mr. Biden also intends to name Ali Zaidi, the deputy secretary for energy and environment for New York State, who helped write Mr. Biden’s climate plan, as Ms. McCarthy’s deputy. 