If the stage is now set for the climate battle to begin, there is no shortage of combatants. A Center for Public Integrity analysis shows that, by the end of last year, more than 770 companies and interest groups had hired an estimated 2,340 lobbyists to influence federal policy on climate change. That’s an increase of more than 300 percent in just five years, and means that Washington can now boast more than four climate lobbyists for every member of Congress.