Al Gore yesterday chose as his running mate Sen. Joseph Lieberman (D-Conn.), a strong environmental advocate who has earned a 95 percent rating from the League of Conservation Voters over the course of his Senate career. Lieberman cosponsored the 1990 Clean Air Act; introduced legislation in 1991 to give citizens more information about pesticide dangers; and has advocated measures to curb climate change, raise fuel-efficiency standards for vehicles, and give wilderness protection to the Arctic National Wildlife Refuge. The Sierra Club called the Gore-Lieberman duo “the most pro-environment ticket in history.” Meanwhile, the Republican National Committee is spending $3.7 million to run an ad in 17 battleground states that criticizes Gore for allowing zinc mining on property he owns, accusing the veep of being hypocritical on environmental issues.