The campaign targets Reps. Rodney Davis (R-Ill.), Dan BenishekDan BenishekRepublican groups launch final ad blitz in key House battlegrounds Tea Party class reassesses record Michigan Republican to retire MORE (R-Mich.) and Mike Coffman (R-Colo.) for their opposition to various green policies. The ads, while individually tailored for each lawmaker, all suggest they're opposed to expanded environmental protections because they're beholden to the oil industry.

"Congressman Coffman is so extreme he sides with Big Oil," the narrator says in the ad targeting Coffman.

The new ads are part of a $2 million campaign LCV launched last week targeting climate change skeptics. They're also hitting Sen. Ron JohnsonRon JohnsonTrump should work with Congress to block regulations on prepaid cards Five reasons to worry about the ShadowBrokers hack Border Patrol could drop polygraph requirement for new agents: report MORE (R-Wis.) with television ads.

Though the ads are backed by the group's advocacy arm, rather than its PAC, it believes targeting climate change skeptics in Congress could be a winning argument in 2014.

Last election cycle, the group launched a $1.5 million effort to defeat what they called the "Flat Earth Five," five lawmakers who were skeptical of climate change science. All but one were defeated.