Maryland Gov. Martin O'Malley. (Photo by Jonathan Ernst/Reuters)

Maryland Gov. Martin O’Malley (D) took to social media on Monday to urge the U.S. Senate to reject the Keystone XL oil pipeline, saying the country needs to look beyond “smallball choices facing us on energy.”

O’Malley, who is weighing a 2016 White House bid, wrote on Facebook that the pipeline would produce “too much carbon dioxide and not nearly enough jobs” and should be rejected. He also expressed his opposition on Twitter.

The Republican-led House voted last week 252-to-161 to move forward with the project, while a planned Senate vote on Tuesday is expected to be very close. President Obama could also veto the measure.

O’Malley’s posture plays well with environmental groups and positions him to the left of Hillary Rodham Clinton, whom O’Malley would like face for the Democratic presidential nomination and who has not taken a position on pipeline’s construction.

Environmental groups have argued that the pipeline, which would stretch from Canada’s oil sands to the Texas Gulf Coast, would adversely affect climate change.

“We need a jobs agenda that meets our climate challenge — we need solutions that simultaneously reduce carbon emissions and create jobs,” O’Malley wrote on Facebook. “With a bold focus on renewable energy, we can solve the climate challenge, unleash America’s innovative spirit, and re-invigorate American economic dynamism.”