New York Times: When the Washington Nationals’ season opened in March, the team unveiled a stadium any environmentalist could love – the country’s first certified green major professional sports stadium, with energy-conserving lights and water-conserving plumbing. Now, the team is the focus of protests from environmentalists who say their issue is not with the stadium, but with the Nationals’ advertising relationship with the oil giant ExxonMobil. The company’s logo appears prominently on the …