Growing concern about climate change has led states and cities to adopt new policies to try to conserve energy and reduce emissions of carbon dioxide and other greenhouse gases. California recently adopted new rules that aim to reduce such gases by 30 percent by 2020, while a cap on carbon emissions in the Northeast took effect Jan. 1. But critics say the efforts are more symbolic than substantive, pushing real sacrifices far off into the future. Many business groups, meanwhile, complain that the new rules will increase the cost of energy and hurt the economy — despite current promises that a "Green New Deal" can create jobs. The Obama administration promises to be far more aggressive in addressing global warming than the skeptical Bush White House. Even though the issue is coming to the fore in Washington, states and cities that have filled the policy vacuum in recent years pledge to stay vigilant in addressing the issue.