The Obama administration is warning Congress that if it doesn't move to regulate greenhouse gases, the Environmental Protection Agency will take a "command-and-control" role over the process in a way that could hurt business. The warning, from a top White House economic official who spoke Tuesday on condition of anonymity, came on the eve of EPA Administrator Lisa Jackson's address to the international conference on climate change in Copenhagen, Denmark. Jackson, however, tried to strike a tone of cooperation in her address Wednesday, explaining that the EPA's new powers to regulate greenhouse gases will be used to complement legislation pending...