The Environmental Protection Agency has been told by the US Supreme Court that it's time to determine if greenhouse gases are a danger to public health. If they are, then tailpipe emissions from cars and trucks should be regulated accordingly. A year has passed since the order, but nothing's been done, and despite repeated promises from President Bush, it now appears that won't happen as long as he's in office. Conservative think-tanks and industry lobbyists say the court didn't know that its ruling could shut down the economy. Environmentalists say they'll go back to court. Does inaction represent prudent public policy or foot dragging for special interests?