Calgary Herald: Alberta and the federal government rejected a new report Monday that called for a carbon tax and emissions trading system, likely setting up a political showdown at this week’s first ministers conference in Ottawa. Premier Ed Stelmach and his provincial counterparts will meet Friday in the nation’s capital before heading to 24 Sussex Drive for a tete-a-tete with Prime Minister Stephen Harper to discuss the state of the Canadian economy and high-flying loonie. But with a federal …