BONN, Germany — A group of U.S. states, cities, businesses and universities said Saturday they are still committed to curbing global warming even as President Trump’s administration is walking away from the Paris climate accord. But the alliance, which has an economy larger than Japan and Germany combined, says it won’t be able to achieve the necessary cut in greenhouse gas emissions without some efforts at the federal level. “It is important for the world to know, the American government may have pulled out of the Paris agreement, but the American people are committed to its goals, and there is nothing Washington can do to stop us,” former New York City Mayor Michael Bloomberg said at a global climate meeting in Bonn, Germany. Gov.