Agence France-Presse: The United States has to lead the global fight on climate change by breaking with business-as-usual and setting tough standards for the amount of greenhouse gases it emits into the atmosphere, US scientists said Wednesday. In one of three multi-hundred-page reports on climate change by the National Research Council, scientists said the United States should set a budget that would limit greenhouse gas emissions to a total of between 170 and 200 gigatons of carbon dioxide equivalent …