A new report by the International Council on Clean Transportation (ICCT) shows that the fuel efficiency of new aircraft has barely improved since 2000. The ICCT report also notes that new aircraft fuel efficiency has improved substantially in only two of the last five decades; fuel costs alone are not sufficient to stimulate increased aircraft efficiency; and the report argues that an international carbon dioxide standard for all newly built and future aircraft is needed. Friends of the Earth's transport campaigner Richard Dyer said: "This report shows that aviation industry claims about the rate at which planes are getting greener are pie in the sky and cannot be trusted. "Aviation is a significant and growing source of carbon emissions worldwide. We cannot allow expensive new runways to be built on the hope that some super-green aircraft technology may come along in future."