Several companies around the world are experimenting with wind-assisted ships, which would reduce fuel consumption at a time where fuel can represent up to 60 percent of the running costs of operating a ship. But another goal is to reduce pollution: the toxic emission volume of the world trade fleet is roughly equivalent to the U.S. one today. In "The new age of sail," New Scientist describes a ship that will be partially pulled by a high-tech kite flying at an altitude of up to 500 meters where winds are more stable than at sea level. The German designers, who tested a prototype last year, estimate that such a hybrid sailing ship would see a 50 percent reduction of its fuel consumption. Danish and Japanese companies are also designing wind-assisted ships.