equivalent of removing 50 million automobiles equivalent of removing 50 million automobiles equivalent of removing 50 million automobiles marine traffic equivalent of removing 50 million automobiles equivalent of removing 50 million automobiles equivalent of removing 50 million automobiles means carbon emissions and other pollutants equivalent of removing 50 million automobiles equivalent of removing 50 million automobiles equivalent of removing 50 million automobiles equivalent of removing 50 million automobiles