If the leaked documents from research submitted for the Interanko report are to be believed , the shipping industry 's contribution is more than twice the amount previously believed ( 600 million tons ) -- which would mean ships emit as much as 1.2 billion tons of greenhouse gases a year . Shipping is more harmful than previously thought . EPA put emissions at as much as 1.2 million tons . More than 90 % of global market served by shipping industry . More regulation needed , say environmental groups suing EPA .
Shipping is more harmful than previously thought . EPA put emissions at as much as 1.2 million tons . More than 90 % of global market served by shipping industry . More regulation needed , say environmental groups suing EPA .