Shipping companies have unveiled plans to reduce their carbon footprint in an effort to counter possible environmental taxes, which are being discussed at the Copenhagen climate summit.

Japan’s NYK Line said it will cut CO² emissions by 70% by 2030 and develop a zero-emissions ship by 2050. The company said it will use a combination of fuel cells and solar and wind energy to reduce emissions and hit targets.

Denmark’s DK Group and Finland’s Wärtsilä Corporation are developing ship engines with air lubrication technology, which run compressed air into the base of the hull to reduce drag and can cut fuel use by 15%.

French container line CMA-CGM said its Christophe Colomb is equipped with an electronic engine and rubberised propeller to save fuel and restrict emissions.

Maersk shipping line said it has adopted technology that pipes cold water from the sea into cooling systems, recycling heat from exhaust pipes back into engines and using slicker paint on hulls.

The company said through slower steaming and better scheduling it aims to reduce carbon emissions by 20% by 2017.