There are three types of emissions from ships:

   ​Carbon dioxide - producing climate change

   Sulfur ​oxides - producing acid rain

   ​Small particles - causing poor health and death

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Scientists at the University of California at San Diego found that ships approaching or in port can account for almost half of the fine sulfate particles found over coastal southern California. 

CO₂ produced by shipping

Shipping produces 5% of the world's CO₂. It is not included in the Kyoto protocol.

Aircraft make up 2% of the total CO2 emissions and they are not part of the Kyoto protocol either.

At a typical 85% occupancy, the energy consumption of a tourist class liner is 121 kWh per 100 pkm – more than twice that of the jumbo jet. Source

Sulfur in fuel for shipping

At present ships use bunker C fuel. It is the left over fraction from oil refining, it is like bitumen, and at normal temperature it is solid enough to walk on. It needs to be heated to make it flow into the engine.

It contains 3.5% sulfur and other impurities, so is quite cheap. Reducing the sulfur to 0.5% doubles the cost, and the shipping industry is naturally resisting.

The world's shipping emits 250 times more SO₂ and SO₃ (SO_x) than all the worlds cars. The largest 15 ships give off the same SO_x as all the worlds cars. 

The new limits set for the Baltic sea and English Channel are 1.5% S and 0.1% S for inland waterways.

Normal diesel fuel for land based engines is 10 mg/KG, 10 ppm or 0.001% S.

NO_x data from ships can be found at http://coast.cms.udel.edu/sea/nitrogen.html

Particles emitted in ship exhaust

The small particles (soot) emitted from the ships' engines causes 60,000 deaths each year. If we lose 10 people in a shipwreck then it is world news. These 60,000 slow painful deaths are rarely mentioned.

Mortality from Ship Emissions: A Global Assessment

Epidemiological studies consistently link ambient concentrations of particulate matter (PM) to negative health impacts, including asthma, heart attacks, hospital admissions, and premature mortality. We model ambient PM concentrations from oceangoing ships using two geospatial emissions inventories and two global aerosol models. We estimate global and regional mortalities by applying ambient PM increases due to ships to cardiopulmonary and lung cancer concentration-risk functions and population models. Our results indicate that shipping-related PM emissions are responsible for approximately 60,000 cardiopulmonary and lung cancer deaths annually, with most deaths occurring near coastlines in Europe, East Asia, and South Asia. Under current regulation and with the expected growth in shipping activity, we estimate that annual mortalities could increase by 40% by 2012.  Ref...

 

James J. Corbett*†, James J. Winebrake‡, Erin H. Green‡, Prasad Kasibhatla, Veronika Eyring and Axel Lauer

College of Marine and Earth Studies, University of Delaware,

This chart is based on a data set of particle number coarser than 2.5 nm (N), black carbon (BC), gaseous pollutants (NOx, SO2, CO and O3), PM2.5 and PM10 measured from 2008 to 2010 in the ambient air of Santa Cruz de Tenerife City, where a previous study found an association between hospitalizations due to heart failure and exposure to UFPs in the ambient air. Source: Science Direct

Deaths from small particles emitted by oil powered ships.  60,000 deaths each year from ship emissions.

How do we know pollution is from ships?

Scientists measuring the emissions use concentration of Vanadium V and nickel Ni. These are present in heavy fuel  oil used in ships, but not in normal diesel used by land vehicles.

SO_x is shorthand for SO₂ and SO₃

NO_x is shorthand for N₂O₃, NO, and NO₂