Reducing energy consumption and the heavy reliance on oil for propulsion is a
key challenge for sustainable maritime transportation. Marine bunker fuels are very
polluting and have a high carbon intensity. In addition, the affordability of maritime
transport service could be jeopardized by high and volatile oil prices. A future of low
oil prices, however, could undermine the needed transition sustainability.
10.4.2 Air Pollution with a Focus on the 2020 Sulfur Cap
Sulfur dioxide is not considered a greenhouse gas, and it has been argued that SO 2
has a cooling effect. The long-recognized harmful effects of sulfuric acid deposition
to land-based ecosystems have led to strict regulation on land-based sources of SO 2
(power stations and vehicle emissions) with concomitant reductions of the sulfur
burden over North America and Europe. Fossil fuel combustion from power plants is
the largest source of SO 2 emissions (73%). Industrial facilities are the second largest
source (20%) followed by smaller sources that include burning of high-sulfurcontaining fuels by locomotives, non-road equipment, and large ships (EPA
2013). Emissions from shipping have been poorly regulated despite evidence of
enhanced acidification in coastal regions. As a result shipping is responsible for a
large proportion of man-made SO 2 emissions (Endres et al. 2018). In the year 2000,
SO 2 emissions from shipping were three times greater than that from all traffic and
aviation combined (Eyring et al. 2005). On some calculations a single container
carrier emits as much SOx as 50 million of diesel cars (International Gas Union
2017). Shipping is thus by far one of the world’s top sources of SOx as well as a
major source of NOx and GHG emissions. NOx and SOx emissions from international ships account for about 13% and 12%, respectively, over the 2007–2012
period (IMO 2014). One large container ship visiting a port is estimated to produce
the equivalent amount of NOx as that of 12,500 cars (McKinnon 2016). These
emissions are closely associated with heavy bunker fuels. Ships have been an
important cause of premature deaths and respiratory symptoms as winds carry
marine emission inland (EPA 2016).
The International Maritime Organization (IMO) regulates air pollution from
shipping through the International Convention for the Prevention of Pollution
from Ships (1973) as modified by the Protocol 1978 (MARPOL). Annex VI of
MARPOL specifically regulates airborne emissions from ships and entered into
force in 2005. Emission control areas (ECAs) in Europe and the Americas enforce
stricter limits on SOx emissions. New control areas are being established in China.
Shipping will be required to meet the global sulfur cap of 0.5% by 2020. Stricter
NOx ECA limits came into effect in 2016 in North America, and Northern Europe
will apply NOx ECA to ships built from 2021 (Benamara et al. 2019).
The new IMO regulations due to take effect in January 2020 aim to drastically
lower the sulfur cap for air emission from ships. The three main options available to
shippers on current technology are to run on liquefied natural gas (LNG), to use
HSFO and process air emissions through an exhaust gas cleaning system (EGCS)
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A. Papandreou et al.
key challenge for sustainable maritime transportation. Marine bunker fuels are very
polluting and have a high carbon intensity. In addition, the affordability of maritime
transport service could be jeopardized by high and volatile oil prices. A future of low
oil prices, however, could undermine the needed transition sustainability.
10.4.2 Air Pollution with a Focus on the 2020 Sulfur Cap
Sulfur dioxide is not considered a greenhouse gas, and it has been argued that SO 2
has a cooling effect. The long-recognized harmful effects of sulfuric acid deposition
to land-based ecosystems have led to strict regulation on land-based sources of SO 2
(power stations and vehicle emissions) with concomitant reductions of the sulfur
burden over North America and Europe. Fossil fuel combustion from power plants is
the largest source of SO 2 emissions (73%). Industrial facilities are the second largest
source (20%) followed by smaller sources that include burning of high-sulfurcontaining fuels by locomotives, non-road equipment, and large ships (EPA
2013). Emissions from shipping have been poorly regulated despite evidence of
enhanced acidification in coastal regions. As a result shipping is responsible for a
large proportion of man-made SO 2 emissions (Endres et al. 2018). In the year 2000,
SO 2 emissions from shipping were three times greater than that from all traffic and
aviation combined (Eyring et al. 2005). On some calculations a single container
carrier emits as much SOx as 50 million of diesel cars (International Gas Union
2017). Shipping is thus by far one of the world’s top sources of SOx as well as a
major source of NOx and GHG emissions. NOx and SOx emissions from international ships account for about 13% and 12%, respectively, over the 2007–2012
period (IMO 2014). One large container ship visiting a port is estimated to produce
the equivalent amount of NOx as that of 12,500 cars (McKinnon 2016). These
emissions are closely associated with heavy bunker fuels. Ships have been an
important cause of premature deaths and respiratory symptoms as winds carry
marine emission inland (EPA 2016).
The International Maritime Organization (IMO) regulates air pollution from
shipping through the International Convention for the Prevention of Pollution
from Ships (1973) as modified by the Protocol 1978 (MARPOL). Annex VI of
MARPOL specifically regulates airborne emissions from ships and entered into
force in 2005. Emission control areas (ECAs) in Europe and the Americas enforce
stricter limits on SOx emissions. New control areas are being established in China.
Shipping will be required to meet the global sulfur cap of 0.5% by 2020. Stricter
NOx ECA limits came into effect in 2016 in North America, and Northern Europe
will apply NOx ECA to ships built from 2021 (Benamara et al. 2019).
The new IMO regulations due to take effect in January 2020 aim to drastically
lower the sulfur cap for air emission from ships. The three main options available to
shippers on current technology are to run on liquefied natural gas (LNG), to use
HSFO and process air emissions through an exhaust gas cleaning system (EGCS)
158
A. Papandreou et al.