Emission from international sea transportation and environmental impact

Abstract

Emission generated by the international merchant fleet has been suggested to represent a significant contribution to the global anthropogenic emissions. To analyze the impacts of these emissions, we present detailed model studies of the changes in atmospheric composition of pollutants and greenhouse compounds due to emissions from cargo and passenger ships in international trade. Global emission inventories of NOx, SO2, CO, CO2, and volatile organic compounds (VOC) are developed by a bottom‐up approach combining ship‐type specific engine emission modeling, oil cargo VOC vapor modeling, alternative global distribution methods, and ship operation data. Calculated bunker fuel consumption is found in agreement with international sales statistics. The Automated Mutual‐assistance Vessel Rescue system (AMVER) data set is found to best reflect the distributions of cargo ships in international trade. A method based on the relative reporting frequency weighted by the ship size for each vessel type is recommended. We have exploited this modeled ship emissions inventory to estimate perturbations of the global distribution of ozone, methane, sulfate, and nitrogen compounds using a global 3‐D chemical transport model with interactive ozone and sulfate chemistry. Ozone perturbations are highly nonlinear, being most efficient in regions of low background pollution. Different data sets (e.g., AMVER, The Comprehensive Ocean‐Atmosphere Data Set (COADS)) lead to highly different regional perturbations. A maximum ozone perturbation of approximately 12 ppbv is obtained in the North Atlantic and in the North Pacific during summer months. Global average sulfate loading increases with 2.9%, while the increase is significantly larger over parts of western Europe (up to 8%). In contrast to the AMVER data, the COADS data give particularly large enhancements over the North Atlantic. Ship emissions reduce methane lifetime by approximately 5%. CO2 and O3 give positive radiative forcing (RF), and CH4 and sulfate give negative forcing. The total RF is small (0.01–0.02 W/m2) and connected with large uncertainties. Increase in acidification is 3–10% in certain coastal areas. The approach presented here is clearly useful for characterizing the present impact of ship emission and will be valuable for assessing the potential effect of various emission‐control options.

Field test of available methods to measure remotely SO<sub>x</sub> and NO<sub>x</sub> emissions from ships

“…According to Endresen et al (2007) If on one side shipping plays a fundamental role in world economy moving 80-90 % of world trade by volume (European Commission and Entec UK Limited, 2005), on the other side the negative effects related to its atmospheric emissions have been neglected for a long time. The related combustion process releases into the atmosphere several products and by-products (Lloyd's Register of Shipping, 1995): carbon dioxide (CO 2 ), nitrogen oxides (NO x ), sulphur dioxide (SO 2 ), particulate matter (PM), volatile organic compounds (VOCs), black/elemental carbon (BC/EC), and organic carbon (OC).…”

“…According to different studies (e.g. Endresen et al, 2003;Eyring et al, 2005), 70 % or more of emissions by international shipping occur within 400 km off land and they can consequently be transported hundreds of kilometres inland. This pathway is especially relevant for deposition of sulphur and nitrogen compounds, which cause acidification/eutrophication of natural ecosystems and freshwater bodies and threaten biodiversity through excessive nitrogen input (Isakson et al, 2001;Galloway et al, 2003).…”

Assessing the effect of marine isoprene and ship emissions on ozone, using modelling and measurements from the South Atlantic Ocean

“…Ships do, however, also emit hydrocarbons into the atmosphere albeit in small amounts relative to NO x , SO 2 , CO and CO 2 . [31,33,34] Any significant emission of anthropogenic reactive hydrocarbons in the ships exhaust would moderate the relative effect of the biogenic VOC source discussed above, but still provide photochemical fuel for ozone production. Cruising vessels emit NO x and VOC in the ratio 24-36 : 1 by weight.…”

Modelling the atmospheric transport and deposition of sulphur and nitrogen over the United Kingdom and assessment of the influence of SO2 emissions from international shipping

“…However the benefit in these emissions reductions is partially offset by the increasing contribution of emissions from international shipping. Estimations of emissions of SO 2 and NO x from international shipping suggest annual increases of 2.5% (Endresen et al, 2003) caused by increasing traffic and lack of emissions controls. The sulphur content of diesel oil for road traffic was recently lowered by European Community legislation from 350 ppm to 50 ppm.…”

“…However in European waters, the average sulphur content of marine heavy fuel oil was recently estimated at 2.7% (27,000 ppm) (EEB, 2004). Recent inventories estimate ship emissions of SO 2 to globally contribute between 3.2 Tg [S]/yr (Endresen et al, 2003) to 4.7 Tg [S]/yr (Corbett and Köhler, 2003).…”