Environmental impacts of the expected increase in sea transportation, with a particular focus on oil and gas scenarios for Norway and northwest Russia

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1 JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 112,, doi: /2005jd006927, 2007 Environmental impacts of the expected increase in sea transportation, with a particular focus on oil and gas scenarios for Norway and northwest Russia Stig B. Dalsøren, 1 Øyvind Endresen, 2 Ivar S. A. Isaksen, 1 Gjermund Gravir, 2 and Eirik Sørgård 3 Received 30 November 2005; revised 23 August 2006; accepted 12 September 2006; published 30 January [1] We have complemented existing global sea transportation emission inventories with new regional emission data sets and scenarios for ship traffic and coastal activity in Emission inventories for 2000 and 2015 are used in a global Chemical Transport Model (CTM) to quantify environmental atmospheric impacts with particular focus on the Arctic region. Although we assume that ship emissions continue to increase from 2000 to 2015, reductions are assumed for some chemical components and regions because of implementation of new regulations. Current ship traffic (2000) is estimated to contribute significantly to coastal pollution. Norwegian coastal ship traffic is responsible for more than 1/3 and 1/6 of the Norwegian NO x and SO 2 emissions, respectively. For these short-lived components the impact of Norwegian coastal emissions is regionally important. For most components the international ship transportation outside coastal waters dominates the effects. Ship emissions increase wet deposition in Scandinavia with 30 50% for nitrate and 10 25% for sulfate. In general, coastal regions with prevailing onshore winds show substantial increases in deposition of acid components. Maximum surface increase in ozone is in excess of 10 ppbv. Column ozone increases are also significant. Assuming no changes in nonshipping emissions, scenarios for shipping activities in 2015 lead to more than 20% increase in NO 2 from 2000 to 2015 in some coastal areas. Ozone increases are in general small. Wet deposition of acidic species increases up to 10% in areas where current critical loads are exceeded. Regulations limiting the sulfur content in the fuel in the North Sea and English Channel will be an efficient measure to reduce sulfate deposition in nearby coastal regions. The expected oil and gas transport by ships from Norway and northwest Russia, sea transport along the Northern Sea Route and new Norwegian coastal gas power plants will have a significant regional effect by increases of acid deposition in north Scandinavia and the Kola Peninsula. Augmented levels of particles in the Arctic are calculated, and thus the contribution from ship traffic to phenomena like Arctic haze could be increasing. Citation: Dalsøren, S. B., Ø. Endresen, I. S. A. Isaksen, G. Gravir, and E. Sørgård (2007), Environmental impacts of the expected increase in sea transportation, with a particular focus on oil and gas scenarios for Norway and northwest Russia, J. Geophys. Res., 112,, doi: /2005jd Introduction [2] Several studies have modeled impacts of ship emissions on various chemical components, both on a regional [Jonson et al., 2000; Davis et al., 2001; Conservation of Clean Air and Water in Europe, 1994] and global basis [Endresen et al., 2003; Lawrence and Crutzen, 1999; Capaldo et al., 1999; Kasibhatla et al., 2000; von Glasow et al., 2003; Song et al., 2003]. The interaction between 1 Department of Geosciences, University of Oslo, Oslo, Norway. 2 Det Norske Veritas, Høvik, Norway. 3 National Centre for Innovation and Entrepreneurship, Bodø, Norway. Copyright 2007 by the American Geophysical Union /07/2005JD chemical active gases is highly nonlinear and atmospheric changes might deviate substantially from the changes in emissions. This study aims to quantify the significance of atmospheric ship emissions on pollutants, greenhouse gasses and acidic deposition in the Arctic area for year 2000 and 2015 calculated by a global chemical transport model (CTM). A comparison is also made with our earlier global ship study [Endresen et al., 2003]. In this paper we apply the model in a higher spatial resolution with updated year 2000 emission data sets for nonship sources. Other improvements are introduction of Norwegian coastal emissions, inclusion of black and organic carbonaceous aerosols and sulfur chemistry run simultaneously with the rest of the chemistry scheme. [3] The ecosystem in the Arctic and in the Barents Sea region is vulnerable to different environmental threats, such 1of30

2 Table 1. Overview of Emission Data Sets Used in This Study Year 2000 Year 2015 Emission Sources Abbreviation Coverage Magnitude/Activity Section Change Section All sources (except ships) GLOBAL global fossil fuel, industry, biofuel, land use, natural International shipping fleet COADS global cover mainly the oceangoing world fleet 2.1 2%/year 2.5 Norwegian coastal shipping NCS Norwegian coast %/year 2.5 Northern Sea Route transit NSR Russia-Asia a 0 ::: 200 ships 2.7 Oil and gas transport Norway OILGAS Barents-Europe/US 0 ::: 1,500 ships 2.6 and northwest Russia Power supply activity Norway POWER Norwegian coast 0 ::: two gas power plants 2.8 a Arctic region. as increasing amounts of chemical active air pollutants, radioactivity, contamination and remobilization of persistent organic pollutants and heavy metals [Arctic Monitoring and Assessment Programme, 2002; O Brien et al., 2004]. The Arctic is now experiencing some of the most rapid climate changes on earth. On average, temperature has risen at twice the rate of the rest of the world [Hassol et al., 2004]. Melting glaciers, reductions in extent and thickness of sea ice, thawing permafrost and rising sea level are indications of a recent warming in the region. An acceleration of these climate trends is projected to occur in the coming century [Hassol, 2004]. Several air pollutants and their precursors also have a direct or indirect effect on climate change. Sulfate and other aerosols might contribute to Arctic haze, a phenomenon first reported by weather reconnaissance missions in the fifties [Shaw, 1995]. Arctic haze and higher altitude haze often contain increased amounts of pollutants and aerosols transported from anthropogenic and natural sources on the continents and affects visibility and regional climate [Koch and Hansen, 2005; Rinke et al., 2004; Shaw, 1995]. Ozone is both a harmful pollutant at high concentrations [Mauzerall and Wang, 2001; World Health Organization, 2001] and an important climate gas [Ramaswamy et al., 2001] with sufficient lifetime for transport away from the source region of its precursors. In order to asses the overall regional impact an integrated approach is needed [O Brien et al., 2004] to both evaluate the effect on climate and pollution taking into account the most important components emitted from increasing activity. Climate change in the Arctic will in turn mediate the transport, uptake and remobilization of contaminants in the area. The Arctic also provides important natural resources to the rest of the world and climate change here is connected to global climate change through several couplings both in atmospheric circulation and the thermohaline circulation in the ocean. [4] Scenarios for future global shipping activities indicate significant growth that will be followed by increased energy consumption and emissions [Eyring et al., 2005a]. The offshore, petroleum and shipping activities at higher latitudes have increased considerably over the last years, and a significant further increase is expected [Frantzen and Bambulyak, 2003, 2005; Brunstad et al., 2004]. More than 1500 oil tankers may in 2015 export oil via the Barents Sea and the northeast Atlantic to Europe and the US. The seaborne cargo transport in these waters has previously been very limited [Protection of the Arctic Marine Environment (PAME), 2000], and the reported ship emissions low [PAME, 2000; Corbett et al., 1999; Endresen et al., 2003]. Although the use of the Northern Sea Route (NSR) for international transit shipping operations to Asia today is limited, this route should not be underestimated if the ice thickness and coverage decrease due to regional warming [Hassol, 2004]. Several gas power plants are also planned along the Norwegian coast. On the basis of these projections we have developed new regional emission data sets to quantify environmental impacts of these activities in We make an assumption of no changes from 2000 to 2015 in the existing adopted nonship inventories. [5] In this study we first present a description of the developed and applied emissions inventories for year 2000 and 2015 (section 2). At the end of the emission section (section 2.9), there is a general discussion on emission increases toward 2015 of the long-lived greenhouse gases CO 2,CH 4 and N 2 O not included in the CTM calculations. In section 3 we describe the CTM model and the setup of the CTM simulations for the calculations of the atmospheric environmental impacts. Section 4 is devoted to the results of the CTM simulations. In section 5 our major findings are summarized and some results are discussed in a broad perspective. 2. Emission Inventories Year 2000 and 2015 [6] The first part of this section gives a description of the emission inventories we have developed and used for our calculations of environmental impacts in We focus on the new data set developed for Norwegian coastal shipping. The existing inventories applied in this study are described briefly. We then discuss adoption of scenarios for year 2015 made with existing year 2000 emission data sets as basis. We also present new inventories for expected future regional emissions of importance for the CTM studies. This study combines a well of emission data to best represent the current situation (year 2000) and the future (year 2015). Table 1 gives an overview of the data sets used. A further description of each data set and their content is given in the proceeding sections Global International Ship Emissions for 2000 [7] In this study we use the year 2000 international ship emissions reported by Endresen et al. [2003], and the year 1996 Comprehensive Ocean-Atmosphere Data Set (COADS) traffic density map [Worley, 2001]. COADS from the National Centre for Atmospheric Research (NCAR) and the National Oceanic and Atmosphere Administration (NOAA), is the most extensive collection of global surface 2of30

3 Figure 1. Fairways and traffic densities for north of Norway, COADS traffic density and AIS tracks [NCA, 2005]. marine data available. The data set has been used in several studies. For instance, COADS was used by Corbett et al. [1999] to distribute global inventories of nitrogen and sulfur emissions from international maritime transport. Endresen et al. [2003] analyzed the impacts of ship emissions using COADS, Purplefinder and Automated Mutual-assistance Vessel Rescue System (AMVER) traffic density maps, and presented detailed model studies of the effects on atmospheric composition of pollutants and greenhouse compounds. For this study, we used the COADS standard version for 1996 [Endresen et al., 2003, Figure 1] statistically summarized on a monthly basis with a 1 1 spatial resolution [Worley, 2001]. COADS includes mainly cargo ships, but also noncargo vessels [Endresen et al., 2003]. We assume that this data set represents cargo ships operating internationally and regionally. However, we do not expect COADS to cover national coastal trade. [8] For VOC evaporation from large crude oil carriers during loading, transport and unloading we use the emission inventory reported by Endresen et al. [2003], which is based on the main international oil transportation routes. [9] There is still a debate regarding the actual regional [Beirle et al., 2004] and global total levels of emissions [Endresen et al., 2003, 2004; Corbett and Köhler, 2003; Corbett, 2003; Eyring et al., 2005b]. Added to this is the uncertainty in the applied traffic distributions. The uncertainties connected to COADS were briefly discussed by Endresen et al. [2003], with recommendation to use AMVER for global studies. However, as outlined by Endresen et al. [2003] and Corbett and Köhler [2003] the AMVER data may be biased toward the medium and large cargo ships, while COADS also includes smaller ships and noncargo ships. Thus we assume that COADS best reflect the different vessels sizes and types. The largest uncertainty by using the COADS data is their limited representativeness since they only cover about 10% of the oceangoing world fleet. 1.2%, 1.4%, and 1.6% of the total observations in COADS are at latitudes higher than 69, 68 and 67 north, respectively. PAME [2000], reports that the Arctic fleet consume some 1% of the total fuel used by ships in the world fleet. This implies that the COADS distribution seems to represent well the emissions in the Arctic which is our main focus region Emissions From Norwegian Coastal Shipping in 2000 [10] Norway has substantial coastal ship traffic not accounted for in existing inventories that only handle international ship emissions. Shipping along the Norwegian coast also makes a significant contribution to Norway s total emissions for several components. Statistics for Norwegian emissions [Statistics Norway, 2004] show that shipping in 2003 is responsible for about 40% of the national NO x emissions, 17% of SO 2,9%ofCO 2 and roughly 1% of CO, NMVOCs and PM. [11] The Norwegian merchant fleet (registered in Norway) larger than 25 gross tonnage (GT) in 1999 counted some 4,430 vessels [Statistic Norway, 2000]. About of30

4 Table 2. Total Year 2000 Emissions From Norwegian Coastal Shipping Used in This Study a Component Total NOx b,c 83,556.5 CO 2 3,781,479 b SO 2 17,200 CO b 6,501.4 NMVOC b 1,633.4 d CH PM b 9,066.4 e N 2 O 94.6 a Emissions are in tons. b Emissions included in the CTM simulations, the effects of the long-lived greenhouse gases CH 4, CO 2 and N 2 O are evaluated in the general discussion. c Given as tons (NO 2 ). d Separation of individual NMVOC components as in the work by Endresen et al. [2003]. e For PM from ships the majority of particles are carbonaceous [Hobbs et al., 2000]. We assume that 80% is organic carbon, 4% black carbon [Sinha et al., 2003] and that 10% of the emitted carbonaceous particles are hydrophilic [Hobbs et al., 2000]. larger ships operate in foreign trade [Behrens et al., 2002], and the remaining operate mainly in Norwegian waters. Figure 1 shows the fairways for Norwegian coastal traffic, plotted together with the COADS traffic distribution, and AIS (Automatic identification systems) tracks [Norwegian Coastal Administration (NCA), 2005]. AIS is primarily an anticollision system, and is designed to be capable of automatically providing information about the ship to other ships and to coastal authorities. The International Maritime Organisation (IMO) requires AIS to be fitted aboard all international ships of certain size. We expect that in the future local and regional ship emission inventories will be based on AIS statistics. [12] Statistics Norway [2001] reports that the fuel consumption by ships in national sea traffic is about 1000 Kt fuel in 1998, excluding fishing vessels. The fuel usage by foreign ships in national waters (to/from Norwegian ports and between Norwegian ports) is in 1996 estimated to 263 Kt, on the basis of a detailed movement study, allocating emissions on the main Norwegian sea routes and ports [Statistics Norway, 1998]. We multiply the 1996 geographical distributed (Figure 1) foreign ships emission inventory with a factor of 5 to estimate total coastal ship inventory for year 2000 (not including fishing vessels). It is important to recognize that this is a rough estimate that is made to include contributions from national shipping. For SO 2 emissions this method is not applicable as there are large differences in sulfur fuel content between foreign and national ships (in Norwegian waters). For foreign ships Statistics Norway [1998] assume that ships with engines less than 2000 kw use 0.5% sulfur and the rest use heavy fuel with 2.7% sulfur content. The foreign going fleet is dominated by relatively large ships consuming mainly heavy fuel, and SO 2 emissions was estimated to 12.4 Kt/ year [Statistics Norway, 1998]. For the national fleet in 1998 (including the fishing fleet) only 121 Kt is heavy fuel and the resulting SO 2 emissions were estimated to 4.8 Kt/year [Statistics Norway, 2001]. On the basis of these estimates we assumed 17.2 Kt SO 2 emitted from foreign and national ships in coastal sea traffic in year 2000, not including fishing vessels. The total coastal ship emissions for all components in 2000 (from foreign and national ships in coastal sea traffic) are given in Table 2. [13] Foreign ships entering or leaving the Norwegian territorial area may be double-counted since these ships might also be registered by COADS. Approximately half of the foreign ships fuel consumption is related to international traffic to and from the Norwegian coast, whereas half of the foreign ships operate between Norwegian harbors [Statistics Norway, 2001]. We expect the possible mistake to be of little importance for our calculations of environmental impacts. It would for instance correspond to less than 1/10 of the emissions in Table 2 (a higher number for SO 2 because of the high sulphur content in the fuel of foreign ships) and an even much lower fraction if we compare with the regional emissions in COADS. All the Norwegian ships are assumed to operate in Norwegian coastal waters but some of them may go from harbors in Norway to international ports. This may add another potential bias to the data Figure 2. Oil shipment from northwest Russia during the first 7 months of 2002, 2003 and 2004 (Y. Årøy, Norwegian Defence, personal communication, s2004): (left) Number of oil tankers and (right) amount of oil transported. 4of30

5 Figure 3. Northern Sea Route, expected oil trades and main ports for the tanker transport in The defined sea routes are used when allocating 2015 emissions. as we might overestimate the emissions in coastal waters and underestimate the emissions in international water Global Data Sets for Emissions From Other Sources in 2000 and 2015 [14] In this study we used the emission inventory for the year 2000 available from the EU-funded project POET [Olivier et al., 2003]. This database contains emissions of NO x, CO and NMVOCs as well as methane concentration fields based on surface observations. For emissions of organic and black carbonaceous aerosols the inventories of Cooke et al. [1999] and Liousse et al. [1996] were used. The sulfur chemistry and the emissions of sulfur components are described by Berglen et al. [2004]. The lightning NO x emissions are based on Price et al. [1997a, 1997b] and Pickering et al. [1998] and set to 5 Tg (N). [15] For year 2015 we assume no changes in the emissions we adopted for year This is due to the fact that we wanted to focus solely on the effect of changes in shipping and offshore activity emissions. Table 3. Emission Factors for Gas Compounds Related to Oil and Gas Transport From Norway and Northwest Russia in 2015, Based on EMEP/CORINAIR [2002] Emission Factors for Engine Types, kg Emitted Gas Component per Ton Fuel, Slow Speed Carbon monoxide (CO) 7.4 Nonmethane volatile organic 2.4 compounds (NMVOC) Methane (CH 4 ) 0.05 Carbon dioxide [CO 2 ] 3170 Sulfur dioxide (SO 2 ) NON SECA: 2.7% sulfur content a 54 SECA: 1.5% sulfur content b 30 EU Port: 0.2% sulfur content c 4 Oxides of nitrogen (NO x ) d 74 Particulate matter (PM) e 7.6 a According to Endresen et al. [2005]. b According to Annex VI [IMO, 2002]. c According to directive 1999/32/EC [EU, 1999]. d 15% reduction taken into account. e Average estimate with the effect of fuel type taken into account. 5of30

6 Table 4. Expected Emissions From Oil Transport by Tankers From Northern Norway and Northwest Russia in 2015 a Component Sector NOx b,c CO 2 b SO 2 CO b NMVOC b CH 4 PM b N 2 O Norwegian 21, , , , d ,009.7 e 24.9 Russian 86, ,940, , , ,983.3 d ,038.8 e 99.4 Murmansk f 63,750.0 d 11,250.0 d Total 107, ,925, , , ,579.1 d 11, ,048.5 e a Emissions are in tons. b Emissions included in the CTM simulations, the effects of the long-lived greenhouse gases CH 4,CO 2 and N 2 O are evaluated in the general discussion. c Given as tons (NO 2 ). d Separation of individual VOC components as in the work by Endresen et al. [2003]. e For PM from ship the majority of particles are carbonaceous [Hobbs et al., 2000]. We assume that 80% is organic carbon, 4% black carbon [Sinha et al., 2003] and that 10% of the emitted carbonaceous particles are hydrophilic [Hobbs et al., 2000]. f Evaporation from handling of crude oil Fuel Consumption Trends for Ships Toward 2015 [16] The demand for seaborne trade follows the general economical growth and doubled during the period [United Nations Conference on Trade and Development (UNCTAD), 2003]. The average yearly economical growth rate for the period is reported to be 2.7% [UNCTAD, 2004], while the corresponding average yearly growth rate for seaborne trade is about 3% [Fearnleys, 2001]. The growth in energy consumption seems to follow the world seaborne trade after 1970 (Ø. Endresen et al., A historical reconstruction of ship energy consumption and CO2 emissions, submitted to Journal of Geophysical Research, 2006). The annual growth rate of world seaborne trade is expected to be in the range of % for the period [Skjølsvik et al., 2000]. On the basis of the data given above, we have assumed a 2% yearly increase in global world seaborne trade up to 2015, and similar growth in ship bunker fuel consumption. A corresponding growth in national fuel consumption is assumed from the Norwegian coastal traffic, in agreement with the general increase in national bunker sale reported by Statistics Norway [2001]. The export of goods in the world has increased by 5%, 6% and 13% respectively for 2002, 2003 and 2004 [UNCTAD, 2005]. For Southeast Asia the increase was 12%, 17% and 22%, and for China 25%, 35% and 33%. This implies in general more international traffic Table 5. Emissions From NSR Transit Ship Operations a Component Total NOx b,c 7,400 CO 2 317,000 b SO 2 5,400 CO b NMVOC b d CH d PM b e N 2 O 7.97 a Emissions are in tons. b Emissions included in the CTM simulations, the effects of the long-lived greenhouse gases CH 4, CO 2 and N 2 O are evaluated in the general discussion. c Given as tons (NO 2 ). d Separation of individual VOC components as in the work by Endresen et al. [2003]. e For PM from ship the majority of particles are carbonaceous [Hobbs et al., 2000]. We assume that 80% is organic carbon, 4% black carbon [Sinha et al., 2003] and that 10% of the emitted carbonaceous particles are hydrophilic [Hobbs et al., 2000]. and emissions world wide, and significantly more traffic in Southeast Asia and China. Our assumption about a uniform global 2% yearly increase in fuel consumption may therefore be conservative. Studies focusing on future effects of ship emissions in Southeast Asia and China should probably include several sensitivity calculations with different emission assumptions because of uncertainties about the rapid economical development in the region. [17] Presently, alternative propulsion and fuel types receive much attention as a possible mean to reduce atmospheric emissions from power producing machinery. Possible future solutions for ships are discussed by Eyring et al. [2005a]. Though new technologies are promising options, they will likely have a small influence over the next 20 years given the remaining development needs, the implementation period requiring the build of a new fuel supply infrastructure and the long life time for ships. However, the emissions of some components may be reduced as a consequence of stricter regulations. This is discussed in detail in section Emissions From Global International and Norwegian Coastal Shipping in 2015 [18] The fuel based emission factors used in the calculations are based on European Monitoring and Evaluation Program/Core Inventory of Air Emissions (EMEP/ CORINAIR) [2002]. Technological development and new legislation may result in changed emission factors in the future which have an impact on the emissions. [19] IMO s MARPOL (International Maritime Organization s Marine Pollution convention) Annex VI defines limits on sulfur oxide and nitrogen oxide emissions from ship exhausts and prohibits deliberate emissions of ozone de- Table 6. Yearly Emissions From Gas Power Plants and Activities at Kårstø and Snøhvit in 2015 a Location and Source NO x b CO 2 c NMVOC CH 4 Snøhvit LNG Energy facility , Processor facility, tankers, etc , Kårstø Energy facility 150 1,565,000 Processor facility, tankers, etc ,000 2,870 1,225 a Emissions are in tons. Based on several reports from SFT and MD [MD, 2005; SFT, 2002, 2004, 2005]. b Given as tons (NO 2 ). c Without CO 2 handling. 6of30

7 Table 7. Overview of Simulations Performed in This Study Model Simulation Simulation Name Emissions Database Included (See Table 1) Section No ship emissions NOSHIP GLOBAL 4.1 NOSHIP + international ship emissions INTSHIP GLOBAL + COADS 4.2 NOSHIP + international + Norwegian ALLSHIP GLOBAL + COADS + NCS 4.1 and 4.2 coastal shipping NOSHIP + international Norwegian ALLSHIP2015 GLOBAL + COADS NCS coastal shipping 2015 ALLSHIP increased coastal and transport activity Norway and Russia SCENARIO2015 GLOBAL + COADS NCS OILGAS + NSR + POWER 4.3 and 4.4 pleting substances [International Maritime Organization (IMO), 2002]. Annex VI entered into force 19 May Annex VI includes a global cap of 4.5% on the sulfur content (by weight) of fuel oil. However, only 0.02% of all samples analyzed in 1996 showed sulfur contents above the Annex VI limit [Cullen, 1997] and in 2002 the average sulfur content level was 2.7% for heavy fuel [Endresen et al., 2005]. Thus the Annex VI regulation does not imply any general improvement in existing sulfur emission levels. IMO have however within Annex VI adopted the Baltic Sea and the North Sea as special SO x Emission Control Areas (SECA) with more stringent controls on sulfur emissions from ships. In these areas the sulfur content of fuel oil will be limited to 1.5%. The main existing EU regulation for oceangoing vessels is directive 1999/32/EC [European Union (EU), 1999], Directive 2005/33/EC, amends Directive 1999/32/EC. Under this Directive, a 1.5% sulfur limit will apply from 11 August 2006 for all passenger vessels on regular services to or from EU ports, and for all ships in the Baltic Sea SECA. This is three months later than the May 19, 2006 enforcement date for the Baltic Sea under the IMO Convention. For the second SECA, the North Sea and English Channel, the EU Directive sets an earlier date than the IMO, 11 August 2007 compared to November Directive 2005/33/EC also sets the sulfur limit to 0.1% in fuel consumed by ships at berth in EU ports, and all inland vessels from Environmental Protection Agency (EPA) [2003] has proposed to limit the sulfur content in fuels for nonroad diesel engines to 0.05% by June The proposal includes a 15 ppm (0.0015%) cap by 2010 for nonroad distillate fuel. Although the primary proposal does not include locomotive and marine distillate fuels, such inclusions are under consideration. [20] Annex VI of MARPOL sets limits for emission factors of NO x. The regulation states that engines installed on ships constructed on or after 1 January 2000 or engines which undergo a major conversion on or after 1 January 2000 should meet the defined requirements. Figure 4. stations. Comparison of modeled ozone and NO 2 with surface observations at coastal and marine 7of30

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11 Figure 5. Ozone change at the surface due to year 2000 ship emissions for the months (top left) January, (top right) April, (bottom left) July and (bottom right) October. [21] Annex VI sets no limits for the reduction of VOC compounds, but gives the individual Party opportunities for design of ports and thermals in which VOC emissions are regulated. Endresen et al. [2003] estimated a loss of 0.1% during loading of crude oil. Because of the future technology improvements we assume a factor of loss of 0.05% in 2015 during an expected loading of 150 Mt oil (section 2.6) in the Murmansk region and no loss during transport and unloading of this oil. [22] Carbon dioxide (CO 2 ) emissions are not covered by Annex VI, but IMO s Marine Environmental Protection Committee (MEPC) considered a voluntary environmental indexing scheme to be the most appropriate mechanism at this stage [EU, 2002]. The 52nd MEPC session in October 2004 made progress on developing draft Guidelines on the CO 2 Indexing Scheme. Furthermore, PM, CO, VOC exhaust emissions are not covered by Annex VI, but EU considers reduction strategies [EU, 2002]. We have assumed no change in emissions factors for compounds not covered by Annex VI or existing EU regulations. [23] A yearly growth rate of 2% of the year 2000 inventory reported by Endresen et al. [2003] is assumed. For NO x and SO 2 there are, as discussed, specific regulations expected. Assuming emission limits are phased in as planned, EPA [1999] estimate the expected NO x reductions in US waters to 8% in 2015 and 14% in The global reduction of 30% as set out through MEPC in the early 1990s may therefore be too optimistic. We have assumed that a 15% global reduction of NO x in 2015 should be feasible as a result of the MARPOL Annex VI. For NO x emissions our assumed increase in bunker fuel consumption is therefore partially compensated by a global uniform 15% reduction due to regulations and related technology improvement. We are also conservative in our estimates for reductions of SO 2 emissions. We have assumed that the average level of 2.7% sulfur in heavy fuel still remains in all regions except the North Sea and the English Channel where a content of 1.5% is used because of regulations. The emissions are distributed on the same geographical map (COADS) as the year 2000 emissions (section 2.1), e.g., we do not assume any changes in traffic pattern. [24] As for the emissions from the international fleet we assume an expected increase in Norwegian national bunker fuel consumption of 2% per year and the same constrains on the NO x emissions as for the global fleet. The emissions are 11 of 30

12 Figure 6. NO 2 change at the surface due to year 2000 ship emissions for the months (top left) January, (top right) April, (bottom left) July and (bottom right) October. allocated on the on the traffic density map for the year 2000 Norwegian coastal ship emissions (section 2.2) Emissions From Oil and Gas Transport From Norway and Northwest Russia in 2015 [25] The Russian oil export is the second largest in the world, and had a yearly increase of about 10% over the last years (EIA, 2004 Country Analysis Briefs, doe.gov/emeu/cabs/russia.html). 1/3 of the total Russian oil production is planned to be exported via the Barents Sea by tankers [Dragsund and Johannessen, 2003]. The oil transportation along the Norwegian coastline from the northwest of Russia has increased considerably the last years (Figure 2), and a significant further increase is expected. The planned export via the Barents Sea is reported to be Mt oil in 2015, taken into account the planned western Siberia- Murmansk oil pipeline [Frantzen and Bambulyak, 2003, 2005; Brunstad et al., 2004; Dragsund and Johannessen, 2003]. This will require between yearly cargo voyages with tankers from northwest Russia to customers in western Europe and North America, and the same number of ballast voyages. Export of oil and gas is also expected to increase from the Norwegian sector. A forecast scenario indicates some 400 tank vessels a year by 2015, of which 85 gas tankers are from the Snøhvit field (in northern Norway) which will come into production in 2007 [Dragsund and Johannessen, 2003]. [26] This study assumes that 150 Mt oil is transported from northwest Russia in 2015, corresponding to a bunker fuel consumption of 1.24 Mt. It is assumed that 50% of the oil is transported to North America, and 50% to European customers. The oil shipment is assumed to be made with an average vessel size of 150,000 Dwt (dead weight tonnage), on the trade routes specified in Figure 3. PAME [2000] reports some 1.7 Mt fuel consumed by the whole Arctic fleet in The expected fuel consumption of 1.24 Mt/ year illustrates that emissions from the increased oil transport will significantly increase emissions along the main sea tanker routes. The number of days in open sea are calculated in GIS (Geographical Information System), assuming an average operation speed of 14 knots. The emission factors are given in Table 3 and exhaust gas emissions are estimated as outlined by Endresen et al. [2003]. All vessels are assumed to have VOC recovery units installed. [27] A GIS-model similar to the model presented by Endresen et al. [2003] has been developed to quantify ship emissions from the oil transport from Russia to the continent and the US. The model is based on separate calcu- 12 of 30

13 Figure 7. Ozone column change due to year 2000 ship emissions for the months (top left) January, (top right) April, (bottom left) July and (bottom right) October. lations of emissions in loading ports, on trade and at unloading ports, according to the number of voyages per year for a specified sea route. The number of voyages on each route is calculated on the basis of vessel sizes and on the oil amounts transported. It is assumed that after unloading of cargo, the vessels return on the same trade routes. The geographical locations for the emissions are modeled by defining polygons (port areas and ship lanes). The lane width of the trade routes is assumed to be 50 km, in accordance with observed patterns for ship traffic (Y. Å. Berggrav, personal communication, 2004). The emissions within each polygon are then mapped to a 1 1 grid. Table 4 and Figure 3 summarize the emissions related to the oil transport from northwest Russia. The increasing tanker transport connected to the Norwegian sector is included (Table 4) and distributed on the existing grid for Russian oil transport assuming a similar traffic pattern to Europe and the U.S. [28] The large range in projected yearly oil export ( Mt) is much related to the uncertainties in the political and economical development in Barents Russia toward 2015 [Brunstad et al., 2004]. We assume an upper estimate for Russian oil transport of 150 Mt/year but we have not included gas export from the Russian sector. The largest gas field discovered on the Barents shelf is the Shtokman field, one of the largest fields in the world. Its start date is not yet determined. There are major technical difficulties but plans have been made to land the gas east of Murmansk and export it either by pipeline or as liquefied natural gas (LNG) by ship as European and US gas demand are expected to grow in the future [Brunstad et al., 2004]. We assume that the export will start after our chosen 2015 scenario year and have therefore not included these possible emissions, which could become be significant Emissions From Northern Sea Route Transit Transport in 2015 [29] The Northern Sea Route (NSR) stretches from the Novaya Zemlya islands in the west to the Bering Strait in the east (see Figure 3). The transport volumes on NSR have been around Mt annually for the period The transit cargo flow was around Mt/year in the period and negligible from 1996 to 1999 [Fritjof Nansen Institute (FNI), 2000]. Several estimates have been forwarded by different sources in terms of overall transit cargo potential volumes. The development of shipping activity along the NSR is dependent on political 13 of 30

14 Figure 8. Nitrate wet deposition change due to year 2000 ship emissions for the months (top left) January, (top right) April, (bottom left) July and (bottom right) October. changes, energy demand, as well as climate change. On the basis of present cargo flows between Europe and the north Pacific Region, the eastbound NSR transit cargo potential is 2 3 Mt/year with annually voyages of vessels of about 50,000 dwt by a modest estimate, and 6 8 Mt/year corresponding to voyages by an upper estimate. The westbound NSR transit cargo potential is less than 1 Mt/year by a modest estimate, and 2 4 Mt/year in the upper scenario [FNI, 2000]. We assume that 200 cargo vessels will travel along the NSR via the Barents Sea. They typically use 25 days between Europe and the north Pacific Region and consume 20 tons of fuel per day. The water is shallow along the sea route [FNI, 2000] and the ship size is therefore assumed to be only 50,000 dwt. The emissions from these vessels are included along the route as shown in Figure 3 and the total emissions are given in Table 5. These emissions only represents some 6% of the CO 2 emissions reported by PAME [2000], of which some are emitted outside Arctic waters Emissions From New Norwegian Gas Power Plants in 2015 [30] In this study we include an evaluation of the environmental impacts of two coming gas power plants planned to be in production in The Snøhvit field 150 km north of Hammerfest in northern Norway will extract natural gas and transport it to the terminal at land where it is cooled down, transformed to LNG and further distributed by ships. At Kårstø in southwestern Norway a gas power plant is planned to be built in an area with existing terminals. [31] There are limitations to the emissions set by Norwegian authorities [MiljøvernDepartementet (MD), 2005; Statens ForurensingsTilsyn (SFT), 2002, 2004, 2005]. There are currently plans for five gas power plants in Norway and there could be more than two gas power plants in operation already in On the other hand, new technology and possible stricter emission legislation rules set by the authorities may reduce the expected emissions. CO 2 handling is high on the agenda and it has recently become more likely that new emissions will not be allowed without CO 2 handling. In the quantification of the impacts we have included emissions (see Table 6) from Snøhvit and Kårstø of components that are emitted in such amounts that they could affect the environment: CO 2 (approximately 5% of Norway s total emissions if no handling), NO x, NMVOC, and CH 4. The emissions of CO and sulfur 14 of 30

15 Figure 9. Sulfate wet deposition change due to year 2000 ship emissions for the months (top left) January, (top right) April, (bottom left) July and (bottom right) October. compounds from the gas activities are small and assumed insignificant Increase in Emissions of Long-Lived Greenhouse Gases Not Included in the CTM Calculations [32] The effect of international ship emissions on radiative forcing in 2000 was discussed by Endresen et al. [2003]. In this study we have reported emission estimates for CO 2,CH 4 and N 2 O. These components are not included in the CTM calculations, though the effect of OH changes on CH 4 is discussed in sections 4.1 and 4.3. In section 2.5 we assumed a 2% yearly emission increase of these components for the global international and Norwegian coastal fleet. The other 2015 scenario inventories (Norwegian coastal emissions, oil and gas transport, gas power plants, NSR) that we have introduced take place in northern areas and more or less along the Norwegian coast. We therefore compare CO 2,CH 4 and N 2 O emissions in these inventories with Norwegian total emissions in 2003 [Statistics Norway, 2004]. These sources represent approximately 30%, 5.4% and 1.5% of the Norwegian total emissions in 2003 for CO 2, CH 4 and N 2 O respectively. The amount of CH 4 emitted is very dependent on the capability of recovery systems to handle VOC evaporation from oil during loading in Murmansk (see section 2.5 and Table 4). The number for CO 2 will be up to 5% lower if CO 2 handling is demanded for the Norwegian gas power plants. 3. Model and Setup for Studies of Atmospheric Impact [33] The OsloCTM2 model [Berntsen and Isaksen, 1997; Sundet, 1997] is a three-dimensional global chemical transport model with several options for resolution, model domain (troposphere, stratosphere, both), meteorological data, type of chemistry and number of chemical components. In this study we used a tropospheric version with 19 vertical layers, T63 horizontal resolution (approximately ) and 67 species. The chemistry scheme uses the QSSA solver [Hesstvedt et al., 1978] to describe the gasphase chemical reactions of hydrogen, oxygen, nitrogen, carbon and sulfur components in the troposphere. The chemical scheme also includes two heterogeneous reactions, aqueous phase sulfur chemistry and a simplified description of black and organic carbon. The carbonaceous aerosols are divided into water-soluble (hydrophilic) and nonsoluble (hydrophobic). The lifetime is governed by dry and wet 15 of 30

16 Figure 10. Increase in surface NO 2 in July due to year 2000 Norwegian coastal traffic. deposition and a transfer of hydrophobic to hydrophilic aerosol [Cooke et al., 1999]. The meteorological data are based on the year 1996 forecast from the ECMWF IFS model [Sundet, 1997]. Advective transport is done using the Second-Order Moments method [Prather, 1986]. Parameters from the IFS model are used for parameterizations such as the boundary layer scheme, based on Holtslag et al. [1990], for convection, and for dry and wet deposition described in a section about deposition processes by [Berglen et al., 2004]. [34] In this study we have run the model in a high resolution (T63), however no subgrid plume model is included. We therefore discuss regional and global largescale patterns and do not focus on local ship tracks. Studies indicate that plume chemistry have to be better taken into account in the impact modeling [Chen et al., 2005; Song et al., 2003; von Glasow et al., 2003]. These studies suggest enhanced NO x destruction within the ship plumes. Although it is possible that we might overestimate the effect of ship emissions on the NO x and ozone budget, we calculate smaller NO x perturbations than in the Endresen et al. [2003] study which was done with coarser resolution and compared reasonably with the few observations available. [35] Ships emit aerosols directly and secondary aerosols also form in the ship plumes. Aerosols might impact levels of oxidants and photolysis rates [Tieetal., 2001]. These interactions are currently not included in the model. Grini et al. [2002, 2005] studied the model s capability to simulate aerosol distributions and the dependency on various transport mechanisms. The model does not include any feedback in 2015 from changes in aerosols and gases on climate and the hydrological cycle or vice versa. Tropospheric ozone and its precursors in the model has been evaluated and compared to observations in a couple of recent studies [Savage et al., 2003; Isaksen et al., 2005]. The model was able to reproduce the main features and distributions of ozone and its precursors. The best correspondence was found at unpolluted and semipolluted sites. [36] The changes in acid deposition is very dependent on the accuracy of the sulfur and deposition scheme which is discussed and evaluated in more detail by Berglen et al. [2004]. Berglen et al. [2004] found that the model results agree well with observations overall, but that the model tends to overestimate SO 2 and underestimate sulphate in the Northern Hemisphere winter. As can be seen from Figure 1 the fairways for Norwegian coastal shipping are really close to the coast and this will pose some uncertainties when the emissions are interpolated to the resolution of the CTM runs. It seems that some of the emissions will happen in model grid boxes touching land. However, we do not think this has a large impact on our calculations and conclusions. Unresolved topography and circulation patterns like the land sea breeze are more likely to affect the interpretation of the results. Therefore some of the regional discussions, for instance those connected to coastal effects in Norway 16 of 30

17 Figure 11. Increase in surface SO 2 in July due to year 2000 Norwegian coastal traffic. only give an indication of the magnitude and sign of concentration changes. [37] The setup of the CTM model simulations and the emission data included in each run is shown in Table 7. An overview of the emissions inventories were given in Table 1. The effects are quantified on the basis of differences between simulations with and without the emission inventories of interest included. In all the simulations in this study the model was run for 15 months and results for the 12 last months were analyzed allowing for a spin-up time of 3 months. In the CTM calculations we quantify the effects on levels of ozone (climate, pollution), sulfate (acidification, climate), nitrate (acidification), NO x (pollution, precursor ozone and nitrate), NMVOCs (pollution, precursors ozone), SO 2 (pollution, precursor sulfate), OH and its effect on methane (climate), and aerosols (pollution, climate). 4. Results [38] In section 4.1 we quantify the impact of all ship emissions for year Since we introduce a new emission data set, we also do a separate calculation on the effect of Norwegian coastal ship emissions (section 4.2). The effects of sea transportation and offshore activity scenarios toward 2015 (described in section 2) are then discussed in a global context (section 4.3). We discuss the regional impact of new coastal gas power plants, NSR transits and increasing oil and gas transportation in northern areas in 2015 in section 4.4. In section 4.5 we evaluate a sensitivity study of ship impact in 2015 using an assumption about changed nonship emissions from 2000 to Impact of All Ship Emissions in 2000 [39] In this section we focus on the differences between a simulation with and without ship emissions for year 2000, the so-called ALLSHIP and NOSHIP simulations respectively in Table 7. In Figure 4 we compare the results from the two simulations with observations of surface ozone and NO 2 available from the World Datacenter of Greenhouse Gases (WDCGG) (Japan Meteorological Agency, Tokyo, Japan, available at The chosen observation sites are more or less impacted by marine air masses and situated in a coastal environment. Since we use transport data for 1996 and the emissions are supposed to represent year 2000, we compare with observations for these two years. If these years were not available the closest year to 2000 was picked. Available observations in ship impacted air are few and though the stations are not situated in regions of heavy traffic and within ship plumes the comparison should give some indications of the ability to simulate the impact of ship emissions. The model reproduces the observed ozone reasonably or well at several stations. In the Southern Hemisphere the model tends to underestimate the ozone build up during the spring. Likely causes for this are probably not related to ship emissions but an underestimation of the transport from the stratosphere or 17 of 30

18 Figure 12. Increase in surface ozone in July due to year 2000 Norwegian coastal traffic. effect of biomass burning during the fire season. Though capturing the seasonality, the model also overestimates ozone at some of the stations close to the outflow regions of polluted areas in eastern North America and eastern Asia. This might be a resolution issue as the large grid boxes in the model may contain polluted air masses whereas the observation sites are measuring mostly background air. The ozone levels during the summer season are too high in the model in the eastern North Sea and the western Baltic Sea. The model results correspond better when the ship emissions are turned completely off, but there is without doubt ship traffic in the area. It is possible that the model overestimates the effects of ship emissions and other sources in the region, though it might also be due to an unknown insufficiency in regional boundary layer chemistry as there is a strange build up of modeled NO 2 in the summer at these stations. At stations in other regions the simulated seasonality and levels of NO 2 are reasonable. [40] Overall the impacts of ship emissions are quite similar to what we obtained in an earlier study Endresen et al. [2003], but the effects of improvements like higher model resolution, coupled oxidation and sulfur chemistry and inclusion of carbonaceous aerosols are discussed. Increases in ozone levels due to ship emissions are largest in July (Figure 5) when sufficient sunlight results in an active photochemistry and a significant ozone production in the northern hemisphere over large regions including coastal areas. In regions with large traffic (the North Sea, fishing docks west of Greenland, the Channel, the western Mediterranean, the Suez Channel, the Persian Bay), increases above 10 ppbv are found. The effect on ozone shows a profound seasonality. Along the Norwegian coast and Arctic areas to the north, our main focus region in the scenario studies, the summer impacts of ship emissions are substantial. The ozone photochemistry at high latitudes is very dependent on the availability of sunlight but changes are also driven by the traffic pattern with more traffic in the summer seasons. The shift in traffic pattern with season can to some extent be seen in the changes (Figure 6) of a shortlived component like NO 2. The highest surface increase is found around the North Sea and the Channel. NO 2 is more than doubled along the major world shipping lanes. A typical increase in the NO 2 column (not shown) along the same lanes is 30 70%. The ship emissions have an effect on ozone also at higher altitudes and thereby radiative forcing. Ozone produced in the boundary layer or produced during the transport process is lifted by convection and frontal systems to higher altitudes where the lifetime is longer and transport faster. At high latitudes in winter/spring when the lifetime in these regions is long ozone transported into the area tends to accumulate. These patterns can be seen in the plots of column changes (Figure 7). Tropospheric column increases are typically 2 6 Dobson Units in the most impacted regions. The highest increase in all seasons is 18 of 30

19 Figure 13. Increase in wet deposition of nitrate in October due to year 2000 Norwegian coastal traffic. found near the Persian Bay. Sufficient sunlight and background concentration levels of NO x and hydrocarbons make the conditions favorable for efficient ozone production. The emissions from ship traffic in the area are large, in particular emissions of hydrocarbons due to evaporation of crude oil from tankers [Endresen et al., 2003, Figure 3]. Typical relative tropospheric column increases (not shown) are 7% to 14% in the northern hemisphere and 2 7% in the southern hemisphere. [41] In this study we find that ship emissions increase the global averaged OH by 0.64%. The corresponding methane lifetime decreases by 1.48%. The higher OH perturbation and values of methane near the surface as well as the temperature dependency of the reaction rate make methane oxidation more sensitive to changes in the lower troposphere than at higher altitudes. These values are lower than what we found in our earlier study Endresen et al. [2003] and could be explained by the increase in model resolution for this study. Higher resolution leads to less smoothing and more efficient removal of NO x in the shipping lanes. The NO x increase is also lower than what we found in our previous study. [42] In Figures 8 and 9 the impact of ship emissions on wet deposition of nitrate and sulfate is shown. These are major components of acid rain. The largest increases can be seen in seasons with much rainfall on the west coast of the continents where westerly winds often prevail. Parts of Scandinavia are vulnerable to acid precipitation due to slowly weathering bedrock. The impact on this region is large with an increase of up to 30 50% in nitrate wet deposition and 10 25% in sulfate wet deposition. Coastal countries in western Europe, northwestern America and partly eastern America are substantially impacted with relative increases between 5% and 50%. The relative impact on dry deposition of SO 2 and nitrogen (not shown) is of roughly similar magnitude to the wet deposition but levels off faster inland because of the shorter lifetime of these components in the boundary layer. For SO 2 a reduction in dry deposition is also found over some areas at some distance from the shipping lanes because of increased SO 2 oxidation by increasing OH. [43] The maximum relative sulfate column increase is 14% and the pattern is similar to the wet deposition of sulfate (Figure 9) with the largest increase over the Atlantic and the North Pacific. At the surface the ship emissions increase significantly sulfate aerosols over oceanic areas and coastal near regions. Sulfate has been shown to be an important contributor to the aerosol amount and occasions of haze in the Arctic [Koch and Hansen, 2005; Rinke et al., 2004; Shaw, 1995]. This can be attributed to transport from continental sources. These results suggest that ship emissions also to some extent contribute. An interesting aspect is that some regions show a decrease both in SO 2 and sulfate due to ship emissions. We find a reduction of SO 2 in the upper troposphere in these regions that is a result of 19 of 30

20 Figure 14. NO 2 surface change in 2015 due to all ship emissions and new Norwegian coastal gas power plants for the months (top left) January, (top right) April, (bottom left) July and (bottom right) October. increased oxidation by O 3, H 2 O 2 and OH over larger regions outside the shipping lanes. In regions dominated by dry conditions and subsidence we also find a decrease in sulfate due to both reduced OH and SO 2. A decrease in OH in remote regions in the upper troposphere can be explained by the short lifetime of ship induced NO x perturbations outside the marine boundary layer. Because of the much longer lifetime of CO and hydrocarbon perturbations, OH over some remote regions decrease leading to less oxidation of SO 2 to sulfate. The increase in carbonaceous aerosols (not shown) is also substantial. Over the remote oceans far from land sources, carbonaceous aerosol amounts are low but the relative increase by ship traffic is very large Effect of Inclusion of Norwegian Coastal Ship Emissions in 2000 [44] Our analysis points to international ship emissions as the dominant ship source of pollutants in Norwegian coastal areas. However, the emissions from Norwegian coastal ship traffic contribute significantly to some primary pollutants like SO 2 and NO x. In particular the increases in NO x concentrations due to coastal traffic are quite large. Coastal ship emissions are responsible for more than 1/3 of Norway s total NO x emissions. As can be seen from the changes in NO 2 surface concentrations in Figure 10, relative increases are in the range 20 to more than 50% in the most affected areas when these emissions are included. The effect on SO 2 (Figure 11) is lower but still around 5 15%. The effect on ozone is small. In July (Figure 12) the increase is around 1 2% and even a small decrease is found during late autumn and winter when little sunlight leads to inefficient radical production so that loss of ozone in the reactions O 3 + NO and O 3 +NO 2 dominate. In October, one of the months with large effect of wet deposition from the total ship traffic (Figure 8) Norwegian coastal traffic increase the nitrate wet deposition (Figure 13) by more than 3%. This could be an important addition to vulnerable regions in Scandinavia where current critical loads are exceeded. On average onshore winds dominate most of the coast and the monthly averaged changes therefore often show larger increases a little inland, in particular for secondary formed species Effect of Ship Emissions and New Norwegian Coastal Gas Power Plants in 2015 [45] On the basis of our assumptions about ship traffic and fuel consumption (section 2) we have made scenario 20 of 30

21 Figure 15. Ozone surface change in 2015 due to all ship emissions and new Norwegian coastal gas power plants for the months (top left) January, (top right) April, (bottom left) July and (bottom right) October. Figure 16. Ozone surface change (ppbv) in 2015 due to all ship emissions and new Norwegian coastal gas power plants for 24 June, 1200 UT. 21 of 30

22 Figure 17. SO 2 surface change in 2015 due to all ship emissions and new Norwegian coastal gas power plants for the months (top left) January, (top right) April, (bottom left) July and (bottom right) October. runs to study the impact changes in Below we discuss the difference between the simulations SCENARIO2015 and ALLSHIP listed in Table 7. The SCENARIO2015 run contains all the emission data sets for 2015 and ALLSHIP includes all sources for [46] Figure 14 shows an approximately 15% increase of surface NO 2 in many ship lanes. This is about the same magnitude as the emission increase. Some areas like the North Sea, Baltic Sea, eastern US and Japan with high levels of NO x due to large anthropogenic emissions from several sources show a lower increase due to nonlinear chemistry and faster NO x removal. The oil and gas transportation from the Barents area and the Northern Sea Route is clearly visible on the NO 2 maps. These emissions add to the background increase from ship traffic and leads a to more than 20% increase in the most impacted regions. It should be noted that the absolute increases along the Northern Sea Route is low in this pristine region. [47] Monthly mean ozone increases at the surface in 2015 are typically 3 8% over oceanic regions and Scandinavia in July (Figure 15) and lower in other seasons. The increases in ozone column values are typically around 1%. A specific situation for 24 June, 1200 UT is presented in Figure 16 when ship emissions lead to a substantial increase in regions with high background ozone levels. Over northern continental Europe and southern Greece the increases are around 3 5%. The SO 2 change (Figure 17) does not scale linearly with the emission change. Increase in oxidants result in more SO 2 destruction. The typical increases at sea and at the coasts are 5 25%. The limit on sulfur fuel content to 1.5% in the North Sea and the English Channel is evident also in nearby countries. In these regions SO 2 levels are reduced by more than 10%. [48] Increasing wet deposition of nitrate and sulfate (Figures 18 and 19) of up to 10% is important with regard to acidification in sensitive areas. The increase in nitrate wet deposition is larger and shifted northward compared to the sulfate deposition. The effect of regulated SO 2 emissions can be seen in the sulfate deposition plot for July when the wet deposition over southern Scandinavia is reduced. [49] Even if legislations lead to smaller increases in NO x emissions than for components contributing to OH loss there is an increase in global averaged OH of 0.17%. This 22 of 30

23 Figure 18. Nitrate wet deposition change in 2015 due to all ship emissions and new Norwegian coastal gas power plants for the months (top left) January, (top right) April, (bottom left) July and (bottom right) October. results in a reduction of 0.41% in the global averaged methane lifetime Effect of New Norwegian Coastal Gas Power Plants, Northern Sea Route Transits, and Increasing Oil and Gas Transport From Norway and Northwest Russia in 2015 [50] New activity in the northern and Arctic areas may have significant regional effects. Figure 20 shows the additional 2015 increase in NO 2 due to the new activities. Increases are above 25% in parts of the oil and gas transport lanes in the Atlantic and along the coast of northern Scandinavia. The new activity in this area will dominate the NO 2 changes over the changes due to general ship emissions increase in 2015 (section 4.3). The changes in ozone due to increasing offshore activity, NSR and oil and gas transportation are modest. Increases in July (Figure 21) are up to 4% or about 1 ppbv on the north coast of Scandinavia. In October (Figures 22 and 23) increases in acid precipitation in affected areas is typically 1 4% with the highest values again in northern Norway. In July (not shown) the sulfate deposition is taking place more over land in northern Norway and the Kola Peninsula increasing the load here with 3 4%. This is a relative low number but might be of importance since this region have been suffering from vegetation damages due to regional industrial activity and it is noted that future pollutant levels need to be reduced to obtain recovery [SFT, 2002]. For sensitive vegetation critical levels of SO 2 have been exceeded over an area of 3200 km 2. Significant surface water acidification has occurred especially on the Norwegian side. On the other side of the border close to the smelters nickel and copper pollution is more severe. Air pollution has to some extent reduced invertebrates, fish and animal diversity because of its impact on vegetation, soils and water [SFT, 2002]. Despite recent reductions present emissions of heavy metals and SO 2 from the smelter in Nikel and the roasting plant in Zapolyarny are still above the critical levels for sensitive biota [SFT, 2002]. [51] As an example of changes in aerosols we show hydrophobic organic carbon at the surface in July (Figure 24). Again it is evident, with more than a 15% increase, that 23 of 30

24 Figure 19. Sulfate wet deposition change in 2015 due to all ship emissions and new Norwegian coastal gas power plants for the months (top left) January, (top right) April, (bottom left) July and (bottom right) October. ships and the new activity in particular may contribute substantially to the particle amounts and haze in the Arctic Sensitivity Study Including Changes in Nonship Anthropogenic Emissions in 2015 [52] The responses of some tropospheric constituents, in particular ozone, to changes in precursor emissions are sometimes nonlinearly dependent on the background concentrations of precursors. Future perturbations due to ship emissions might therefore be significantly affected by changes in other emission sources. The IPCC special report on emission scenarios [Nakicenovic et al., 2000] concludes that there is no single most likely or recommended emission scenario in the literature and in the results discussed so far we made an assumption of no changes in nonship emissions. However, we did a sensitivity study where the trends in the emissions of anthropogenic nonship ozone precursors CO, NO x and NMVOCs for the period were assumed to continue until In this case there are large regional differences in the emission trends. The changes in emissions of CO and NO x in the period for several world regions are listed in Table 1 in Dalsøren and Isaksen [2006]. Figure 25 shows the changes in surface ozone for July from 2000 to 2015 when both increasing ship traffic and the assumed changes in other anthropogenic emissions are taken into account. There is a large absolute increase in ozone over Asia due to a raise in emissions from land based sources. Over most of continental Europe a decrease in anthropogenic emissions results in reduced ozone amounts. Over most of the oceans and coastal areas a small but significant increase in ozone is found. Signs of impact from ship traffic can be discerned along the Norwegian coast, eastern Greenland, west and east coast of North America, west coast of South America and around Gibraltar. Figures 26 and 27 show the contribution of all ship traffic to surface ozone in July 2015 with no changes in other emissions and changes as in the above described sensitivity run respectively. Even if the background concentrations of precursors differ the contribution of ship traffic to surface ozone is significant and very similar in the two cases. 5. Conclusion [53] In this study we calculated the current global (year 2000) and future (year 2015) impact on atmospheric composition and deposition of sea transportation emissions with 24 of 30

25 Figure 20. NO 2 change in July 2015 at the surface due to new Norwegian coastal gas power plants, NSR and oil and gas transport from Norway and northwest Russia. a Chemical Transport Model (CTM). Compared to an earlier study [Endresen et al., 2003] we have made several improvements in the input data for 2000 and the CTM formulation. The simulations was made with higher spatial resolution, coupled sulfur and oxidant chemistry, inclusion of a data set for Norwegian coastal ship emissions, updated emission data sets for nonship sources and inclusion of carbonaceous aerosols. Figure 21. Ozone change in July 2015 at the surface due to new Norwegian coastal gas power plants, NSR and oil and gas transport from Norway and northwest Russia. 25 of 30

26 Figure 22. Sulfate wet deposition change in October 2015 due to new Norwegian coastal gas power plants, NSR and oil and gas transport from Norway and northwest Russia. [54] Statistics show that current Norwegian coastal ship emissions are responsible for about 40% of the national NO x emissions, 17% of SO 2,9%ofCO 2 and roughly 1% of CO, NMVOCs and PM. On the basis of movement data for Norwegian fairways we developed a gridded data set for these emissions to study their regional atmospheric impact. For most components the international fleet is the dominant source. However, the emissions from the Norwegian coastal Figure 23. Nitrate wet deposition change in October 2015 due to new Norwegian coastal gas power plants, NSR and oil and gas transport from Norway and northwest Russia. 26 of 30

27 Figure 24. Hydrophobic organic carbon change in July 2015 at the surface due to new Norwegian coastal gas power plants, NSR and oil and gas transport from Norway and northwest Russia. traffic are regionally important for primary pollutants like SO 2 and NO x, and to some extent wet deposition of nitrate. As our former study indicated we find that the ship fleet contributes significantly to tropospheric ozone. Maximum surface increases due to ship emissions in the summer in the northern hemisphere are above 10 ppbv and increases are substantial in some coastal areas. The tropospheric column increase in the most impacted regions is 2 6 DU. Typical tropospheric column increases are 7 14% in the northern hemisphere and 2 7% in the southern hemisphere. Our calculations show further that current global ship emissions have a significant effect on wet deposition of acidic components. The increase of wet deposition of nitrate and sulfate over Scandinavia is 30 50% and 10 25%, respectively. Several places with prevailing onshore winds show enlargement in deposition of these components above 5%. Figure 25. Ozone surface change from July 2000 to 2015 from a sensitivity study including both changes in ship emissions and land based anthropogenic sources. 27 of 30