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<front>
<journal-meta>
<journal-id journal-id-type="publisher">EGUsphere</journal-id>
<journal-title-group>
<journal-title>EGUsphere</journal-title>
<abbrev-journal-title abbrev-type="publisher">EGUsphere</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">EGUsphere</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub"></issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/egusphere-2026-1935</article-id>
<title-group>
<article-title>Addressing systemic underestimation in global ship emissions from fleet growth and fuel compliance</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zhang</surname>
<given-names>Weiwei</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Lv</surname>
<given-names>Zhaofeng</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Yi</surname>
<given-names>Wen</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>He</surname>
<given-names>Tingkun</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Xiao</surname>
<given-names>Bensheng</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zhang</surname>
<given-names>Qiang</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Liu</surname>
<given-names>Huan</given-names>
<ext-link>https://orcid.org/0000-0002-2217-0591</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>State Key Laboratory of Regional Environment and Sustainability, School of Environment, Tsinghua University, Beijing 100084, China</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Institute for Carbon Neutrality, Tsinghua University, Beijing 100084, China</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China</addr-line>
</aff>
<pub-date pub-type="epub">
<day>26</day>
<month>05</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>19</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Weiwei Zhang et al.</copyright-statement>
<copyright-year>2026</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1935/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1935/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1935/egusphere-2026-1935.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1935/egusphere-2026-1935.pdf</self-uri>
<abstract>
<p>As a hard-to-abate sector, global shipping is under international and regional emission control regulations. To evaluate emission control effects and conduct rapid response air quality simulations, accurate and timely ship emission inventories are indispensable. However, current ship emission inventory models face multiple challenges, including incomplete and delayed global ship fleet description and significant divergence in PM&lt;sub&gt;2.5&lt;/sub&gt; emissions after global low sulfur regulation came into effect. Here, we established a dynamically updated Ship Emission Inventory Model that allows near-real-time emission calculation. Ship activity and technical database are updated daily instead of yearly to obtain a more complete and rapid description of global ship fleet. Fleet&apos;s multiple choices to comply with fuel sulfur regulation were considered, including switching to very low sulfur fuel and utilizing scrubbers to keep consuming heavy fuel oil. The daily expansion of ship technical database uncovered 8% and 6.2% of the total gross tonnage of active bulk carrier and container fleets, unveiling up to 5.4% of global ship CO&lt;sub&gt;2&lt;/sub&gt; emissions. Without the expansion, the daily underestimation would enlarge over time from about 0.20 Mt CO&lt;sub&gt;2&lt;/sub&gt;/d to 0.29 Mt CO&lt;sub&gt;2&lt;/sub&gt;/d throughout 2024. On the other hand, the single compliance choice assumption and ignorance of heavy fuel oil use after 2020 would lead to underestimation of PM&lt;sub&gt;2.5&lt;/sub&gt; and BC emissions by approximately 55% and 27%. Although South China Ocean had the most absolute underestimation, the Indian Ocean had the highest underestimated portion, reaching 75% and 39% of its total PM&lt;sub&gt;2.5&lt;/sub&gt; and BC emissions.</p>
</abstract>
<counts><page-count count="19"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>National Key Research and Development Program of China</funding-source>
<award-id>2023YFC3705604</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
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