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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-2026-1673</article-id>
<title-group>
<article-title>Land carbon response to positive, zero, and negative CO&lt;sub&gt;2&lt;/sub&gt; emissions across Earth system models</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Swann</surname>
<given-names>Abigail L. S.</given-names>
<ext-link>https://orcid.org/0000-0001-8513-1074</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 contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Koven</surname>
<given-names>Charles D.</given-names>
<ext-link>https://orcid.org/0000-0002-3367-0065</ext-link>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Proistosecu</surname>
<given-names>Cristian</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Fisher</surname>
<given-names>Rosie A.</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Sanderson</surname>
<given-names>Benjamin M.</given-names>
<ext-link>https://orcid.org/0000-0001-8635-4624</ext-link>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Brovkin</surname>
<given-names>Victor</given-names>
<ext-link>https://orcid.org/0000-0001-6420-3198</ext-link>
</name>
<xref ref-type="aff" rid="aff7">
<sup>7</sup>
</xref>
<xref ref-type="aff" rid="aff8">
<sup>8</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Hajima</surname>
<given-names>Tomohiro</given-names>
</name>
<xref ref-type="aff" rid="aff9">
<sup>9</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Jones</surname>
<given-names>Chris D.</given-names>
<ext-link>https://orcid.org/0000-0002-7141-9285</ext-link>
</name>
<xref ref-type="aff" rid="aff10">
<sup>10</sup>
</xref>
<xref ref-type="aff" rid="aff11">
<sup>11</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kiang</surname>
<given-names>Nancy Y.</given-names>
</name>
<xref ref-type="aff" rid="aff12">
<sup>12</sup>
</xref>
<xref ref-type="aff" rid="aff13">
<sup>13</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Lawrence</surname>
<given-names>David M.</given-names>
<ext-link>https://orcid.org/0000-0002-2968-3023</ext-link>
</name>
<xref ref-type="aff" rid="aff14">
<sup>14</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Liddicoat</surname>
<given-names>Spencer</given-names>
</name>
<xref ref-type="aff" rid="aff11">
<sup>11</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Liddy</surname>
<given-names>Hannah</given-names>
</name>
<xref ref-type="aff" rid="aff13">
<sup>13</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Romanou</surname>
<given-names>Anastasia</given-names>
<ext-link>https://orcid.org/0000-0001-5241-4772</ext-link>
</name>
<xref ref-type="aff" rid="aff12">
<sup>12</sup>
</xref>
<xref ref-type="aff" rid="aff15">
<sup>15</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Séférian</surname>
<given-names>Roland</given-names>
<ext-link>https://orcid.org/0000-0002-2571-2114</ext-link>
</name>
<xref ref-type="aff" rid="aff16">
<sup>16</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Sentman</surname>
<given-names>Lori T.</given-names>
<ext-link>https://orcid.org/0000-0003-1954-5564</ext-link>
</name>
<xref ref-type="aff" rid="aff17">
<sup>17</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Steinert</surname>
<given-names>Norman J.</given-names>
<ext-link>https://orcid.org/0000-0002-2154-5857</ext-link>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Tjiputra</surname>
<given-names>Jerry</given-names>
<ext-link>https://orcid.org/0000-0002-4600-2453</ext-link>
</name>
<xref ref-type="aff" rid="aff18">
<sup>18</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ziehn</surname>
<given-names>Tilo</given-names>
<ext-link>https://orcid.org/0000-0001-9873-9775</ext-link>
</name>
<xref ref-type="aff" rid="aff19">
<sup>19</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Department of Atmospheric and Climate Science, University of Washington, Seattle, WA, USA</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Department of Biology, University of Washington, Seattle, WA, USA</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Lawrence Berkeley National Laboratory, Berkeley, USA</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Department of Climate, Meteorology, and Atmospheric Science, University of Illinois Urbana Champaign, Urbana, IL, USA</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Department of Earth Sciences and Environmental Change, University of Illinois Urbana Champaign, Urbana, IL, USA</addr-line>
</aff>
<aff id="aff6">
<label>6</label>
<addr-line>CICERO International Center for Climate Research, Oslo, Norway</addr-line>
</aff>
<aff id="aff7">
<label>7</label>
<addr-line>Max Planck Institute for Meteorology, Hamburg, Germany</addr-line>
</aff>
<aff id="aff8">
<label>8</label>
<addr-line>University of Hamburg, Hamburg, Germany</addr-line>
</aff>
<aff id="aff9">
<label>9</label>
<addr-line>Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan</addr-line>
</aff>
<aff id="aff10">
<label>10</label>
<addr-line>School of Geographical Sciences, University of Bristol, UK</addr-line>
</aff>
<aff id="aff11">
<label>11</label>
<addr-line>Met Office Hadley Centre, Exeter, UK</addr-line>
</aff>
<aff id="aff12">
<label>12</label>
<addr-line>NASA Goddard Institute for Space Studies, New York, NY, USA</addr-line>
</aff>
<aff id="aff13">
<label>13</label>
<addr-line>Center for Climate Systems Research, Columbia University, New York, NY, USA</addr-line>
</aff>
<aff id="aff14">
<label>14</label>
<addr-line>NSF National Center for Atmospheric Research, Boulder, CO, USA</addr-line>
</aff>
<aff id="aff15">
<label>15</label>
<addr-line>Dept. Applied Phys. Applied Math., Columbia U., New York, NY, USA</addr-line>
</aff>
<aff id="aff16">
<label>16</label>
<addr-line>Météo-France, CNRS, Univ. Toulouse, CNRM, Toulouse, France</addr-line>
</aff>
<aff id="aff17">
<label>17</label>
<addr-line>NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA</addr-line>
</aff>
<aff id="aff18">
<label>18</label>
<addr-line>NORCE Research AS, Bjerknes Centre for Climate Research, Bergen, Norway</addr-line>
</aff>
<aff id="aff19">
<label>19</label>
<addr-line>CSIRO Environment, Aspendale, Australia</addr-line>
</aff>
<pub-date pub-type="epub">
<day>08</day>
<month>04</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>49</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Abigail L. S. Swann 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-2026-1673/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1673/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1673/egusphere-2026-1673.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1673/egusphere-2026-1673.pdf</self-uri>
<abstract>
<p>Land carbon sinks are responsible for removing about a quarter of anthropogenic CO&lt;sub&gt;2&lt;/sub&gt; emissions, and make up approximately half of total global carbon sinks. Uncertainty in the response of land carbon sinks to climate and changing atmospheric CO&lt;sub&gt;2&lt;/sub&gt; are large, and dominate the uncertainty in total carbon sinks under future climate. Understanding the carbon cycle response to net-zero and net-negative emissions has important implications for projecting future climate. Experiments in the &quot;flat10&quot; model intercomparison were designed for directly estimating key climate metrics that underlie carbon budgeting frameworks. Here we characterize the response of land carbon pools and fluxes from ten emissions-driven Earth system models (ESMs) under positive, net-zero, and net-negative CO&lt;sub&gt;2&lt;/sub&gt; emissions. Although there are many differences in simulated land carbon pools and fluxes across models, we find some consistent behavior across ESMs. 1) During the positive emissions phase, carbon is gained on land primarily in vegetation pools. 2) Following net-negative emissions to the point of cumulative zero emissions, carbon is lost from land in tropical latitudes, primarily from vegetation pools, but in mid- and high-latitudes most models show net land carbon gain, primarily in soil pools. 3) Following an extended period of net-zero emissions, a majority of models again show carbon gain in mid- and high-latitudes and vegetation carbon loss in the tropics. Under net-negative emissions the timing of vegetation carbon response relative to peak emissions is relatively consistent across ESMs, but timing of soil carbon response varies widely, implying larger intermodel disagreement associated with responses of soil carbon which tends to have longer timescales relative to vegetation carbon. Our findings highlight that tropical carbon is most likely to be both gained and subsequently lost under positive, zero, declining, and negative emissions, with possible implications for carbon dioxide removal efforts.</p>
</abstract>
<counts><page-count count="49"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>National Science Foundation</funding-source>
<award-id>AGS-2330096</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
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