This is a pre-release of the harmonized ScenarioMIP emissions data. Please refer to the Rules for data use and data sharing of the IAM ScenarioMIP Data at https://scenariomip.apps.ece.iiasa.ac.at. Harmonized Emissions of the IAM ScenarioMIP projections for CMIP7 ScenarioMIP-CMIP7 consists of alternative plausible futures including quantified emissions and land use projections. The primary objectives of ScenarioMIP are to: Facilitate integrated research leading to a better understanding of the physical climate system consequences of future scenarios and their impact on natural and social systems, including adaptation and mitigation considerations. Provide a basis for addressing targeted science questions about the climate effects of aspects of forcing relevant to scenario-based research. Provide a basis for various international efforts that target improved methods to quantify projection uncertainties based on multi-model ensembles. ScenarioMIP is part of the Coupled Model Intercomparison Project organised by the World Climate Research Programme, and integrates research across the climate science, integrated assessment modeling (IAM), mitigation, and impacts, adaptation and vulnerability (IAV) communities. Seven IAM teams participated in the scenario development process. Each scenario has been implemented with multiple IAMs, and a marker scenario was selected from the available model interpretations. The current pre-release comprises the harmonized emissions of the marker scenarios only. Harmonized emissions of additional non-marker quantifications will follow. This pre-release hosts limited data, with the publication of more data variables to follow. The available data are the emissions variables that have gone into the climate emulator MAGICC and its climate outcomes. The reported emissions variables are harmonized to CMIP7 historical emissions, and consistent with CMIP7 earth system model forcings: GHG concentrations and gridded emissions, as available on the Earth System Grid Federation (see input4MIPs: https://input4mips-cvs.readthedocs.io/en/latest/). For more information, please contact: Scientific Lead: Keywan Riahi (IIASA, riahi@iiasa.ac.at), Detlef van Vuuren (PBL, Detlef.vanVuuren@pbl.nl) Emissions harmonization and infilling for CMIP7: Jarmo Kikstra (IIASA, kikstra@iiasa.ac.at), Zebedee Nicholls (Climate Resource, IIASA, Uni Melbourne, zebedee.nicholls@climate-resource.com) ScenarioMIP IAM marker teams: High Emissions Pathway (H) developed by GCAM: Mel George, Christoph J. Bertram, Andrew G. Miller, Xin Zhao, Claudia Rodes Bachs, Jay Fuhrman, Rachel Hoesly, Haewon C. McJeon, Brian O'Neill, Yang Ou, Jon Sampedro, Steven J. Smith, Dirk-Jan Van de Ven, Matt Gidden, Ryna Cui (CGS-UMD [Center for Global Sustainability, School of Public Policy, University of Maryland, College Park, Maryland, USA], KAIST, BC3, Peking University) High-to-Low Emissions Pathway (HL) developed by WITCH: Laurent Drouet, Lara Aleluia (CMCC) Medium Emissions Pathway (M) developed by IMAGE: Detlef van Vuuren, Vassilis Daioglou (PBL) Medium-to-Low Emissions Pathway (ML) developed by COFFEE: Roberto Schaeffer, Luiz Bernardo Baptista, Gerd Angelkorte (COPPE)This pathway is still in development and will be included in a later release. Low Emissions Pathway (L) developed by MESSAGE-GLOBIOM-GAINS: Oliver Fricko, Volker Krey, Keywan Riahi (IIASA) Very Low Emissions Pathway (VL) developed by REMIND-MAGPIE: Elmar Kriegler, Laurin Köhler-Schindler, Florian Humpenöder (PIK) Low-to-Negative Emissions Pathway (LN) developed by AIM: Shinichiro Fujimori, Tomoko Hasegawa (Kyoto University) Air pollution: please contact Shaohui Zhang, Zbigniew Klimont (IIASA)