This data project has been published in parallel to Mildenberger, M. 2020. Carbon Captured: How Business and Labor Control Climate Politics (Cambridge, MA: MIT Press). In this book, I advance a new theory to explain cross-national differences in the timing and content of climate reforms across advanced industrial economies. This book seeks to make the sources of its inferences as transparent as possible. In doing so it draws from best practices outlined by the American Political Science Association in its 2012 Council Statement on Openness in Political Science and in a 2013 Guideline for Data Access and Research Transparency for Qualitative Research in Political Science. This data project and its associated Transparency Appendix (TRAX) are key components of this effort. Where permitted by copyright, the data project provides digital copies of grey literatures, policy documents, and media reports referenced in the book or in the book's Transparency Appendix. Where copyright issues are involved (e.g. with respect to news clippings) I instead provide permanent web archives for each of these media clippings using the perma.cc service.