[en] The Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL) has been prompted to produce the series Trends, a concise inventory of data in response to heightened concern about global environmental issues, in particular climate changes induced by the greenhouse effect. This report contains extracts from Trends '91 to illustrate the content, style, and presentation of data contained in the full 700-page report. This report includes a listing of the investigators contributing data for Trends '91. In addition, it contains the abstract, foreword, and acknowledgments, as well as the introduction and a sample data record from each of the reports's five chapters. The chapters are ''Atmospheric CO₂,'' ''Atmospheric CH₄,'' ''Other Trace Gases,'' ''CO₂ Emissions,'' and ''Temperature.'' Appendix A provides information about CDIAC and its activities related to global environmental issues. Appendix B lists the contents of the full report. An order form for obtaining a free copy of Trends '91 is found in Appendix C