FrontMatter -- Preface -- Acknowledgments -- Contents -- Executive Summary -- 1 Why an International Polar Year in 2007-2008 -- 2 Scientific Challenges for the International Polar Year -- 3 Understanding Change in the Polar Regions -- 4 Exploring Scientific Frontiers -- 5 Technology to Enable Innovative Observations -- 6 Increasing Public Understanding and Participation in Polar Science through the International Polar Year -- 7 Actions Needed to Make the International Polar Year Succeed -- References -- APPENDIXES -- APPENDIX A International Partners in IPY 2007-2008 -- APPENDIX B Biographical Sketches of Committee Members -- APPENDIX C Acronyms and Abbreviations.