This book presents 'human ecology economics' as a new and more comprehensive interdisciplinary framework for understanding 'world conditions and human systems'. This book helps economists rethink the boundaries and methods of their discipline - so that they can participate more fully in debates over humankind's present problems and on the ways that they can be solved. Authors contributing to this book agree that human ecology economics is a superior framework for responding to global sustainability concerns because, unlike traditional economics and other social sciences, it allows a long time run perspective, encourages use of the humanities, and effectively juxtaposes 'sustainability' and other interdisciplinary issues alongside traditional economic issues. The contributors explore the following types of questions: What drives innovation and evolution in the world economy? What allows the U.S. one-third of the world's wealth and a leadership role going into the twenty-first century? How can we better understand and address the causes of poverty, inequality, social conflict and inadequate food and energy supplies? Will responding to climate change and other concerns require changes in our ways of being? The book is written for the non-specialist as well as the professional economist in order to advance shared understanding of these 'challenges to humankind'. This book is relevant to courses in Economics, International Relations, Environmental Science and Studies, Ecology and Political Economy among others, and will also benefit any professional audience interested in world conditions and global concerns, including business people, non-profit organisations and governments.