We are now in an unprecedented age where humans have become a force of global importance and where local human behavior has significant global impacts. In light of this new world order, Dr. Richard Rockwell of the University of Michigan addresses the issue of identifying and mitigating the negative impacts of human activity on the environment. These impacts, which Dr. Rockwell describes as large and growing, are and will continue to affect every individual, regardless of whether they directly contribute to the impacts or not.

Much was left unsaid at the UNCED conference in Rio about the interactions among population growth, human deprivation, and resource use. Dr. Walter Falcon, director of Stanford's Institute for International Studies, develops these themes, drawing on his extensive knowledge of hunger, land use, and agriculture, and on his specific experiences in South and Southeast Asia.

Computer models are currently relied upon to provide estimates of possible future changes in the Earth's climate. Results from these models were at the center of the global warming debate at the recent Earth Summit in Brazil. There was a great deal of controversy about whether modeling can yield insights into the planet's future. In this talk, Dr. Warren Washington, researcher at the National Center for Atmospheric Research, comments on the climate research community's views and the skeptical response.

Sustainability is a contentious topic, attracting a variety of views from different interest groups. In the American West, disagreements over what is needed to achieve sustainable ecosystems often pit ranchers against environmentalists and makes progress on policy and management difficult. In this lecture, Rob Woodmansee, a range ecologist at Colorado State University, discusses the competing views of sustainability. Woodmansee argues, "what you see depends on where you sit," and suggests that achieving a sustainable future must recognize and understand the many different perspectives.

Of the many pressing global change issues, none have as far-reaching effects as biodiversity loss. In this eloquent and passionate talk, Dr. Norman Myers explains why biodiversity is a crucial environmental issue and tells of efforts to find solutions to the problem of species extinction. In his talk, Dr. Myers pays specific attention to tropical forests, where biodiversity is greatest but most at risk.

The field of global change science is a relatively young field, developing out of the recognition of the sizable impact humans are making on the planet. In this lecture, Robert Corell, assistant director of the National Science Foundation, provides an overview of the scope of global change science and touches on its major contributions. In addition, Corell offers some comments about policies that can address global change issues.