Observed changes in natural systems, largely over the past century, indicate a clear global climate change signal. Even in the face of apparently dominating forces, such as direct, human-driven habitat destruction and alteration, this climate fingerprint implicates global climate change as a new and important driving force on wild plants and animals. Patterns across taxonomic groups are remarkably similar. Large poleward and upward range shifts associated with recent global climate change have been documented in a diversity of species. Likewise, significant trends towards earlier spring events have been documented in plants and animals across North America, Europe and Asia. These changes in species’ distributions and timing have been linked with regional climate warming for many species based on basic research and on long-term historical records. Our recent estimate is that about half of all wild species have responded to regional warming trends of 1-3° C over the past century, with strongest responses over the past 30 years. In the Third Assessment Report of IPCC (2001), we predicted that species restricted to extreme environments, such as mountaintops, the Arctic and Antarctic, would be most sensitive to small levels of warming and, indeed, these areas are showing the first signs of species declines and extinctions. Range-restricted species, particularly polar and mountaintop species, are showing severe range contractions in response to recent climate change. Tropical coral reefs and sea ice specialists have been most negatively affected, with indications that cloud forest amphibians are also highly vulnerable. New analyses indicate large differences in magnitude of spring advancement between major taxonomic groups, suggesting that normal interactions among species, such as flowers and the insects that pollinate them may become disrupted. Evolutionary adaptations to warmer conditions have occurred at the local, population level, but observed genetic shifts are limited. There is no indication that novel traits are appearing that would allow species to exist under more extreme climatic conditions than they currently live in. Dr. Parmesan’s early research spanned multiple aspects of the behavior, ecology and evolution of insect/plant interactions in natural systems. Since 1992, however, the focus of her work has been on biological impacts of anthropogenic climate change in natural systems. Her field work has focused on documenting continental-scale range shifts of butterfly species across both North America and Europe. Her more recent research has concentrated on global-scale syntheses of biological responses to climate change across all taxonomic groups. These syntheses have documented the global nature of climate change impacts, spanning all living organisms from microbes to charismatic animals in terrestrial, freshwater and marine systems. The intensification of global warming as an international issue led Dr. Parmesan into the interface of policy and science. She has given presentations for White House and Congressional representatives, has been involved in several U.S. and international assessments of climate change impacts, and has provided formal testimonies for the US House Select Committee on Energy Independence and Global Warming, as well as the Texas Senate Natural Resources Committee. She has also been active in climate change programs for many international conservation organizations, such as IUCN (the International Union for the Conservation of Nature), the WWF (World Wildlife Fund), and the National Wildlife Federation, and served on the Science Council of the Nature Conservancy. She was a Lead Author and Contributing author of the Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report (2001), as well as Reviewer and Co-author of the Uncertainty Guidance Report for the IPCC