As the increasing intensity of human activities causes the climate to change, the temperatures, rainfall, storminess, sea levels and more that society and the natural world experience will be altered. Global warming during the 21st century is projected to be several times more than the 0.6ºC (1ºF) occurring over the 20th century; similarly, sea level rise by 2100 is projected to be a few times larger than the 10-20 cm (4-8 inches) occurring since 1900. What happened to the climate in the past and what changes are projected for the future changes as a result of combusting coal, oil, and natural gas and from disturbing the natural land cover are encompassed in summaries about the Science of Climate Change.

The consequences of changes in climate for society and the environment are referred to as the Impacts of Climate Change. These impacts can occur as a result of extreme fluctuations in the climate, such as the extreme heat and dry conditions of the Summer of 2003 that are leading to widespread fires in Europe and western North America. Ongoing global warming is also contributing to the disruption of Arctic ecosystems as sea ice becomes thinner and less extensive.

The compilation of materials available through this website documents that impacts are already occurring as a result of past changes in the climate and provide the best estimates of potential impacts resulting from the changes in climate available in leading scientific assessments. Because impacts vary from place-to-place, and because the vulnerability to these potential impacts depends on variations in the capabilities to adapt to and prepare for the changes, the most informative impact studies have focused on expectations for particular regions. For this reason, the materials presented here are organized by region, initially at the continental scale, and then more finely at scales of nations, subregions, and, in some cases, provinces and states. The many interconnections across regions and continents, for example, for agriculture and human health, require that potential impacts be evaluated over wide areas. For this reason, studies and reports are also grouped together for particular sectors.

There are an increasing number of studies and analyses of potential impacts and possibilities for adapting to them. The most authoritative evaluations of climate change impacts are the national and international assessments that have been and are being carried out, for they bring together teams of experts that critically review and synthesize the findings of many individual investigators, and then put the resulting integrations of findings through extensive peer-review. For this reason, such assessment reports are featured in our compilation. To the extent practical, we also include references to other leading papers and resources, especially those studies that have been peer-reviewed and published or formed the basis for peer-reviewed assessments. You may notice that many resources appear multiple times in different locations. This is because many resources fit in more than one category and we hope that by listing a resource in all applicable locations, users will be more likely to find the resources they are looking for.

This website is a work in progress. We greatly appreciate suggestions of ways to improve the site as well as resources and citations that should be added to it.

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The work on Impacts of Climate Change has largely been done by three individuals: the project leader, Julian Dautremont-Smith, a recent graduate of Lewis and Clark College who is currently serving as a Truman Scholar and and will be starting a Fulbright fellowship in September; Nicole Okuniek, a German graduate student who did research on German language sites and German funded studies; and Sarah Ferriter, a student at University of Southern Maine, who researched climate change impact studies in parts of the former Soviet Union and air quality information worldwide. Sarah's work built on earlier air quality research done by Katherine Hoff of Haverford College, Edmund Brown of Sterling College.and Erica Duque of Dartmouth College.

The climate change impacts work built on previous work by Michael Ring of the Massachusetts Institute of Technology. Science Advisor for the climate change impacts work has been Dr. Michael MacCracken, an atmospheric scientist who recently retired from the University of California. Dr. MacCracken will head a scientific steering committee for the impacts of climate change effort. General guidance for the climate change impacts and air quality portions of climate.org has been provided by John Topping, Climate Institute President and Staff Director of US EPA's Office of Air and Radiation before he founded the Climate Institute in 1986.