This web page will introduce and lead you through the content of the most comprehensive and authoritative report of its kind. The report summarizes the science and the impacts of climate change on the United States, now and in the future. It focuses on climate change impacts in different regions of the U.S. and on various aspects of society and the economy such as energy, water, agriculture, and health. It’s also a report written in plain language, with the goal of better informing public and private decision making at all levels.
In addition to discussing the impacts of climate change in the U.S., the report also highlights the choices we face in response to human-induced climate change. It is clear that impacts in the United States are already occurring and are projected to increase in the future, particularly if the concentration of heat-trapping greenhouse gases in the atmosphere continues to rise. So, choices about how we manage greenhouse gas emissions will have far-reaching consequences for climate change impacts. Similarly, there are choices to be made about adaptation strategies that can help to reduce or avoid some of the undesirable impacts of climate change. This report provides many of the scientific underpinnings for effective decisions to be made – at the national and at the regional level.
Use the menu navigation to access the various sections of the report. You can also download the corresponding PDFs or order hard copies of the report from Cambridge University Press.

Some Key findings include:

• Climate changes are underway in the United States and are projected to grow. Climate-related changes are already observed in the United States and its coastal waters. These include increases in heavy downpours, rising temperature and sea level, rapidly retreating glaciers, thawing permafrost, lengthening growing seasons, lengthening ice-free seasons in the ocean and on lakes and rivers, earlier snowmelt, and alterations in river flows. These changes are projected to grow.
• Crop and livestock production will be increasingly challenged. Agriculture is considered one of the sectors most adaptable to changes in climate. However, increased heat, pests, water stress, diseases, and weather extremes will pose adaptation challenges for crop and livestock production.
• Threats to human health will increase. Health impacts of climate change are related to heat stress, waterborne diseases, poor air quality, extreme weather events, and diseases transmitted by insects and rodents. Robust public health infrastructure can reduce the potential for negative impacts.