National Climate Assessment Full Report (more...) (PDF 174 MB)
Highlights (more...) (PDF 116 MB)
Draft Report (more...)
Frequently Asked Questions (more...)
2012 State of the Climate Report (more...)
25x'25 Alliance Reports on Agriculture and Forestry in a Changing Climate (more...)
Reports of the US Climate Change Science Program (CCSP)
America's Climate Choices, US National Academies of Science (more...)
Climate Data Guide, National Center for Atmospheric Research (more...)
Climate Projections FAQ, US Department of Agriculture (more...)
Climate Engineering Fact Sheet, NOAA Research Council (more...)
The Easter Freeze of April 2007: A Climatological Perspective and Assessment of Impacts and Services (PDF 23.5MB)
Water, People, and the Future: Water Availability for Agriculture in the United States (PDF 8.6MB)
Position Statements on Climate Change by Scientific Societies
American Chemical Society (ACS) Position
Careful and comprehensive scientific assessments have clearly demonstrated that the
Earth's climate system is changing rapidly in response to growing atmospheric burdens
of greenhouse gases and absorbing aerosol particles (IPCC, 2007). There is very little
room for doubt that observed climate trends are due to human activities. The threats are
serious and action is urgently needed to mitigate the risks of climate change. The reality
of global warming, its current serious and potentially disastrous impacts on Earth
system properties, and the key role emissions from human activities play in driving
these phenomena have been recognized by earlier versions of this ACS policy statement
(ACS, 2004), by other major scientific societies, including the American Geophysical
Union (AGU, 2003), the American Meteorological Society (AMS, 2007) and the American
Association for the Advancement of Science (AAAS, 2007), and by the U. S. National
Academies and ten other leading national academies of science (NA, 2005). This
statement reviews key global climate change impacts and recommends actions
required to mitigate or adapt to currently anticipated consequences. More...
American Meteorological Society
The American Meteorological Society (AMS) http://www.ametsoc.org Council adopted a
new statement on climate change in August 2012.
The statement reads, in part,
"There is unequivocal evidence that Earth’s lower atmosphere, ocean, and land surface
are warming; sea level is rising; and snow cover, mountain glaciers, and Arctic sea ice
are shrinking. The dominant cause of the warming since the 1950s is human activities.
This scientific finding is based on a large and persuasive body of research. The
observed warming will be irreversible for many years into the future, and even larger
temperature increases will occur as greenhouse gases continue to accumulate in the
atmosphere. Avoiding this future warming will require a large and rapid reduction in
global greenhouse gas emissions. The ongoing warming will increase risks and
stresses to human societies, economies, ecosystems, and wildlife through the 21st
century and beyond, making it imperative that society respond to a changing climate. To
inform decisions on adaptation and mitigation, it is critical that we improve our
understanding of the global climate system and our ability to project future climate
through continued and improved monitoring and research. This is especially true for
smaller (seasonal and regional) scales and weather and climate extremes, and for
important hydroclimatic variables such as precipitation and water availability."
"Technological, economic, and policy choices in the near future will determine the extent
of future impacts of climate change. Science-based decisions are seldom made
in a context of absolute certainty. National and international policy discussions should
include consideration of the best ways to both adapt to and mitigate climate change.
Mitigation will reduce the amount of future climate change and the risk of impacts that
are potentially large and dangerous. At the same time, some continued climate change is
inevitable, and policy responses should include adaptation to climate change.
Prudence dictates extreme care in accounting for our relationship with the only planet
known to be capable of sustaining human life.."
Read the complete statement as follows:
Climate Change: An Information Statement of the American Meteorological Society
AGU revises position on climate change
Public release date: August 5, 2013
Contact: Peter Weiss
American Geophysical Union
WASHINGTON - The American Geophysical Union today released a revised version of its position
statement on climate change. Titled "Human-Induced Climate Change Requires Urgent Action," the statement
declares that "humanity is the major influence on the global climate change observed over the past 50 years"
and that "rapid societal responses can significantly lessen negative outcomes." AGU develops position
statements to provide scientific expertise on significant policy issues related to Earth and space science.
These statements are limited to positions that are within the range of available geophysical data or norms of
legitimate scientific debate.
AGU's position statements are renewed every 4 years. The climate change position statement was first
adopted in December 2003. It was then revised and reaffirmed in December 2007, and again in February 2012.
The full text of the revised statement is available online at