Reports show impacts of climate change are everywhere and increasing

Adaptation is needed, but greenhouse gases must be reduced to prevent the worst impacts

National Climate Assessment

The National Climate Assessment (NCA), prepared by the U.S. Global Change Research Program, uses the best available science to evaluate the impact of climate change in the United States.

The latest NCA concludes beyond a reasonable doubt that Americans are being affected by climate change.

The findings include:

  • Average U.S. temperatures have increased by 1.3 to 1.9 degrees Fahrenheit since record-keeping began in 1895. Most of this warming has occurred since 1970.
  • The most recent decade was America’s hottest on record.
  • The U.S. will likely see more warming in the next few decades – possibly up to another four degrees Fahrenheit in some areas.
  • The U.S. is seeing increasingly intense heat waves in the western portion of the country, and increasingly intense flooding in the eastern portion.
  • There has been an increase in the overall strength of hurricanes and in the number of strong hurricanes in the North Atlantic since the early 1980’s. The intensity of the strongest hurricanes is projected to continue increasing as the oceans continue to warm.
  • Climate change increases the likelihood of water shortages. The western U.S. relies heavily on mountain snowpack for water storage, and spring snowpack is declining in most of the West.

These changing conditions produce a variety of tangible stresses on society by affecting human health, water resources, agriculture, energy, infrastructure, and natural ecosystems. No corner of the country is immune to these changes.

IPCC 5th Assessment Report

The comprehensive IPCC 5th Assessment Working Group II and III reports focus on the worldwide impacts of climate change on people, species, and ecosystems; on our vulnerability to climate change, on adaptation, and on what and where mitigation is needed to avoid the worst impacts. The IPCC Working Group II report shows that climate change is impacting everything from energy demand to insect infestations. The IPCC Working Group III report shows that, more urgently than ever, the world must adopt strong mitigation efforts.

Infographics based on IPCC report findings

How is climate change currently impacting the world? Click the image below to find out [PDF].

How is climate change currently impacting the world?

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How will climate change continue to affect people across the United States? Click the image below to find out [PDF].

How will climate change continue to affect people across the United States?

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These reports, and all IPCC reports, are the result of work of hundreds of scientists worldwide who volunteered their time to synthesize climate change research from thousands of other scientists and experts, and have been approved by representatives from 195 nations.

How will climate change affect your area?

Explore the links below to read our summaries of the regional reports and find out what to expect in your area.

Media contact

  • Sharyn Stein
    (202) 572-3396 (office)