Climate Change FAQ

According to scientists and government organizations, including The U.S. Environmental Protection Agency, there is clear evidence that the Earth’s climate is warming:

  • Global surface temperatures have risen by 1.3 degrees Fahrenheit (ºF) over the last 100 years.
  • Worldwide, the last decade has been the warmest on record.
  • The rate of warming across the globe over the last 50 years (0.24ºF per decade) is almost double the rate of warming over the last 100 years (0.13ºF per decade).

The evidence of climate change extends well beyond increases in global surface temperatures. It also includes:

  • Changing precipitation patterns.
  • Melting ice in the Arctic.
  • Melting glaciers around the world.
  • Increasing ocean temperatures.
  • Rising sea level around the world.
  • Acidification of the oceans due to elevated carbon dioxide in the atmosphere.
  • Responses by plants and animals, such as shifting ranges.

Projections of Climate Change

At the current rate, the Earth’s global average temperature is projected to rise from 3 to 7°F by 2100, and it will get even warmer after that. As the climate continues to warm, more changes are expected to occur, and many effects will become more pronounced over time. For example, heat waves are expected to become more common, severe, and longer lasting. Some storms are likely to become stronger and more frequent, increasing the chances of flooding and damage in coastal communities.

Climate change will affect different regions, ecosystems, and sectors of the economy in many ways, depending not only on the sensitivity of those systems to climate change, but also on their ability to adapt to risks and changing conditions. Throughout history, societies and ecosystems alike have shown remarkable capacity to respond to risks and adapt to different climates and environmental changes. Today, effects of climate change have already been observed, and the rate of warming has increased in recent decades.

For this reason, human-caused climate change represents a serious challenge—one that could require new approaches and ways of thinking to ensure the continued health, welfare, and productivity of society and the natural environment.

For detailed information about greenhouse gas emissions, the effects of climate change, EPA efforts underway, and tips on what you can do, visit EPA’s Climate Change Web site at

The Environmental Protection Agency’s Fact Sheet on Climate Change:

Centers for Disease Control and Prevention (CDC). 2009. Climate change and public health: Heat waves.

Dai, A. 2010. Drought under global warming: A review. Wiley Interdisciplinary Reviews: Climate Change 2:45–65.

Environment Canada. 2010. Acid rain.–water/

Intergovernmental Panel on Climate Change (IPCC). 2007. Fourth assessment report:Climate change 2007. Cambridge, United Kingdom: Cambridge University Press.

National Academy of Sciences. 2010. Climate stabilization targets: Emissions, concentrations, and impacts over decades to millennia. Washington DC: The National Academies Press.

NOAA and IUCN—The World Conservation Union. 2006. A reef manager’s guide to coral bleaching. Great Barrier Reef Marine Park Authority.

NOAA. 2010. Coastal issues: Climate change.

U.S. Climate Change Science Program. 2009. Synthesis and assessment product 4.1: Coastal sensitivity to sea level rise: A focus on the mid–Atlantic region.

U.S. DOE and U.S. Environmental Protection Agency (U.S. EPA). n.d. Reduce climate change.

U.S. EPA. 2010. Climate change indicators in the United States. EPA 430–R–10–007.

U.S. EPA. 2011. Inventory of U.S. greenhouse gas emissions and sinks: 1990–2009.EPA 430–R–11–005.

U.S. Global Change Research Program. 2009. Global climate change impacts in the United States. T.R. Karl, J.M. Melillo, and T.C. Peterson (eds.). Cambridge University Press. Cambridge, United Kingdom.

World Health Organization. 2010. Climate change and health.