Extreme Events

Excerpt from the Southwest Climate Change Network, written by Zack Guido, University of Arizona

Extreme events, such as floods, heat waves, and hurricanes, are rare weather occurrences that often cause the greatest damage to society. In the yearly distribution of rainfall, for example, extreme precipitation events that cause flooding occur less frequently than the “average” rainfall events, but the economic toll of floods is many times greater.

Any climate variable can be characterized by a probability distribution, which conveys …

Enhanced Greenhouse Gas Effect

Excerpt from the Southwest Climate Change Network, written by Zack Guido, University of Arizona

Greenhouse gases (GHGs) such as carbon dioxide, methane, and water vapor, are naturally part of the Earth’s atmosphere. These gases tap heat from the sun’s radiation in the atmosphere and act as powerful amplifiers of temperature. The natural greenhouse gas effect (Figure 1) helps to elevate the average temperature in the lower atmosphere to a comfortable 60 degrees F. Without GHGs, average atmosphere temperatures would …

Climate Control Feedbacks

Excerpt from the Southwest Climate Change Network, written by Zack Guido, University of Arizona

There are many feedback mechanisms in the climate system that moderate the magnitude of climate change. Positive feedbacks incite continued change, while negative feedbacks halt change. With respect to temperature, positive feedbacks tend to amplify warming, while negative feedbacks suppress it. Figure 1 illustrates two important feedback loops that moderate the climate. These feedbacks contribute to uncertainties in future climate change and make pinpointing the …

Climate Change Impacts in the Northeastern U.S.

Adapted from: T.R. Karl, J.M. Mellilo, and T.C. Peterson (eds.). Global Climate Impacts in the United States. Cambridge University Press, 2009. Available online at USGCRP
The region of the United States that is covered by report on Regional Impacts from the U.S. Global Climate Research Program.

 

 

 

 

Climate change in the Northeast has meant hotter temperatures, more heavy rains, and less lake ice and snow cover. Northeast annual average temperature has increased by 2 degrees Fahrenheit since 1970, with winter temperatures rising twice this much. The warming has resulted in more frequent unusually hot days and a longer growing season. The region …

Climate Change Impacts in the Great Plains

Adapted from: Global Climate Impacts in the United States. T.R. Karl, J.M. Mellilo, and T.C. Peterson (eds.). Cambridge University Press, 2009. Available online at USGCRP
The region of the United States that is covered by the Regional Impacts report for the Great Plains from the U.S. Global Climate Research Program.


Over the last few decades, average temperatures have risen throughout the Great Plains, with the largest increases occurring in the winter months and over the northern states. Relatively cold days are becoming less frequent and relatively hot days more frequent.

In the future, temperatures are projected to continue to increase with larger changes under scenarios …

Climate Change Impacts in the Southeastern U.S.

Adapted from:Global Climate Impacts in the United States. T.R. Karl, J.M. Mellilo, and T.C. Peterson (eds.). Cambridge University Press, 2009. Available online at USGCRP
The region of the United States that is covered by report on Regional Impacts for the Southeastern United States from the U.S. Global Climate Research Program.

 

 

The Southeast region serves as an example of how rising temperatures can be associated with both increased drought and an increased frequency of downpours and other intense precipitation events. Southeast annual average temperature has risen 2 degrees Fahrenheit since 1970, with the greatest seasonal increase in the winter months. From 1901 to 2008, there was …

Climate Change Impacts in the Northwestern U.S.

Adapted from: Global Climate Impacts in the United States. T.R. Karl, J.M. Mellilo, and T.C. Peterson (eds.). Cambridge University Press, 2009. Available online at USGCRP Regional Climate Change Impacts
The region of the United States that is covered by report on Regional Impacts for the Northwestern United States from the U.S. Global Climate Research Program.


Warming in the Northwest has varied by location, and the ongoing temperature rise brings more risk of wildfire, challenges to native species, increased erosion, and potential water challenges. Annual average temperature over the Northwest region rose about 1.5 degrees Fahrenheit over the past century, with some areas experiencing increases up to …

Climate Change Impacts in the Pacific Islands and the Caribbean

Adapted from: Global Climate Impacts in the United States. T.R. Karl, J.M. Mellilo, and T.C. Peterson (eds.). Cambridge University Press, 2009. Available online at USGCRP Regional Climate Change Impacts
The region of the United States that is covered by report on Regional Impacts for the Pacific Islands by the U.S. Global Climate Research Program.


Climate change presents unique challenges to U.S.-affiliated islands, which include Hawaii, Guam, and Puerto Rico. Small islands are vulnerable to sea-level rise, coastal erosion, extreme weather events, coral reef bleaching, ocean acidification, and contamination of freshwater resources with saltwater. The islands have experienced rising temperatures and sea level in recent decades. …

Climate Change Impacts in the Southwestern U.S.

Adapted from: Global Climate Impacts in the United States. T.R. Karl, J.M. Mellilo, and T.C. Peterson (eds.). Cambridge University Press, 2009. Available online at USGCRP Regional Climate Change Impacts
The region of the United States that is covered by report on Regional Impacts for the Southwestern United States from the U.S. Global Climate Research Program.


Recent warming in the Southwest has been among the most rapid in the nation, and it raises concerns about the region’s water sustainability. The warming is associated with declines in spring snowpack and Colorado River flow. Water supplies in some areas are already becoming limited. Conflict over water rights is likely …

Climate Change Impacts in the Midwestern U.S.

Adapted from: Global Climate Impacts in the United States. T.R. Karl, J.M. Mellilo, and T.C. Peterson (eds.). Cambridge University Press, 2009. Available online at USGCRP
The region of the United States that is covered by the Regional Impacts report for the Midwest from the U.S. Global Climate Research Program.


In the Midwest, precipitation has increased along with temperature in recent decades. Average temperatures in the Midwest have risen, with the largest increases in winter. The length of the frost-free or growing season has been extended by one week, mainly due to earlier dates for the last spring frost. Since the 1980s, large heat waves …