Community Connections

Although the American Southwest has low annual rainfall and seasonally high temperatures, this region supports a vast array of plants and animals, as well as millions of people. Since water is so scarce in the Southwest, every drop is precious. Even a small increase in temperature or a decrease in precipitation in this already arid region can seriously threaten natural systems and society.

Droughts reduce the amount of water available for generating electricity and contribute to increased pest outbreaks and wildfires that damage local economies. 

Parts of the Southwest are also experiencing long-term reductions in mountain snowpack, which accounts for a large portion of the region’s water supply.

This feature focuses on six states that are commonly associated with the American Southwest and that are characterized by arid landscapes and scarce water supplies: Arizona, California, Colorado, Nevada, New Mexico, and Utah. 

Regions in the far north are warming more quickly than other parts of the world, and this pattern is expected to continue. The Tanana, Yukon, and Kuskokwim rivers in Alaska provide a noteworthy record of northern climate. For more than a century, local citizens have recorded the date when the ice on these rivers starts to move or break up each spring.

Since 1917, the Nenana Ice Classic competition on the Tanana River has held a contest to guess the exact date and time of day when the river ice will break up. Similar long-standing traditions exist in Dawson City on the Yukon River just across the border in Canada, and in Bethel for the Kuskokwim River. The data collected by these communities highlights how the river ice breakup dates in Nenana, Dawson City, and Bethel have changed over time.

River ice breakup is more than just a friendly competition, though. Ice breakup represents an important time of transition for communities that rely on these rivers for transportation, subsistence hunting and fishing, and other needs. Early thawing can lead to severe ice movement, jamming, damage to infrastructure, and destructive floods.

Sebago Lake is one of the jewels of the 'Lakes Region' in Maine. It is the deepest and 2nd largest lake in the state. The lake, lined with summer camps, is the primary water supply for the city of Portland and provides anglers with top-notch fishing including the famed native, land-locked salmon. Each year Sebago Lake is headquarters for a  regional ice fishing derby  (external link).

The formation of ice cover on lakes in the winter and its disappearance the following spring depends on climate factors such as air temperature, cloud cover, and wind. Conditions such as heavy rains or snowmelt in locations upstream or elsewhere in the watershed also affect the length of time a lake is frozen.  Thus, ice formation and breakup dates are key indicators of climate change.

Changes in ice cover can affect the physical, chemical, and biological characteristics of a body of water. These changes, in turn, can affect plant and animal life cycles and the availability of suitable habitat.

The timing and duration of ice cover on lakes and other bodies of water can also affect society—particularly in relation to shipping and transportation, hydroelectric power generation, and recreation such as ice fishing.

Washington, D.C. has enjoyed cherry blossoms each year dating back to 1912, when Japan gave about 3,000 cherry trees to the United States as a gift of friendship. These trees bring more than 1.5 million visitors to the area every year during the National Cherry Blossom Festival. Not surprisingly, the festival is planned to coincide with the peak bloom of the cherry trees.

Scientists have very high confidence that recent warming trends in global climate are causing spring events such as leaf growth and flower blooms to happen earlier. In the case of Washington’s cherry blossoms, earlier bloom dates could affect tourism and the local economy.

As sea level rises, dry land can turn into wetland or open water. Existing wetlands including salt marshes, mangrove forests, and other coastal wetlands are at risk of being converted to open water.

Nearly 10 million Americans live in a coastal floodplain. Coastal ecosystems are also at risk, as coastal wetlands provide valuable nursing, feeding, breeding, and resting areas for fish, shellfish, mammals, and birds. These wetlands provide valuable ecosystem services such as food production and recreation and serve as buffers against storm and wave damage.

The Atlantic coast is particularly vulnerable because of its low elevations and sinking shorelines. This feature examines the amount of land lost to sea level rise along the Atlantic coast from Florida to New York, based on satellite data that have been collected and analyzed at five-year intervals since 1996.

The coastal land cover data are routinely compiled by the National Oceanic and Atmospheric Administration’s Coastal Change Analysis Program, and they represent the federal government’s most comprehensive set of data on land use and land cover in the coastal zone.

Established in 1910, Glacier National Park in Montana is one of the most visited national parks in the United States. However, warming temperatures are melting the park’s alpine glaciers, which has implications not only for tourism, but also for the ecosystems, animals, and people that depend on glacier-fed streamflow. 

In 2017, the U.S. Geological Survey (USGS) published a study where they analyzed aerial images from 1966, 1998, 2005, and 2015 to assess changes over time in the surface area of Glacier National Park’s 37 named glaciers. Scientists are studying the Park’s alpine glaciers to better understand what these changes mean for the local environment and park management decisions.    

For at least 50 years, a colony of black guillemots have made Cooper Island near Utqiagvik (formerly Barrow), Alaska, home. The area provides an ideal habitat for these birds, as black guillemots spend the winter on Arctic sea ice and breed on land near the edge of the ice in summer.

The region has experienced an increase in the number of days without snow cover each year. Although this longer period ensures snow-free nest cavities during breeding season, sea ice has also started to melt earlier and freeze later.

This ecosystem change has implications not only for black guillemots, but also for other animals in the Arctic, such as polar bears, and for people who depend on Arctic animals for food and other resources.

In the Pacific Northwest, warming river and stream temperatures will threaten ecosystems and species, including salmon populations that play an important role in the diet, culture, religion, and economy of tribes in this region. 

Salmon are sensitive to water temperature at many stages of their lives. Salmon need cold water to migrate and for their young to hatch and grow successfully. River and stream temperatures in the Pacific Northwest are influenced by many factors, but are expected to rise as average air temperatures increase.