See Before-and-After Photos of the Changing Environment

Side-by-side comparisons reveal just how much glaciers, lakes, and snowpacks have been altered by nature and humans.

Published 6 Nov 2017, 16:28 GMT, Updated 5 Nov 2020, 06:04 GMT

From the ice sheets of Greenland to the deserts of Arizona, many of the world’s landscapes have been dramatically transformed as their climate grows warmer and drier. At the same time, water use and other human activities have altered many landscapes. NASA has accumulated striking photos that show just how much our surroundings have changed. Slide across each image to see before and after pictures.

A Shrinking Sea

The Aral Sea was once the fourth largest lake in the world. Progressively arid conditions and increased irrigation have decimated the lake and the surrounding communities that depend on it. Last year, the eastern basin dried completely.

Diminished Snowfall

Snowpack in California’s Sierra Nevada reached the lowest level in recorded history. In response to several years of drought, the state mandated water restrictions for the first time. California reservoirs depend heavily on annual snowmelt to meet its water demands.

Reservoir at Risk

Lake Mead, which depends on snowmelt from the Rockies, has seen its water levels plummet due to drought and increased demand. The lake’s elevation has dropped by 120 feet (36.57m), putting the Las Vegas Valley at risk because it depends on the reservoir for 90 percent of its water.

Glacier’s Retreat

Yosemite National Park’s Lyell Glacier has receded tremendously over the last century, exposing swaths of bedrock underneath. Because of their sensitivity to the environment, glaciers are vital barometers of climate change.

Choked by Drought

Decreased snowmelt from the Rockies severely reduced water levels in Arizona’s Lake Powell, affecting those who depend on it for water. Periodic droughts have become steadily more common. This year, the reservoirs were only at 45 percent capacity.

Breaking the Ice

The retreat of the Zachariæ Isstrøm glacier in Greenland has accelerated since 2012, dumping tons more ice into the Northern Atlantic every year. Experts fear the swift rate of the melting will have a tremendous impact on rising sea levels.

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