Drought, California

California is undergoing its most severe drought in decades, due in part to decreased rainfall and reduced winter snowpack in the Sierra Nevada mountain range as seen in these images. In 2013, California received less precipitation than in any other year since it became a state in 1850. Water conservation efforts are already in place for many locations and the potential for wildfire and major agricultural impact is high.

Shrinking ice cap, Iceland

More than half of Iceland’s numerous ice caps and glaciers lie near or directly over volcanoes. Seen here is Mýrdalsjökull, Iceland’s fourth largest ice cap, which covers the Katla volcano at the country’s southern tip. In the 2014 image, the depressions at the southwest-central part of Mýrdalsjökull are ice cauldrons caused by geothermal heat from below. Along the northern part of the ice cap, ablation has exposed brown bands of ash from past eruptions. But not all of the changes are associated with volcanic activity. Most of the monitored glaciers have been shrinking since the 1990s, including Sólheimajökull (lower left), which has been retreating as much as 50 meters (164 feet) per year. A parking lot near this glacier is moved almost annually to accommodate tourists.

Pine Island Glacier calving, Antarctica

An iceberg estimated to be 35 by 20 kilometers (22 by 12 miles) separated from Antarctica’s Pine Island Glacier between November 9 and 11, 2013. Such events happen about every five or six years but this iceberg, designated “B-31,” is about 50 percent larger than its predecessors in this area. A team of scientists from Sheffield and Southampton universities will track the 700 square-kilometer chunk of ice and try to predict its path using satellite data.

Ice melt, Ecuador

Atop the Cotopaxi Volcano — at 5,897 meters (19,347 feet), one of the tallest active volcanoes on Earth — sits the Cotopaxi Glacier. The glacier has considerable economic, social, and environmental importance. Its meltwaters provide fresh water and hydroelectric power to Ecuador’s capital city of Quito. But the glacier is melting and the rate has increased in recent years. The ice mass decreased 30 percent between 1956 and 1976 and another 38.5 percent between 1976 and 2006, a phenomenon tightly linked to global climate change. Comparing the 1986 and 2007 images reveals a notable reduction in the glacier at the volcano’s summit.

Petermann Glacier melt, Greenland

Petermann Glacier, Greenland. Left: June 26, 2010. Right: August 13, 2010. An iceberg more than four times the size of Manhattan broke off the Petermann Glacier (the curved, nearly vertical stripe stretching up from the bottom right of the images) along the northwestern coast of Greenland. Warmer water below the floating ice and at the sea’s surface were probably responsible for the break.

Ice melt, Tanzania

Mount Kilimanjaro in Africa. Left: February 17, 1993. Right: February 21, 2000. Kilimanjaro is the tallest freestanding mountain in the world and is made up of three volcanic cones. These before and after images show the dramatic decline in Kilimanjaro’s icecap over recent decades.

Ice melt, Italy / Switzerland

The nearly 15,000-ft-high Matterhorn mountain, located in the Alps on the border between Italy and Switzerland. Left: August 16, 1960 at 9.00 am. Right: August 18, 2005 at 9.10 am.