Andes Mountain Glaciers Melting at 'Unprecedented' Rate

It's getting hot in here, so someone please save the glaciers. The once mammoth ice formations in the Andes Mountains have melted at an unprecedented rate in the past three decades, losing more ice in that period then during any other time in the last 400 years, LiveScience.com reported.

The news arrives as part of a new review of research combining on-the-ground observations with aerial and satellite photos, historical records and dates from core ice samples extracted from glaciers. The retreat of glacial ice in the Andes is worse than the average glacier loss worldwide, researchers said in the report, which appeared in the journal The Cryosphere.

"Tropical Andes glaciers have lost on average between 30 to 50 percent (depending on the mountain ranges) of their surface since the late 70s," study researcher Antoine Rabatel, a scientist at the Laboratory for Glaciology and Environmental Geophysics in Grenoble, France, wrote in an email to LiveScience. 

South America's Andes Mountains, the longest continental mountain range in the world, hold 99 percent of the world's tropical glaciers: permanent bodies of ice at high enough altitudes to not be affected by the clement temperatures characteristic of the tropics. However, these types of glaciers are particularly vulnerable to climate change, because there is little change between temperatures during the seasons in the topics, Rabatel said.

"Glaciers of the tropical Andes react strongly and more rapidly than other glaciers on Earth to any changes in climate conditions," he said.

Andean glaciers hit their maximum sizes in the Little Ice Age, according to LiveScience, a cold period which lasted from around the 16^th to 19^th centuries. Glaciers in the outer tropics of Peru and Bolivia were at their largest in the 1600s, researchers found, with the highest Andean glaciers topping out around the 1730s, and lower-elevation glaciers peaking around the 1830s.

Glaciers have been gradually receding ever since, with one period of especially accelerated melt in the late 1800s, and another, far larger, accelerated melt period in the last 30 years.

The Andean glaciers have followed a pattern since the 1970s of accelerated melt with about two or three years in between of slower retreat and occasional ice growth. But despite some sporadic gains, in years when new ice was formed but then lost, the overall average has been permanently negative over the last half century, researchers wrote.

Glacial retreat isn't just a concern of environmentalists. The impending loss of the Andean glaciers is a serious problem for those people living in arid regions just west of the mountains, Rabatel said.

"The supply of water from high-altitude glacierized mountain chains is important for agricultural and domestic consumption, as well as for hydropower," he wrote.