mountain range

Glaciers in Venezuela

June 24, 2024 By EarthWise Leave a Comment

There are nearly 200,000 glaciers in the world. About 91% of them are in Antarctica and 8% in Greenland. The rest are scattered across nearly 50 countries. The non-polar country with the most glaciers is actually Pakistan, which has over 7,200 of them. But as the world continues to warm, glaciers are shrinking back, and many are disappearing altogether.

Venezuela, once home to six glaciers, has become the first country in the Americas to lose all of its glaciers. Slovenia is considered to be the first country to lose its glaciers in modern times, perhaps as long as 30 years ago. Glacial thawing has been worsening over the past decade throughout the Andes, which cover parts of Colombia, Venezuela, Bolivia, Ecuador, Peru, Chile, and Argentina.

Five of Venezuela’s glaciers had largely melted away by 2011. The Humboldt glacier, which is on the highest peak in the Cordillera de Mérida mountain range in Venezuela, has now been declared as too small to be classified as a glacier. It once covered over a thousand acres; it now has less than 5 acres of ice. The US Geological Survey defines glaciers as ice bodies extending 25 acres or more.

The loss of glaciers in the Andes has serious consequences for communities that live on their slopes and depend upon glacial melt for water and for energy and food production.

At least 80% of glaciers worldwide are on track to mostly disappear by the year 2100 because of global warming. Given that previous forecasts estimated that the Humboldt glacier might last another decade, the prospects for the world’s remaining glaciers are not good.

**********

Web Links

Venezuela becomes first nation in the Americas to lose all glaciers

Photo, posted November 11, 2012, courtesy of Tim Snell via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Death Valley Flooding | Earth Wise

September 13, 2022 By EarthWise Leave a Comment

Furnace Creek in Death Valley is the driest place in North America. Its average annual rainfall is under two inches. On August 5th, a thousand-year rainfall event dropped 1.46 inches of rain – about three-quarters of a year’s precipitation. The all-time record for a single day is 1.47 inches, set in April 1988. The storm did break the record for the most rain ever recorded in August, which averages just over a tenth of an inch of rain for the entire month.

The flash flood washed debris over roads, swept away and buried cars, knocked a water facility offline, damaged buildings, and stranded about a thousand visitors and staff in Death Valley National Park. By the next day, the flood water had mostly receded, and stranded visitors could be escorted out of the park by National Park personnel.

Death Valley sits at 282 feet below sea level. If it were not for the extremely arid climate there, Death Valley would likely be filled with water. However, humid air masses traveling east from the Pacific Ocean have to cross four mountain ranges before they reach the desert valley. Those air masses lose their moisture in the form of rain on the western slopes of the mountain, leaving a dry area, or rain shadow, on the eastern sides. By the time the air masses reach Death Valley, they are bone dry. On rare occasions, the lowest spot in the valley fills with water forming a wide, shallow lake, known as Lake Badwater.

The extreme heat and aridity of Death Valley evaporates the temporary lake quickly, returning the valley to its usual state. Furnace Creek still holds the record for the highest air temperature ever recorded: 134 degrees Fahrenheit.

**********

Web Links

Death Valley Flash Flooding

Photo, posted April 7, 2021, courtesy of Matthew Dillon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

California Trees Are Dying | Earth Wise

August 19, 2022 By EarthWise Leave a Comment

California relies on extensive forests to help reduce the amount of carbon dioxide entering the atmosphere. But extensive drought and increasingly frequent wildfires have been reducing the state’s tree population for the past three decades.

A comprehensive study by a team of scientists from the University of California Irvine used satellite data to study vegetation changes between 1985 and 2021. Across the entire state, tree cover area has declined 6.7% over that time period. The results varied from region to region across the state.

Southern California exhibited the sharpest decline, where 14% of the tree population in local mountain ranges vanished, potentially permanently. In the Sierra Nevada mountains, tree populations were relatively stable until about 2010. After that, a severe drought followed by historically large wildfires resulted in a 8.8% die-off of trees. The northern parts of the state, with higher rainfall and cooler temperatures, fared better, being able to more easily recover from wildfires.

The study goes beyond measuring the tree population of the state and its effects on carbon storage. The data is also important for understanding how changes in forest cover affects water resources and fire behavior in the state.

The decline of trees in California is affecting the carbon storage abilities of the state. The satellite survey showed that as the tree populations have dropped, the state’s coverage of shrubs and grasses has risen, possibly indicating that permanent ecosystem shifts are occurring. The forces contributing to the decline of trees in California are not going away any time soon. As a result, the threat to California’s ability to mitigate the effects of climate change continues to grow.

**********

Web Links

UCI study: California’s trees are dying, and might not be coming back

Photo, posted March 24, 2016, courtesy of David Fulmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.