glacier

Rivers are drying up

November 4, 2024 By EarthWise Leave a Comment

According to a new U.N. report, the world’s rivers had their driest year in at least three decades. Record heat and droughts in many places contributed to low levels of water in many of the world’s rivers.

The world faces problems of either too much or too little water. The warming climate has fueled both powerful storms with heavy rainfall and intense droughts around the globe.

Last year was the hottest year on record, and it’s a record that is unlikely to last long. The Mississippi River and Amazon River basins were at all-time lows. Major rivers with headwaters in the Himalayas – the Ganges, Brahmaputra, and Mekong Rivers – were all unusually dry.

According to the World Meteorological Organizations State of Global Water Resources Report, nearly half of the nearly 1,000 rivers tracked around the world had below-normal levels of water. Only 17% had above-average levels. Over the past 32 years, on average only a quarter of the rivers monitored had below-normal water levels and last-year’s 45% was the largest ever.

Last year’s severe heat shrank glaciers that are a crucial source of meltwater that feeds rivers. Glaciers lost more ice last year than they have in at least 50 years.

More than half of the world’s population lives within a couple of miles of a body of fresh water. The places with the highest population densities around the world are almost all near large rivers. Rivers provide freshwater for irrigation, consumption, and transportation and are an important source of energy. Historically, they have played an important role in the development of human society. The shrinking of rivers is a big deal.

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World’s Rivers Are Driest They Have Been in Decades

Photo, posted August 22, 2023, courtesy of Radek Kucharski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The doomsday glacier

October 9, 2024 By EarthWise Leave a Comment

The Thwaites Glacier is an enormous Antarctic Glacier. Its area is larger than that of Florida – in fact, larger than 30 other U.S. states – and it is melting. It has been retreating for 80 years but has accelerated its pace in the past 30. Its shedding of ice into the ocean already contributes 4% of global sea level rise. If it collapsed entirely, it would raise sea levels by more than 2 feet. For this reason, it has been dubbed the Doomsday Glacier.

A team of scientists has been studying it since 2018 in order to better understand what is happening within the glacier. They sent a torpedo-shaped robot to the glacier’s grounding line, which is the point at which the ice rises up from the seabed and starts to float. The underside of Thwaites is insulated by a thin layer of cold water. However, at the grounding line, tidal action is pumping warmer sea water at high pressure as far as six miles under the ice. This is disrupting the insulating layer and is speeding up the retreat of the glacier.

The potential collapse of the glacier is not even the only massive risk it poses. It also acts like a cork, holding back the vast Antarctic ice sheet. If that ice sheet were ever to collapse, sea levels could rise 10 feet.

A critical unanswered question is whether the ultimate collapse of Thwaites Glacier is already irreversible. There are regular heavy snowfalls that occur in the Antarctic which help replenish ice loss. Whether nations’ progress in slowing climate change can change the balance between ice accumulation and ice loss on the glacier remains to be seen.

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‘Doomsday’ glacier set to melt faster and swell seas as world heats up, say scientists

Photo, posted January 3, 2022, courtesy of Felton Davis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Oases and desertification

May 21, 2024 By EarthWise Leave a Comment

Oases are important sources of water for people, plants, and animals in the world’s desert areas. In fact, oases sustain 10% of the world’s population despite taking up only about 1.5% of land area. They form when groundwater flows and settles into low-lying areas or when surface meltwater flows down from nearby mountains and pools.

New research from the Chinese Academy of Sciences has found that oases added 85,000 square miles of new area from 1995 to 2020, mostly from artificial expansion projects, but over the same period lost 52,000 square miles from desertification and water scarcity. The net gain of 33,000 square miles is not considered to be sustainable given that it was mostly due to artificial causes. The oasis expansion projects were in Asia but losses due to desertification were also mostly in Asia.

Today, oases are found in 37 countries. Increases in oases mostly come from people intentionally converting desert land into oases using runoff water and groundwater pumping, creating grasslands and croplands. This mostly has taken place in China.

Human over-exploitation of dwindling groundwater can limit the sustainability of oases as can the long-term loss of glaciers.

The study highlighted ways to sustain healthy oases, including suggestions for improving water resource management, promoting sustainable land use and management, and encouraging water conservation and efficient water use. As the climate continues to change, these efforts will be increasingly important for a significant portion of the world’s population.

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World’s Oases Threatened By Desertification, Even As Humans Expand Them

Photo, posted August 3, 2008, courtesy of Paul Williams via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Glacier Loss Day | Earth Wise

October 9, 2023 By EarthWise Leave a Comment

Glaciers are sensitive indicators of climate change that respond to changes in both temperature and precipitation. But they are not only affected by climate change, they also affect climate change. As glaciers melt, they contribute to sea level rise, alter regional hydrology, and influence the global energy balance.

A group of glacier experts from the University of Innsbruck in Austria introduced a concept called “Glacier Loss Day” or GLD as a way to measure the annual mass balance of glaciers. Mass balance is the difference between the amount of snow and ice that accumulates on a glacier and the amount that melts or sublimates. If the mass balance is positive, the glacier is growing. If the mass balance is negative, the glacier is shrinking.

GLD is the day during the year when the glacier has lost all the mass it gained during previous winter. This is a similar concept to Earth Overshoot Day, which marks the date when humankind’s demand for ecological resources exceeds the amount the planet can regenerate during the year.

The Hintereisferner, a glacier in the Tyrolean Alps, has been monitored for more than 100 years and there are continuous records of its mass balance since 1952. In 2022, the GLD on the Hintereisferner was measured on the 23^rd of June. In the two previous years, it was reached in the middle of August. Even in years with large negative balances, such as 2003 and 2018, GLD did not occur until the end of July.

Every summer in the future may not be like 2022, but the trend is clear. Climate change is taking its toll on glaciers. Experts project that the Hintereisferner will lose half of its volume in the next 10 to 20 years.

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Glacier Loss Day indicates record breaking glacier melt

Photo, posted July 20, 2023, courtesy of Pedro Szekely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The World’s Hottest Day | Earth Wise

July 27, 2023 By EarthWise Leave a Comment

Early in July – for four days in a row – the average global temperature was the highest ever recorded. As many places around the world endured dangerous heatwaves, the average global temperature on the fourth of July reached 62.92 degrees Fahrenheit, the highest ever recorded by human-made instruments. On July 6th, the global temperature climbed even further to 63.01 degrees.

The average global temperature on an annual basis was about 56.7 degrees from the 1880s through the 1910s. Temperatures rose a bit after that but ended up about 57.2 degrees until the 1980s. After that, temperatures have risen fairly steadily as heat-trapping gases have accumulated in the atmosphere driving the current average above 58 degrees.

Global temperatures have only been directly measured since the mid-20th century. There are proxy measurements from sources like tree rings, ice core samples, glacier measurements, and more that indicate that the recent readings may be the warmest days the earth has seen in millennia.

Average global temperature is determined using temperature readings at thousands of locations on both land and sea across the entire planet. Those readings are compared with average temperatures at those locations for the date and the difference (known as the temperature anomaly) used to calculate a global average.

With the recent arrival of the El Niño in the Pacific Ocean, it is likely that the warming already being driven by greenhouse gas accumulation will intensify further.

In a summer already marked by extreme heatwaves in many locations, having the entire planet 4 or 5 degrees hotter than normal is a very big deal and most certainly not a record to celebrate.

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Earth reaches hottest day ever recorded 4 days in a row

Photo, posted October 29, 2008, courtesy of Darek via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Canada Lynx And Climate Change | Earth Wise

April 19, 2023 By EarthWise Leave a Comment

Canada lynx are medium-sized North American big cats known for their long, black ear tufts, and their ability to hunt across the surface of deep snow. Historically, the predator’s habitat ranged across Alaska, Canada, and much of the Northern United States. But in the contiguous U.S. today, the Canada lynx exists only in several disjunct populations in Maine, Minnesota, Colorado, Idaho, Washington and Montana.

While Glacier National Park in Montana is famous for its grizzly bears and mountain goats, the park also holds a surprising number of Canada lynx, and could serve as a much-needed climate refuge for the big cats in the future.

Glacier National Park is one of the few, large, protected areas located within the Canada lynx range in the Lower 48. Using an array of 300 motion-sensitive cameras on hiking trails throughout Glacier, researchers from Washington State University conducted the first parkwide occupancy survey for Canada lynx inside the park. They were surprised to find that Glacier is home to roughly 50 Canada Lynx. In fact, the researchers found that the iconic predator resides across most of the park’s 1,600 square-mile landscape, although at lower densities than in the core of its range further north.

The researchers also found that Canada lynx are distributed at lower elevations inside Glacier. Since the cats are a cold-adapted species that need the deep snow, within Glacier, they have a lot of room to climb in elevation as the climate warms.

The researchers hope their survey can serve as a baseline population estimate to help their collaborators with the National Park Service keep tabs on the numbers of Canada lynx in Glacier.

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Glacier National Park could be climate haven for Canada lynx

Photo, posted February 22, 2014, courtesy of Eric Kilby via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Climate Change On Mount Everest | Earth Wise

March 21, 2022 By EarthWise Leave a Comment

Climate change has shown up in the highest place on Earth. The highest glacier on Mount Everest is rapidly retreating with rising temperatures.

New research by an international team led by the University of Maine and published in the journal Climate and Atmospheric Science has determined that the South Col Glacier atop Mount Everest has shrunk by half since the 1990s. Its ice mass has thinned by an estimated 180 feet.

The glacier used to be covered by snow, which reflected the sun’s light and insulated the mass of ice under the snow. But warmer temperatures, lower humidity, and more severe winds have eliminated the snow cover, fueling the decline of the glacier.

The study of the South Col Glacier highlights the critical balance created by snow-covered surfaces and exposes the potential for loss throughout high mountain glacier systems as snow cover is depleted by warming temperatures. When even the highest glacier on Mount Everest is impacted, it is clear that no place is safe from the warming climate.

The human significance of this development is substantial. More than 200 million people in Asia depend on meltwater from glaciers in the high mountains of the continent for their freshwater needs. But now glaciers in the mountains are melting faster than they can be replenished by snowfall.

As for Mount Everest itself, future expeditions on the mountain will face new challenges as glacier melting causes more avalanches and climbers accustomed to digging into ice and snow will need to scale more exposed bedrock. Climate predictions for the Himalaya in general all anticipate continued warming and continued loss of glacier mass.

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Climate Change Has Reached the Top of Mount Everest, Thinning Its Highest Glacier

Photo, posted October 27, 2011, courtesy of Goran Hogland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Threat From Thwaites | Earth Wise

January 20, 2022 By EarthWise Leave a Comment

The Thwaites Glacier in Antarctica is the widest glacier in the world. It is about 80 miles across and in places extends to a depth of about 2,600 to 3,900 feet. The glacier is roughly the size of Florida, and it currently contributes 4% of annual global sea level rise as it continues to retreat from a warming ocean.

The International Thwaites Glacier Collaboration is a team of nearly 100 scientists dedicated to studying the glacier. According to the scientists, Thwaites has doubled its outflow speed within the last 30 years. The glacier in its entirety holds enough water to raise global sea levels by over two feet, which would be catastrophic.

A third of the glacier flows more slowly than the rest because it is braced by a floating ice shelf that is held in place by an underwater mountain. The concern is that the brace of ice slowing the glacier may not last for long.

Beneath the surface, warmer ocean water is attacking the glacier from all angles. The water is melting the ice directly beneath the glacier causing it to lose its grip on the underwater mountain. Massive fractures have formed and are growing.

Warm water is also a threat for what is called the grounding zone, which is the area where the glacier lifts off the seabed. There are many possible scenarios under which there could be a major ice loss from the glacier. It is unclear how quickly it could occur. It might take decades, or it could be centuries. The threat is large enough and real enough that continued observation and research is essential.

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The Threat from Thwaites: The Retreat of Antarctica’s Riskiest Glacier

Photo, posted October 16, 2012, courtesy of J. Yungel / NASA Ice via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bad News For The Aletsch Glacier

November 5, 2019 By EarthWise Leave a Comment

The Aletsch Glacier in Switzerland is the largest glacier in the Alps. Every year, it attracts thousands of visitors from around the world. The huge ice flow in the Upper Valais region of Switzerland is an Alpine tourist attraction second only to the Matterhorn. In the summer, meltwater from the glacier is an important water source in the dry Rhone Valley.

As the climate continues to warm, the massive glacier continues to shrink. The tongue of the glacier has receded by about a kilometer since the year 2000 and scientists predict that this trend will continue over the coming years.

Detailed simulations by researchers at ETH Zurich assessed the future of the Aletsch Glacier under different scenarios related to the concentration of CO2 in the atmosphere and the resulting warming.

The best-case scenario in which global warming is limited to less than 2 degrees Celsius would result in the glacier being half the size it is today by the end of the century. If the global community does not pull together quickly to take effective measures against global warming, Switzerland could warm by as much as 4 to 8 degrees and by 2100, what was once the largest glacier in the Alps will be a couple of measly patches of ice.

To understand how much global warming has already impacted the glacier to date, even if somehow the climate remains the same as it has been for the past 10 years going forward, the ice volume of the Aletsch glacier will still decrease by nearly half its volume by the end of the century. The glacier is no longer in equilibrium with the climate.

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