sahara desert

Glacial Loss In The Swiss Alps | Earth Wise

December 14, 2022 By EarthWise Leave a Comment

In 2022, glaciers in the Swiss Alps melted more than in any year on record. This is the latest piece of bad news for the country’s glaciers, which have lost more than half of their volume of ice since the 1930s.

The melting season for Switzerland’s snow and ice typically starts in May and ends in early October. This year’s melting season caused glaciers in the Diablerets mountain group to thin by an average of 13 feet, which is 3 times the amount of thinning observed over the past decade. The Tsanfleuron pass between two of the glaciers is now exposed as bare rock for the first time in several thousand years. Across Switzerland, glaciers lost about 6% of their remaining volume just this year. The previous worst year for glaciers was 2003, when losses were nearly 4%.

There was significant melting this year in part because of the small amount of snowfall over the winter. That snow melted quickly, being sped up by the warming effect of dust from the Sahara Desert falling on the snow. By early summer, there was no longer a protective blanket of snow on the glaciers, exposing them to summer heat.

The loss of glaciers is far more serious than the disappearance of aesthetically pleasing landscape features. Glaciers act as reservoirs of water that persist through the summer months. Melt from glaciers provides water to ecosystems and creates habitats for plants and animals. Cold runoff from glaciers affects downstream water temperatures which have a major impact on insects, fish, and other creatures. Globally, melting glaciers contribute more than 20% of the observed ongoing sea-level rise.

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Rocky Road for Swiss Glaciers

Photo, posted June 22, 2015, courtesy of Dennis Jarvis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

River Of Dust | Earth Wise

April 25, 2022 By EarthWise Leave a Comment

Every year, more than 100 million tons of dust blow out of North Africa. Strong seasonal winds lift the dust from the Sahara Desert northward. A few times a year, the winds from the south are strong and persistent enough to drive the dust all the way to Europe.

On March 15, a large plume of Saharan dust blew out of North Africa and crossed the Mediterranean into Western Europe. European cities were blanketed with the dust, degrading their air quality, and turning skies orange. Alpine ski slopes were stained with the dust.

These dust events are associated with so-called atmospheric rivers that arise from storms. Such rivers usually bring extreme moisture but can also carry dust. Over the past 40 years, nearly 80% of atmospheric rivers over northwestern Africa have led to extreme dust events over Europe. The March 15 event was associated with Storm Celia, a powerful system that brought strong winds, rain, sleet, hail, and snow to the Canary Islands.

Atmospheric dust plays a major role in climate and biological systems. The dust absorbs and reflects solar energy and also fertilizes ocean ecosystems with iron and other minerals.

The climate effects of dust are complicated. Dust can decrease the amount of sunlight reaching the surface, affect cloud formation, and decrease temperatures. But dust also darkens the snowpack, leading to more rapid snowmelt. A 2021 dust event resulted in a rapid melt of Alpine snow, reducing its depth by half in less than a month.

The effects of this year’s dust event are not yet known, but this atmospheric river associated with Storm Celia appeared to carry less water and more dust compared with the 2021 event.

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An Atmospheric River of Dust

Photo, posted December 2, 2019, courtesy of Catherine Poh Huay Tan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Living In Extreme Heat | Earth Wise

June 3, 2020 By EarthWise Leave a Comment

Global climate change has already left observable effects on the planet. Glaciers have shrunk, trees are flowering sooner, plant and animal ranges have shifted, and so on. Many effects of climate change that scientists had predicted in the past are now occurring. The loss of sea ice, intensifying heat waves, and accelerating sea level rise are some examples.

According to a new study recently published in the journal Proceedings of the National Academy of Sciences, climate change is going to affect humans earlier, harder, and more widely than previously projected. The research team found that one billion people will be either displaced or endure insufferable heat for every one degree Celsius rise in global temperatures.

Under a worst case climate scenario, land that one third of the world’s population currently calls home will be as hot as the hottest parts of the Sahara desert within 50 years. Even under a more optimistic climate outlook, 1.2 billion people will still be exposed to temperatures outside the climate niche in which humans have thrived for at least 6,000 years.

The majority of the human population has always lived in regions where the average annual temperatures were between 43 degrees Fahrenheit and 82 degrees Fahrenheit. These are ideal temperatures for human health and for food production. But this temperature range is shrinking and shifting as a result of climate change.

The study’s authors predict there will be more change in the next 50 years than there has been in the past 6,000 years. They hope their findings will convince policymakers to accelerate their plans for emissions reductions and other climate mitigation strategies.

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Future of the human climate niche

One billion people will live in insufferable heat within 50 years – study

Photo, posted November 22, 2008, courtesy of Ronnie Finger via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Record European Heatwave

August 1, 2019 By EarthWise Leave a Comment

Sahara Desert winds blasted Europe in June, especially during a five-day heatwave that set many records. Between that and weather elsewhere, June was not only one of the hottest ever for that continent, but also for the world as a whole.

In Europe, the average temperature was about 5 degrees Fahrenheit above the June average of a century ago. The global temperature was nearly 2 degrees Fahrenheit higher.

The European heatwave broke temperature records in France, Switzerland, Austria, Germany, and Spain. A temperature above 114 degrees was recorded near the French city of Nîmes.

The intense heat lead to wildfires in Spain and Germany, and widespread disruption across Europe. Undoubtedly, the heatwave has caused many premature deaths, but it will take some time to compile those statistics. The European heatwave of 2003 caused more than 70,000 premature deaths.

According to calculations by climate scientists, the record-breaking heatwave in June was made at least 5 and as much as 100 times more likely by climate change. Global heating caused by the carbon emissions from burning fossil fuels and other human activities means that heatwaves are becoming more probable and severe. So-called attribution studies estimate how much more likely and severe such events are.

The researchers used temperature records stretching back to 1901 to assess the probability of a heatwave last month and in the past. They also examined climate change models to assess the impact of global heating. More than 230 attribution studies to date around the world have found that 95% of heatwaves were made more likely or worse by climate change.

It was the hottest June on record in Europe by a country mile and there are likely to be more months like it in the future.

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Climate Change Made Last Month’s European Heatwave At Least Five Times More Likely

Photo, posted February 13, 2018, courtesy of Guilhem Vellut via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Shifting Climate Zones

November 16, 2018 By EarthWise Leave a Comment

As the climate warms, the planet’s landscape is changing. The Arctic ice is shrinking, the ocean is rising altering coastlines, and plants, animals and diseases are on the move. The world’s climate zones are changing in significant and measurable ways.

The Sahara Desert Is Expanding

May 15, 2018 By EarthWise Leave a Comment

Deserts are barren areas of land where little precipitation occurs, resulting in living conditions that are hostile for plant and animal life. These regions are typically defined by low average annual rainfall—usually 100 millimeters (less than 4 inches) of rain per year or less.

Sahara Greening And Tropical Cyclones

July 25, 2017 By EarthWise

Global weather patterns are influenced by environmental conditions in places around the world. One of the world’s major weather creators is the Sahara Desert. The Sahara is the largest hot desert in the world. The only larger deserts of any sort are in the polar extremes of the planet and are thus not hot deserts at all.

Did People Create The Sahara Desert?

April 25, 2017 By EarthWise

One of the arguments some people make when discussing human causes of climate change is that people can’t cause such massive changes. However, there is a long historical record of human-driven ecological and climatic change in Europe, North America and New Zealand, among other places.

The World’s Largest Solar Plant

March 16, 2016 By WAMC WEB

Morocco has switched on what is going to be the world’s largest concentrating solar power plant. The plant is located near the city of Ouarzazate, an area previously famous as a filming location for blockbusters like Lawrence of Arabia and Gladiator. When fully online in 2018, the plant will produce enough energy to power over a million homes. It will also cut carbon emissions by 760,000 tons a year.