Earth Wise

A look at our changing environment.

You are here: Home / Archives for desert

desert

Lithium Mining And The Environment | Earth Wise

By Leave a Comment

The Salar de Atacama in Chile is a large, dry salt flat surrounded by mountain ranges and is one of the driest places on Earth. Parts of the Atacama Desert have gone without rain for as long as people have been keeping track. Water rich in dissolved salts lies beneath this flat surface and it is particularly rich in lithium salts.  Forty percent of the world’s known lithium deposits are the in the Salar.

Lithium is the key component of the batteries that power electric cars as well as cell phones and computers.  It is an essential part of the transition away from fossil fuels and towards green energy.  But it is important that this element is obtained responsibly with minimal damage to the environment.

Lithium, the lightest of the metals, tends to occur in layers of volcanic ash, but reacts quickly with water.  It leaches into groundwater and settles in flat basins where it remains in a briny solution.  This dense brine often ends up beneath pockets of fresh surface water, which are havens for fragile ecosystems.

A new study by the University of Massachusetts Amherst looked at the hydrological impact of lithium mining in the Salar.  The study found that the impact of lithium mining depends critically on how long surface water is in place.  Much of the fresh water there is at least 60 years old.  Both droughts and extreme rainfall can cause major changes to the surface water that ordinarily comes from mountain runoff.  Lithium mining itself only accounts for less than 10% of freshwater usage in the Salar. But the state of the surface water needs to be carefully monitored to protect the ecosystems as the climate continues to change.

**********

Web Links

How environmentally responsible is lithium brine mining? It depends on how old the water is

Photo, posted February 21, 2016, courtesy of Jorge Pacheco via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The All-Time Hottest Day | Earth Wise

By Leave a Comment

Last year saw record high temperatures in many places around the world and this year started out with more of the same.  In mid-January, Onslow, a small town in Western Australia, measured a high temperature of 123.3 degrees, tying the all-time highest temperature ever recorded anywhere in the Southern Hemisphere.  The previous reading was also made in Australia back in 1960.

The new temperature record was set just as climate institutions around the world were announcing that the past seven years have been the highest in recorded history.

The list of temperature records set in 2020 and 2021 is a long one.   2020 was the hottest year in recorded history.  July 2021 was the hottest month ever recorded.   The hottest official temperature ever recorded anywhere in the world was 129.9 degrees, occurring in Death Valley, California on both August 16, 2020, and July 9, 2021. 

The hottest temperature ever recorded in the Arctic was 100.4 degrees on June 20, 2020 in Verkhoyansk in Russia’s Sakha Republic.  (Amazingly, that small town also holds the record for the coldest temperature ever recorded in Asia at -90 degrees). 2021 saw an all-time high temperature recorded in Europe, in Syracuse, Sicily, on August 11 at 119.8 degrees. 

Overall, 400 documented weather stations in communities or outposts worldwide established all-time high temperatures in 2021 alone.  The climate we have lived through over the past decades is changing and these changes will have consequences to our way of life.

**********

Australia hits 123 degrees, tying hottest temperature on record in Southern Hemisphere

Photo, posted January 21, 2013, courtesy of A. Dombrowski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Genetic Variation And Survivability | Earth Wise

By Leave a Comment

A massive but unintended experiment in animal conservation has revealed an unexpected result.  Thousands of desert tortoises moved to a translocation site in Nevada had a greater chance of surviving if they had lots of genetic variation.

From 1997 to 2014, over 9,000 Mojave desert tortoises were moved to a 39-square-mile translocation site in the Ivanpah Valley.  The tortoises were either abandoned pets or were displaced by developments in suburban Las Vegas and by solar farms in the desert.

The U.S. Fish and Wildlife service took blood samples to screen for diseases and marked each animal before releasing them into the site, enabling them to be tracked in later surveys.

When the researchers compared tortoises that lived or died over the same time period after being relocated to the site, they found that survivors averaged 23% greater heterozygosity than those that perished.  Heterozygosity is a measure of genetic variation.  Like most organisms, tortoises have two copies of their entire genome, with one from each parent.  The more those copies differ from each other, the higher the organism’s heterozygosity.

Researchers are not really sure why greater genetic variation is linked to survival rates.  Potentially, individuals with higher heterozygosity have more genomic flexibility.  It is the case that tortoises with more genetic variation have a better chance of having at least one copy of a gene that works really well in stressful or new environments.

Human activity and the changing climate are increasing the need to relocate plants and animals.  Often the chances for success in doing this are not good, so anything we can learn about things that increase the chances for survival can be very important.

**********

Web Links

UCLA study of threatened desert tortoises offers new conservation strategy

Photo, posted August 23, 2016, courtesy of the Bureau of Land Management California via Flickr. Photo by Dana Wilson, BLM.

Earth Wise is a production of WAMC Northeast Public Radio.

Dust And Himalayan Glaciers | Earth Wise

By Leave a Comment

Glaciers in the Himalayas have been melting and retreating, as have glaciers around the world.  As is the case elsewhere, human-driven climate change is a major factor.  But at the lofty heights of the Himalayas, warming temperatures are not the biggest culprit.  Black carbon – released into the air by burning fossil fuels or biomass such as plants, trees, and shrubs – darkens the snow and causes it to absorb more of the sun’s heat.  A recent study by an international team of scientist has identified another important factor:  dust.

An estimated 5 billion tons of desert dust enters the Earth’s atmosphere every year.  Dust from places like Saudi Arabia gets picked up by spring winds and gets deposited on the western sides of mountains, where it can make the air 10 times more polluted than most European cities.  Dust blows across industrial and desert areas in the Indian subcontinent and the Middle East and lands in the Himalayas.  According to the new study, this dust is often the dominant cause of snow melt in those areas.

Desert dust causes snow melt in the same way that black carbon does.   Dirty snow absorbs sunlight more easily than clean snow.

Desert dust is a natural part of Earth’s systems, but the amount of it in the atmosphere has steadily increased since the Industrial Revolution, when humans greatly expanded into desert areas and broke through surface crust that held large amounts of dust in place.

There is not much we can do about desert dust, short of eliminating deserts.  But the disappearance of the Himalayan ice pack – which sustains over a billion people – can be mitigated by reducing greenhouse gas emissions to address climate change .

**********

Web Links

Himalayan glaciers melting because of high-altitude dust

Photo, posted March 13, 2018, courtesy of Sarunas Burdulis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Green Hydrogen | Earth Wise

By Leave a Comment

Saudi Arabia is a country built around oil, but it is now placing a big bet on green hydrogen as the next big thing in its energy future.  The country is constructing a $500 billion futuristic city called Neom in the desert along the Red Sea.  The brand-new city will be home to a million people, and it will be powered by green hydrogen.

The U.S. company Air Products & Chemicals has been building a green hydrogen plant there for the last four years.  The giant plant will be powered by 4 gigawatts of wind and solar projects.

Green hydrogen is hydrogen produced without carbon emissions.  Most hydrogen produced commercially is made from natural gas, which results in CO2 emissions.  Green hydrogen is made by using electricity to split water into its component elements using renewable energy to power the process.

Saudi Arabia is an ideal place for a giant green hydrogen plant.  The Middle East has the world’s cheapest wind and solar power.  The sun reliably shines there almost every day and the wind blows almost every night.

While some proponents argue that hydrogen should fuel the entire energy system, other experts see it as a more targeted solution.  The view is that wind and solar power can provide the electricity we need to power homes and electric cars.  However, green hydrogen could be ideal to power energy-intensive industries like concrete and steel manufacturing, as well as parts of the transportation sector that are more difficult to electrify.

While green hydrogen is barely on the radar in the US, around the world a green hydrogen rush is underway, developing it as an energy source that could help end the reign of fossil fuels.

**********

Web Links

Green Hydrogen: Could It Be Key to a Carbon-Free Economy?

Photo, posted November 6, 2020, courtesy of RSM Chrystie via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Urban Agriculture And Sustainability Goals

By Leave a Comment

In 2016, the City Council of Phoenix, Arizona adopted eight Environmental Sustainability goals for 2050 that lay out the desired long term requirements in order to become a Sustainable Desert City.  Recently, a group of researchers from Arizona State University assessed how urban agriculture can help Phoenix, a desert city of 1.6 million people, meet those sustainability goals.  

Using public records and high-resolution satellite imagery, researchers analyzed the potential benefits of growing crops in three types of urban areas in Phoenix: vacant lots, rooftops, and building facades.  The study, which was supported by the National Science Foundation and the USDA, estimated that there are 28 square miles (or 5.4% of city space) available for urban agriculture.  The data-driven analysis found that 71% of the available areas for urban agriculture would come from existing buildings as opposed to vacant lots. 

All this available space for urban agriculture in Phoenix could supply the city with nearly 183,000 tons of fresh produce annually, which would allow for the delivery of fresh fruits and vegetables to all of the city’s existing food deserts. In fact, the city’s own urban-agriculture output could meet 90% of the fresh produce demand that currently exists in Phoenix. 

In addition to producing food, rooftop agriculture could also reduce the energy use in buildings by 3% per building per year, and displace more than 55,000 tons of CO2 annually.  The use of vacant lots could increase the total Phoenix green space by 17%, and reduce the number of areas lacking green space by 60%.   

This study demonstrates the many different ways that urban agriculture can benefit a city. 

**********

Web Links

Urban agriculture can push the sustainability

Photo, posted May 10, 2011, courtesy of Stephen Zank via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Pulling Water From The Air

By Leave a Comment

A couple of years ago, we reported on the early development of a device that harvests water from the air that even works in the low humidity environment of a desert.  Since then, the researchers from UC Berkeley have continued to improve the device and it is now 10 times better than it was two years ago.

The harvester is based on a porous water-absorbing material called a metal-organic framework, or MOF.  The latest version can pull more than five cups of water from low-humidity air per day for every kilogram of the improved MOF material and that is more than enough water to sustain a person.  The harvester cycles around the clock and is powered by solar panels and a battery.

Previous techniques for condensing water from air at low humidity required cooling down the air to temperatures below freezing, which is not economically practical.  The MOF-based device does not require any cooling.

The Berkeley researchers have formed a startup company – Water Harvester, Inc. – which is now testing and will soon market a device the size of a microwave oven that can supply 7 to 10 liters of water per day, which is enough drinking and cooking water for two or three adults.

An even larger version of the harvester, which would be the size of a small refrigerator, would provide 200 to 250 liters of water per day, enough for a household to drink, cook, and shower.  The new company envisions a village-scale harvester that would produce 20,000 liters per day, still running off of solar panels and a battery.

Water Harvester believes the water needs for many people can come out of the thin air.

**********

Web Links

Water harvester makes it easy to quench your thirst in the desert

Photo courtesy of Grant Glover (University of South Alabama) via UC Berkeley.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cockroaches Of The Ocean

By Leave a Comment

The coast of Northern California is home to underwater forests – huge, sprawling tangles of brown seaweed.  Kelp forests play a similar role in the oceans as the one that ordinary tree forests play on land.  Like trees, kelp absorbs carbon emissions and provides critical habitat and food for a wide range of species.

[Read more…] about The Cockroaches Of The Ocean

The High Cost Of The Cloud

By Leave a Comment

More and more often we make use of “the cloud” – that mysterious place where we store, move, process and analyze data.  We keep our photos there.  We stream music and videos from there.  We do our work there.  Perhaps we have a mental image of all of this digital information floating above our heads in some ethereal way:  like in a cloud.

[Read more…] about The High Cost Of The Cloud

Super Blooms

By Leave a Comment

This past August one of the driest regions on Earth transformed from a barren desert to a sea of colorful flowers.  Heavy rains in Chile’s Atacama Desert caused the phenomenon, locally known as the desierto florido or flowering desert.   These things typically only happen every five to seven years, but the previous super bloom actually took place in 2015.

[Read more…] about Super Blooms

Sahara Greening And Tropical Cyclones

By

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.

[Read more…] about Sahara Greening And Tropical Cyclones

Did People Create The Sahara Desert?

By

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.

[Read more…] about Did People Create The Sahara Desert?

Saving Saharan Oases

By

An oasis is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source such as a pond or a small lake.  Oases can provide habitat for animals as well as people.   Oases have long been essential for trade and transportation routes in desert areas; caravans typically travel via oases so that supplies of water and food can be replenished.

[Read more…] about Saving Saharan Oases

Floating Solar

By

Installing solar arrays on the surface of bodies of water is an idea that is catching on around the world.  Such installations are especially attractive in places like Japan, where land resources are scarce.  In the UK, there are a couple of these so-called “floatovoltaic” projects underway – one outside of London and one near Manchester.

[Read more…] about Floating Solar

Solar Power In Las Vegas

By

The Las Vegas Strip has been referred to as an energy consumption nightmare.  Just one look at the place provides evidence for the claim:  an endless sea of lights, glitz and glamour and cavernous casinos running huge banks of air conditioning equipment in the desert heat.  Even with Boulder Dam a hop, skip and jump away, Vegas is struggling to meet its electricity needs.

[Read more…] about Solar Power In Las Vegas

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)