Coming to a desert far, far away from you?
What’s the News: Server farms are the Hummers of the information age: they use a substantial 1.5% of the world’s electricity, and that number’s growing fast. But by sticking them out in the middle of sunny, windy nowhere, computer scientists posit, we could make use of renewable energy that’s otherwise too far from civilization to be used.
The Sahara is the world largest desert, and getting larger. It threatens to creep ever further to the south and turn arable land in desert wasteland. The nations in its path have an idea, though: We’ll build a fence. Of trees.
The “Great Green Wall” would be a tree band that spans the breadth of northern Africa, 9 miles wide and nearly 5,000 miles long, from Senegal at the western edge near the Atlantic to Djibouti on the eastern edge near the pirate-infested Gulf of Aden. It may sound too dreamy or crazy to ever go forward, but this week at a meeting in Chad about desertification, the Global Environment Facility backed the belt idea with $119 million. Chad’s minister of environment, Hassan Térap, says it can be achieved:
When asked if the long-discussed but yet-to-be funded Green Wall initiative was too ambitious, Térap told IRIN: “We have to attack the problem, long ignored, through vision, ambition – and trees. What is wrong with ambition?” [IRIN Africa].
When European Union officials first discussed the idea of a massive solar power plant in the Sahara to provide power to all of Europe, many people took it as a thought experiment, a plan that was far too outlandish to ever come to pass. But now a band of alternative energy companies have announced the formation of a consortium dedicated to pushing the project ahead.
The Desertec Industrial Initiative (DII) aims to provide 15% of Europe’s electricity by 2050 or earlier via power lines stretching across the desert and Mediterranean sea. The German-led consortium was brought together by Munich Re, the world’s biggest reinsurer, and consists of some of country’s biggest engineering and power companies [The Guardian].
A team of researchers has come up with a simple plan to halt global warming: All we need to do is turn both the Sahara and the Australian outback into vast, shady forests.
While that might sound so ambitious as to be absurd, the climate scientists say the project would be no more expensive or technologically challenging than some of the other geoengineering schemes that are currently under discussion. And researcher Leonard Ornstein says it would certainly get results. Ornstein says that if most of the Sahara and Australian outback were planted with fast-growing trees like eucalyptus, the forests could draw down about 8 billion tons of carbon a year–nearly as much as people emit from burning fossil fuels and forests today. As the forests matured, they could continue taking up this much carbon for decades [ScienceNOW Daily News].
To stop the spread of the Sahara Desert, one innovative thinker has proposed a bold plan: a wall along the southern border of the desert that would hold back the advancing dunes. Swedish architect Magnus Larsson says the wall would effectively be made by “freezing” the shifting sand dunes, turning them into sandstone. “The idea is to stop the desert using the desert itself,” he said. The sand grains would be bound together using a bacterium called Bacillus pasteurii commonly found in wetlands.” It is a microorganism which chemically produces calcite – a kind of natural cement” [BBC News].
Larsson is already well-known in the field thanks to his proposed Great Green Wall, a 4,349 mile line of trees stretching across Africa to stop desertification [Fast Company]. The sandstone wall could compliment the green wall, Larsson says, because if people chopped down the trees for firewood the sandstone wall would still remain.
The Mojave Desert has become a battlefield for how President Obama’s clean energy goals should be moved forward, and conservationists and renewable energy advocates, usually natural allies, are now pitted against each other. California Senator Dianne Feinstein proposed legislation last week that would designate more than 800,000 acres of desert land a national monument, putting it off-limits to energy projects.
The area of concern to Feinstein is between the Mojave National Preserve and Joshua Tree National Park…. The area includes desert tortoise habitat, wildlife corridors, cactus gardens and the Amboy Crater [Los Angeles Times]. While many believe that the desert is an ideal location to establish solar and wind farms, conservationists say that such projects would destroy the ecosystem. David Myers, head of the Wildlands Conservancy, says, “How can you say you’re going to blade off hundreds of thousands of acres of earth to preserve the Earth?” [The New York Times].
Myers stands firmly on one side, while other environmentalists are working with the state on its renewable energy plans for the desert. “We have to accept our responsibility that something that we have been advocating for decades is about to happen. My job is to make sure that it happens in an environmentally responsible way” [The New York Times], says Johanna Wald of the Natural Resources Defense Council.
Defying its predecessors, SandBot is the first robot able to traverse sand. Robots normally face the same difficulties as humans when trying to walk across sand, often getting stuck or digging themselves into a rut, and even SandBot had trouble in its first trials. Like a car spinning its tires only to sink deeper, SandBot’s legs moved so quickly that the entire robot simply sank [Discovery News]. However, a few tweaks to its speed and the motion of limbs soon had it cruising like a veritable dune buggy.
The SandBot model is inspired by the movements of desert animals such as lizards and cockroaches. Instead of moving through sand at a steady rate, the new robot is designed with six limbs, three of which move slowly while in contact with the sand, while the others rotate quickly through the air to position themselves for the next step (see the video). In a year of trials, SandBot eventually traversed a track of “sand” made out of poppy seeds at a speed of about 30 centimeters per second, or at least 15 times faster than the Mars rovers [ScienceNOW Daily News].
The first migration of Homo sapiens, when they left the East African landscapes where they evolved and began a long trek across the Sahara, may have followed a different route than previously believed. A new study shows that prehistoric river channels fed by monsoons once traced a path north through the desert and argues that the modern humans may have followed those channels, going from oasis to oasis until they reached the sea.
The Sahara has had several periods of increased rainfall that made it a wetter and greener place, including one interlude between 130,000 to 170,000 years ago when the researchers believe these river channels flowed with water. Now only visible with satellite radar, the channels flowed intermittently from present-day Libya and Chad to the Mediterranean Sea, says [lead researcher] Anne Osborne…. Up to five kilometres wide, the channels would have provided a lush route from East Africa – where modern humans first evolved – to the Middle East, a likely second stop on Homo sapiens‘ world tour [New Scientist].
A team of architects and environmental engineers has proposed covering swaths of the Sahara with vast “salt water greenhouses” powered by solar power arrays, in a plan they call the Sahara Forest Project. Charlie Paton, inventor of the salt water greenhouse, says the combined technologies could transform patches of the desert from arid wastelands into lush expanses that produce a bounty of fruits and vegetables for local people.
The plan is no doubt ambitious and unproved at this scale, but Paton says he has built demonstration greenhouses on the Spanish island Tenerife, as well as in Abu Dhabi and Oman; he says there is further interest in funding demonstration projects from across the Middle East, including UAE, Oman, Bahrain, Qatar and Kuwait. The cost is not as astronomical as one would think, and is estimated at approximately $118 million for a 20 hectare [50 acre] site of greenhouses and a 10MW concentrated solar power farm [Red Herring]. Paton is working with Exploration Architecture, a company that worked on the world’s largest greenhouse in England’s Eden Project.
In an arid and lifeless stretch of the Sahara, archaeologists have discovered a massive graveyard and remnants of early settlements that hark back to Stone Age days when the desert was wet, green, and habitable. Researchers say the find is a striking reminder that climates and environments can shift drastically over the geologically short time period of 10,000 years.
In an area of Sahara that’s known to nomads as the “desert within a desert,” researchers found evidence of thriving prehistoric cultures and rich ecosystems on the edge of a lake. There were also hundreds of animal bones. In addition to antelope and giraffe, [lead researcher Paul] Sereno quickly recognized the remains of water-adapted creatures like crocodiles and hippos, then turtles, fish, and clams. “Everywhere you turned, there were bones belonging to animals that don’t live in the desert,” said Sereno. “I realized we were in the Green Sahara” [National Geographic].