Reuters reported on Wednesday that China’s environmental ministry has okayed the construction of a new hydroelectric dam on the Dadu River in the Sichuan province, which when completed will be the country’s largest.

China’s energy mix was 9.4 percent renewable as of 2011, and the Sichuan project is part of the country’s effort to boost itself to 15 percent by 2020. Hydroelectric power is anticipated to make up most of that increase.

The environmental ministry acknowledged that the project is massive enough to damage the local ecology, negatively effecting certain rare fish species and plant life. The dam’s developers have promised to try and offset those effects with “counter-measures,” and the project still requires the approval of China’s ruling cabinet.

To be built over 10 years by a subsidiary of state power firm Guodian Group, it is expected to cost 24.68 billion yuan ($4.02 billion) in investment.

The ministry, in a statement issued late on Tuesday, said an environmental impact assessment had acknowledged that the project would have a negative impact on rare fish and flora and affect protected local nature reserves.

Developers, it said, had pledged to take “counter-measures” to mitigate the effects.

Right now the title for China’s tallest dam goes to the Xiaowan project, at 292 meters, while the tallest dam in the world is currently Tajikistan’s Nurek dam, at 300 meters. The Sichuan dam will top 314 meters when all is said and done.

China has been at the forefront of hydroelectric development for a while now, with an enormous number of dams either constructed, in the works, or in the planning stages. Even individual projects can be of tremendous scale, providing in at least one instance an electrical capacity equal to nearly half of Britain’s entire national grid, and preventing 200 metric tons of carbon emissions each year. As of 2010, worldwide hydroelectric capacity was 850 to 900 gigawatts, meaning about one-fifth of the world’s electricity — and half the electricity for almost two thirds of the world’s countries — comes courtesy of hydropower. Though that use varies widely: the United States and Europe have developed 70 and 75 percent of their hydroelectric potential, while Africa has only taken advantage of 7 percent.

At the same time, the large bodies of water and massive landscape alterations that are part and parcel of large dam projects mean hydroelectricity can come with unusually significant downsides. The construction of the Three Gorges Dam in China’s Hubei province, for example, caused significant ecological damage, increased the risk of landslides, flooded a number of archeological and cultural sites, and displaced 1.3 million people. And the constricted water flow can hurt downstream populations that rely on the rivers for their fresh water supplies.

Meanwhile, climate change itself is also making hydropower less reliable, as altering weather patterns dry up some river flows, boost others, and generally make the future availability of water flows more difficult to predict.

One answer to those challenges could be small scale hydropower. Studies suggest there’s as much as 30 gigawatts of unused potential for such projects in the United States. These set-ups generally provide 10 kilowatts to 30 megawatts a piece, and don’t require damming rivers. (Or they can be built into already existing dams, the vast majority of which are not hydroelectric.) Unfortunately, regulatory red tape is in many ways the major hurdle to taking advantage of small scale hydro.

One challenge that continues to hound solar power is the efficiency with which it converts sunlight into electrical power. Right now, that efficiency ranges from 10 to 30 percent, while much of the rest is lost as waste heat. But Swiss researchers associated with IBM have built a new solar dish, called the High Concentration PhotoVoltaic Thermal system (HCPVT), that tackles the waste heat problem by using it to generate fresh water.

The dish itself is covered in small mirrors, which concentrate sunlight on a small module of photovoltaic cells. That design puts the dish at the leading edge of efficiency, converting 30 percent of the received solar radiation into electricity and providing 25 kilowatts of power. But it also means the solar module faces an enormous concentration of heat. To keep it from melting, the HCPVT employs a liquid coolant system that IBM first developed for its high-performance computers, and that’s 10 times more effective than traditional passive air cooling.

The liquid keeps the solar cells operating safely at up to 5,000 times the normal solar concentration by drawing away the waste heat, after which the heated coolant is used to vaporize salty water in a desalinization system. As a result, the HCPVT is able to recover half the waste heat and put it to productive use.

According to IBM, the HCPVT is built from unusually low-cost materials, meaning the per area price of setting it up is significantly lower than comparable solar systems, as is the cost per kilowatt hour:

“We plan to use triple-junction photovoltaic cells on a micro-channel cooled module which can directly convert more than 30 percent of collected solar radiation into electrical energy and allow for the efficient recovery of an additional 50 percent waste heat,” said Bruno Michel, manager, advanced thermal packaging at IBM Research. “We believe that we can achieve this with a very practical design that is made of lightweight and high strength concrete, which is used in bridges, and primary optics composed of inexpensive pneumatic mirrors — it’s frugal innovation, but builds on decades of experience in microtechnology….

With such a high concentration and a radically low cost design scientists believe they can achieve a cost per aperture area below $250 per square meter, which is three times lower than comparable systems. The levelized cost of energy will be less than 10 cents per kilowatt hour (KWh). For comparison, feed in tariffs for electrical energy in Germany are currently still larger than 25 cents per KWh and production cost at coal power stations are around 5-10 cents per KWh.

Just one square meter of receiver area in the HCPVT system can provide 30 to 40 liters of drinkable water per day — about half the needed daily amount for the average person, according to the United Nations. The researchers think a large array of the dishes could produce enough fresh water to sustain a town. On top of that, the system can even provide air conditioning, using an absorption chiller rather than the standard compression chiller:

The HCPVT system can also provide air conditioning by means of a thermal driven adsorption chiller. An adsorption chiller is a device that converts heat into cooling via a thermal cycle applied to an absorber made from silica gel, for example. Adsorption chillers, with water as working fluid, can replace compression chillers, which stress electrical grids in hot climates and contain working fluids that are harmful to the ozone layer.

The prototype is being tested at IBM research facilities in Zurich, and the project was recently awarded a three-year, $2.4 million grant from the Swiss Commission for Technology and Innovation. The long-term vision is to build arrays in areas of southern Europe, Africa, the Arabic Peninsula, South America, Australia, and the southwestern United States — places that are remote, dry, and in need of both affordable sustainable energy and greater supplies of drinking water.

Last week, David Roberts over at Grist flagged a report carried out by the environmental consultant group Trucost, at the behest of The Economics of Ecosystems and Biodiversity over at the United Nations.

The idea behind the report was simple. Tally up all the world’s natural capital — land, water, atmosphere, etc. — that doesn’t currently have a dollar value attached to it, and figure out the price. But the next step was where it got interesting. Figure how much of that natural capital is being consumed, depleted or degraded without the responsible party paying the cost for that use. The number the study hit on was a staggering $7.3 trillion in 2009 — about 13 percent of global economic output for that year.

This brings up what economists call “negative externalities.” That’s a technical term for what happens when one actor in the economy has to pay for another actor’s mess. In a theoretically perfect market, the price of consuming, degrading or depleting a resource would be paid by the party responsible.

But getting the theory of markets to map onto the real world is difficult. Dumping trash on a neighbor’s lawn is technically free, so a lot of us should be doing it more. But because we’ve built societies in which our neighbor can sue us, or the cops can fine us, we’re forced to internalize that cost. Lots of costs can only be internalized through smart institutional design and government policy, rather than by leaving the markets free to do their market thing.

What Trucost found is that when you scale this problem up globally — all the river, air, and land and air pollution that isn’t paid for, all the water and land use that isn’t paid for, and especially all the carbon emissions dumped into the atmosphere that aren’t paid for — the numbers get very big:

Global Greenhouse Gas Emissions: $2.7 trillion. This was by far the biggest single problem, and East Asia and North America were the two biggest culprits. That lines up with an International Monetary Fund study that determined the United States is the world’s biggest subsidizer of fossil fuels — with Asia the runner-up — because it’s failed to put a price on carbon emissions through a carbon tax or a cap-and-trade system. Trucost assumed a social cost to carbon emissions of $106 per metric ton. That’s higher than the IMF’s assumption of $25 per ton, but well within the overall range of costs studies have found.

Global Water Consumption: $1.9 trillion. Wheat farming was the biggest problem here, followed by rice farming and general water supply, mainly in Asia and North Africa. That’s probably largely because developing and poorer countries have fewer institutions or infrastructure for managing water use.

Global Land Use: $1.8 trillion. Cattle ranching in South America came in first here, followed by cattle ranching in South Asia. Besides the usual uses, the effects of logging and fishing were also included. Trucost estimated the value of unused land using metrics laid out in the United Nations’ Millennium Ecosystem Assessment.

Global Waste And Land, Air, And Water Pollution: $850 billion. Sulfur dioxides, nitrogen oxides, and particulate emissions were the big culprits for air pollution ($500 billion total) mainly in North America, East Asia, and Western Europe. Land and water pollution ($300 billion total) was actually mostly fertilizers, from North America, Asia, and Europe again. Global waste was the remainder, mostly hazardous materials. Trucost figured out these prices mainly through the costs of clean-up and health effects.

On top of that, the study’s next conclusion was equally dramatic: whole sectors of power generation, materials production, farming and ranching across the globe would become entirely unprofitable if they had to pay the true cost of their natural capital use. The top five biggest regional industries the study looked at are in the chart below, and even in the best case their natural capital costs effectively wipe out their revenues:

In fact, of the twenty biggest regional industries the researchers examined around the globe, none of them would be profitable. Much of the global economy, in other words, is a giant Ponzi scheme that is (temporarily) viable only because markets fail to account for the value and use of the natural ecology — on which civilization depends for its crops, water, air, its very livelihood.

But that bill will ultimately be paid in full are — by our children and countless future generations.

The Consequences For The Economy

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A jury in New Hampshire found ExxonMobil guilty of negligence for contaminating drinking water with MTBE, a gasoline additive.

A New Hampshire jury found Exxon Mobil Corp. negligent in adding MTBE to gasoline and contaminating the state’s drinking water. The jury will continue to deliberate to determine what the company will pay in damages.

Exxon Mobil, the last defendant in the state’s lawsuit, had been on trial since Jan. 14 in Concord. The jury announced its partial verdict today about two hours after it began to deliberate.

The state is seeking monetary damages from Exxon Mobil based on its share of gasoline sales in New Hampshire during the period covered by the suit. Jurors said today that the market share was 29 percent. With a projected cost of $816 million to test, monitor and clean up wells, New Hampshire asked the jury to award it $236 million.

All other oil companies named in the suit (Shell, Sunoco, ConocoPhillips, Irving Oil, Vitol SA, Hess, and Citgo) have already settled with the state. Exxon was the lone holdout. Other suits in other states stemming from action started in 2000 have been consolidated in federal court and have not gone to trial yet.

What did the jury find compelling in the state’s argument? We may never know exactly, but there is probably more to it than the fact that the company made billions in profits while paying a minuscule tax rate as gasoline prices soared last year.

MTBE increases the oxygen content of fuel, making it burn more completely. Witnesses told the jury that the ethanol could have been used in place of MTBE, which causes tumors and other illnesses in rats and mice. Ethanol, for all its drawbacks (which may eventually decrease), does not do that. They estimated that 5,590 New Hampshire wells had MBTE levels that were unfit for drinking water.

So Exxon lost a court case (which it will appeal) for negligently poisoning drinking water. Exxon is also fighting EPA rules that make cars run more efficiently and use less gasoline. It dodges paying taxes on pumping tar sands oil through (and occasionally spilling it on) America.

No matter which gasoline additive is used, the fuel still gets burned, which puts more carbon pollution into the atmosphere and helps cause climate change. Efficient engines and reducing the amount of fuel is the best way to stop all types of pollution.

New York Times columnist Thomas Friedman has a new piece out today on a report that investigates the web of interconnections between climate change and global insecurity, particularly in the Arab Spring.

“The Arab Spring and Climate Change” is a product of cooperative efforts between the Center for American Progress (CAP), the Stimson Center, and the Center for Climate and Security. The report “doesn’t claim that climate change caused the recent wave of Arab revolutions,” Friedman writes. “But, taken together, the essays make a strong case that the interplay between climate change, food prices (particularly wheat) and politics is a hidden stressor that helped to fuel the revolutions and will continue to make consolidating them into stable democracies much more difficult.”

Anne-Marie Slaughter, one of the report’s lead authors, used the preface of the report to lay out the idea of a “stressor” as a useful framework for thinking about these issues. Borrowed from criminal science concepts, a stressor is a “sudden change in circumstances or environment” that interacts with a complicated web of other factors (often a psychological profile, in criminal science’s case) to create sudden, unforeseen, and volatile change. In this instance, climate shifts such as drought our heat waves act as stressors on everything from crop production to food security, water security, the migration of peoples, the stability of governmental and non-governmental networks, and the informal associations and interactions of both local and more widespread communities.

As Friedman points out, these forces can layer on top of one another in ways that make the world more insecure — instigating, shifting, or intensifying geopolitical events such as the recent uprisings in the Arab world:

[T]this collection of essays opens with the Oxford University geographer Troy Sternberg, who demonstrates how in 2010-11, in tandem with the Arab awakenings, “a once-in-a-century winter drought in China” — combined, at the same time, with record-breaking heat waves or floods in other key wheat-growing countries (Ukraine, Russia, Canada and Australia) — “contributed to global wheat shortages and skyrocketing bread prices” in wheat-importing states, most of which are in the Arab world.

Only a small fraction — 6 percent to 18 percent — of annual global wheat production is traded across borders, explained Sternberg, “so any decrease in world supply contributes to a sharp rise in wheat prices and has a serious economic impact in countries such as Egypt, the largest wheat importer in the world.”

The numbers tell the story: “Bread provides one-third of the caloric intake in Egypt, a country where 38 percent of income is spent on food,” notes Sternberg. “The doubling of global wheat prices — from $157/metric ton in June 2010 to $326/metric ton in February 2011 — thus significantly impacted the country’s food supply and availability.” Global food prices peaked at an all-time high in March 2011, shortly after President Hosni Mubarak was toppled in Egypt.

As Friedman notes, the top nine global wheat importers are Middle Eastern countries, leaving them especially vulnerable to price or supply shocks brought on by climate change. And that vulnerability lines up with the potential for destabilization: in 2011, seven of those nine countries suffered political protests that killed civillians. Moreover, households in those countries spend over 35 percent of their incomes on food on average, versus less than 10 percent in developed countries. “Everything is linked,” Friedman says. “Chinese drought and Russian bushfires produced wheat shortages leading to higher bread prices fueling protests in Tahrir Square. Sternberg calls it the globalization of ‘hazard’”:

In 2009, [the study's co-editors] noted, the U.N. and other international agencies reported that more than 800,000 Syrians lost their entire livelihoods as a result of the great drought, which led to “a massive exodus of farmers, herders, and agriculturally dependent rural families from the Syrian countryside to the cities,” fueling unrest. The future does not look much brighter. “On a scale of wetness conditions,” Femia and Werrell note, “‘where a reading of -4 or below is considered extreme drought,’ a 2010 report by the National Center for Atmospheric Research shows that Syria and its neighbors face projected readings of -8 to -15 as a result of climatic changes in the next 25 years.” Similar trends, they note, are true for Libya, whose “primary source of water is a finite cache of fossilized groundwater, which already has been severely stressed while coastal aquifers have been progressively invaded by seawater.”

As ThinkProgress’ Hayes Brown reported, Friedman and Slaughter recently sat down with Michael Werz in front of a packed house at CAP to discuss the implications of the report:

Friedman implored the audience to think of the Middle East not by the current national borders, but instead envisioning as overlaid maps of culture and climate to understand the region. Slaughter took the concept a step further, adding in maps of political networks — government, corporate, NGOs, and others — and seeing where the larger “nodes” in those networks exist. Tracing where those nodes intersect, Slaughter said, shows where policy can be made.

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Rachel Nuwer via Take Part

In 1922 the conservationist Aldo Leopold canoed through a lush, verdant delta full of green lagoons, darting fish and squawking waterfowl. But Leopold’s “milk and honey wilderness,” where the Colorado River empties into Mexico’s Gulf of California, ceased to exist decades ago. In its stead, a cracked, barren mudflat stretches for miles.

“If we choose, we can have healthy rivers alongside healthy economies,” Postel said. “We don’t have to be running our rivers dry.”

“This amazing place does not exist anymore,” said Sandra Postel, director of the Global Water Policy Project and freshwater fellow of the National Geographic Society. “A lot was lost.”

Ten major dams — from the Hoover Dam, erected in 1936, to the Glen Canyon Dam, completed in 1966 — block the flow of the Colorado River. Countless towns and industries siphon water from the river and its many tributaries as it meanders to the sea. Today the Colorado River joins the likes of the Indus, the Rio Grande, the Nile and other major world rivers that are so over-tapped they no longer reach the sea for long stretches of time. “This is one of America’s iconic rivers,” Postel said. “I don’t think this country would be the one we know today without the Colorado.”

It does not have to be this way, however. A restoration and outreach effort called Change the Course seeks to return the river to the sea. To pursue this goal, the National Geographic Society, the Bonneville Environmental Foundation, and Participant Media teamed up and pooled their expertise — science, social media, storytelling and policy — to change the fate of the once-mighty Colorado River.

A key to the campaign’s potential success rests on reversing more than 100 years of water use along the river. Since the mid-1800s, the Colorado River’s water was legally divided amongst farmers, landowners and ranchers along its course. Then, in the 1920s, seven states in the Colorado basin were allowed to divert additional water for cities, agriculture and industry. The result: more people have rights to divert water than the river has water to supply.

The clincher, however, is this: water rights holders have to “use it or lose it.” If a stakeholder does not divert his allocated amount of water from the river each year, he may lose those rights.

Bonneville Environmental Foundation, a nonprofit based in Portland, seized upon this idea.

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As climate change makes the regions of the West, Southwest, and Great Plains warmer and drier, water demand will continue to increase, and the combined effect will place an ever greater burden on the country’s fresh water supplies — possibly completely draining important reservoirs in those areas, under some scenarios. That’s according to a new study authored by researchers with Colorado State University, Princeton and the U.S. Forest Service, and flagged yesterday by Summit County Citizens Voice.

This is consistent with other studies on the risk of future water shortages: The Department of the Interior is anticipating that by 2060 the gap between river supply and water demand in the states of the Colorado River Basin will be 3.2 million acre feet due to climate change. Research published in Environmental Science and Technology found that by 2050 one third of U.S. counties could face “high” or “extreme” risk of water shortage. And the International Energy Agency determined that if current policies remain in place, fresh water use by the energy industry alone could more than double — from 66 to 135 billion cubic meters annually by 2035.

Climate change, substantially driven by global warming and humanity’s carbon emissions, is anticipated to lead to more weather extremes in various areas — longer periods of low precipitation and water shortage in many areas, interspersed with greater deluges. And, of course, higher average temperatures to bake the same regions as they dry out. The Forest Service study used a number of different scenarios in its models, assuming different levels of future population growth, economic growth, and temperature increases:

[F]uture climate change will increase water use for agricultural irrigation and landscape maintenance in response to rising plant water requirements, and at thermoelectric plants to accommodate rising electricity demands for space cooling. Including these effects, per-capita withdrawals are projected to drop only moderately for the next few decades and then level off as the effects of climate change become greater, and total withdrawals are projected to rise nearly continuously into the future. Projected withdrawals differ across the global emissions scenarios examined, especially in the latter decades of the century.

Although precipitation is projected to increase in much of the United States with future climate change, in most locations that additional precipitation will merely accommodate rising evapotranspiration demand in response to temperature increases. Where the effect of rising evapotranspiration exceeds the effect of increasing precipitation, and where precipitation actually declines, as is likely in parts of the Southwest, water yields are projected to decline. For the United States as a whole, the declines are substantial, exceeding 30% of current levels by 2080 for some scenarios examined.

Here’s just one example of several permutations the study did, laying out the changes in future water yields in 2020, 2040, 2060 and 2080. The A1B scenarios were relatively middle-of-the-road, assuming medium population growth, high economic growth, and medium temperature increases in the future:

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The International Energy Agency concluded that freshwater use is becoming an increasingly crucial issue for energy production around the world in its 2012 World Energy Outlook.

Between steam systems for coal plants, cooling for nuclear plants, fracking for natural gas wells, irrigation for biofuel crops, and myriad other uses, energy production consumed 66 billion cubic meters (BCM) of the world’s fresh water in 2010. That is water removed from its source and lost to evaporation, consumption, or transported out of the water basin — as opposed to water withdrawn, used, and then returned to its source for further availability, which is a far larger amount.

According to figures it shared with National Geographic, IEA anticipates this water consumption will double from 66 BCM now to 135 BCM by 2035 with most of the growth accounted for by coal and biofuels:

If today’s policies remain in place, the IEA calculates that water consumed for energy production would increase from 66 billion cubic meters (bcm) today to 135 bcm annually by 2035.

That’s an amount equal to the residential water use of every person in the United States over three years, or 90 days’ discharge of the Mississippi River. It would be four times the volume of the largest U.S. reservoir, Hoover Dam’s Lake Mead.

More than half of that drain would be from coal-fired power plants and 30 percent attributable to biofuel production, in IEA’s view. The agency estimates oil and natural gas production together would account for 10 percent of global energy-related water demand in 2035….

The surest way to reduce the water required for electricity generation, IEA’s figures indicate, would be to move to alternative fuels. Renewable energy provides the greatest opportunity: Wind and solar photovoltaic power have such minimal water needs they account for less than one percent of water consumption for energy now and in the future, by IEA’s calculations.

This presents a challenge, since river flows, aquifers, and other sources of fresh water are already being strained by the twin drains of population growth and less reliable rainfall due to climate change. The United Nations is projecting that by 2025, 1.8 billion people will live in regions with severe water scarcity, and two-thirds of the world’s population could be living under water-stressed conditions. Given water’s importance in different forms of energy production, this presents a double hit: Less available fresh water for human consumption, plus strained and costlier energy supplies.

IEA sees water consumption for coal electricity shooting up 84 percent, from 38 to 70 BCM per year by 2035. So-called “dry cooling” systems could address this, but the plants cost more and generate electricity less efficiently. Nor is carbon capture and sequestration technology likely to help.

While biofuels’ water consumption will be lower than coal’s — 41 BCM in 2035, up from 12 BCM today — its increase of 242 percent will be much larger. Irrigation requires a lot of water, though estimates vary wildly and the industry claims it’s finding ways to cut back. IEA puts it between four and 560 gallons of water needed to produce one gallon of corn ethanol. Other estimates put it as high as 10,000 gallons of water per one gallon of biofuel. And that’s all bound up with the damaging effect biofuel production is having on world food supplies.

There are solutions, such as moving to less water-intensive methods like pump irrigation, but the trade-off is far more electricity use from potentially unsustainable sources. Cellulosic ethanol, made from non-food sources, is another possibility, but IEA estimates it won’t be commercially viable until at least 2025.

Also, as National Geographic notes, biofuels’ level of water consumption is grossly out of whack with their contributions to world energy supplies: They provide a mere 3 percent of the energy that drives cars, trucks, ships, and aircraft, and IEA projects they’ll increase to just 5 percent by 2035 under current government policies.

As for fracking, IEA’s estimates covered the entire source-to-carrier production process, and under this framework natural gas’ water consumption reach just 2.85 BCM by 2035, or 2 percent of total consumption. Though the concentration of water use at individual fracking projects can still put a strain on water supplies for local commentaries.

The first pilot plant in a program of installations that can sustainably produce crops, electricity, biofuels, and even plants for re-vegetation efforts in a desert environment is now up and running in the Middle Eastern nation of Qatar.

The Sahara Forest Project, which brings outfits from both Qatar and Norway together, uses desert air, sunlight, and saltwater as inputs for a system that aims to be environmentally sustainable, beneficial for local human development, and financially viable over the long term. As the project’s CEO, Joakim Hauge, puts it: “The Sahara Forest Project is all about taking what we have enough of, like saltwater, CO2, sunlight, and deserts, to produce what we need more of: sustainably produced food, water, and energy.” The hope is that the pilot project can be scaled up to installations in drier and desert climates around the world.

Essentially, the plant takes multiple sustainable technologies and integrates their inputs and outputs into a single multistage system, thus minimizing both waste and ecological footprint:

• Standard solar power and concentrated solar power: Arrays of mirrors create concentrated solar power by aiming sunlight to superheat seawater into steam. That steam can then drive turbines to create electricity, and the heated seawater is then used throughout the greenhouse system. Additional sustainable electricity is generated from arrays of standard solar photovoltaic panels.
• Saltwater for fresh water and cool air for greenhouses: Hot desert air is pulled through a flow of seawater as it enters the greenhouses. This both cools and humidifies the air, creating optimal growing conditions for the agricultural crops within. At the far end of the greenhouse, the air is heated by flows of sun-heated seawater and then encounters pipes of cooled seawater, which causes the humidity to condense into fresh water that is then used for crop irrigation.
• Outdoor vegetation: Outside the greenhouses, the seawater passes through further evaporators to create humidity for vegetation sheltered outdoors. These include trees for desert reforestation, local vegetation, various forms of crops and livestock feed, and specific forms of plants naturally adapted to salt water which serve as feedstocks for bioenergy production and other uses. At the end, remaining seawater is collected into evaporation pools for the production of salt.
• Algae biofuel production: Lab-grown algae, which have been shown to generate up to 30 times more biofuel per acre than other plants, are grown in saltwater pools to create biofuels without taking up agricultural land or crops that double as food for humans.

The basic advantage of the Sahara Forest Project is that it doesn’t use any fundamentally new or experimental technology — it merely recombines established technologies in creative ways.

At the same time, at least one of its goals — growing plants for reforestation — may be overly ambitious. “Trying to grow trees in the Sahara desert is not the most appropriate approach,” Patrick Gonzalez, a forest ecologist at the University of California, Berkeley, told National Geographic back in 2010. “I can imagine that this scheme and type of technology in limited cases might work in certain areas like Dubai, where they’re used to making palm-shaped islands and 160-story-tall buildings.”

But for the more modest goal of returning a desert to its natural former ecosystem, “it would be more effective, but less flashy, to work with local people on community-based natural-resource management.”