In New York and Pennsylvania, a technique that splits rock so natural gas can flow is pitting environmentalists against industry and neighbor against neighbor.

In areas distant from the surge of natural gas drilling that has swept western states over the past 20 years or so, high-pressure fracturing, or “fracking,” has raised a fundamental question: Can a huge supply of deep natural gas be developed without harming rural landscapes and poisoning the groundwater that most people drink?

Nationwide, fracking is now used not only to liberate gas from shale, but also to boost production in the majority of oil and gas wells. In an era of energy shortages, it’s difficult to dismiss a massive new supply of natural gas, the cleanest fossil fuel, and the gas industry is quick to position fracking as a key to jobs, prosperity and energy security.

But critics charge that fracking pollutes water and causes excess noise, truck traffic and health hazards. They reject the conversion of rural landscapes into what they call “industrial landscapes.”

Update Dec. 9, 2011: On Dec. 8, the Associated Press reported on an Environmental Protection Agency finding “that compounds likely associated with fracking chemicals had been detected in the groundwater beneath Pavillion, a small community in central Wyoming where residents say their well water reeks of chemicals.” Despite the differences in geology and fracking technology between Wyoming and the eastern gas deposits, the finding adds fuel to the contention that fracking can harm groundwater. End update.

The middle ground on the fracking debate seems as lonely as the far side of moon. But could both sides have some valid arguments? And if so, where do we go from here?

Context for the contest

Natural gas was once flared off as junk at oil wells, but it began to enter the energy markets in the 1920s. By now, it’s one of the big three sources of energy in the United States, alongside coal and oil.

Ten or 15 years ago, rising prices heralded a shortage of natural gas, a clean fossil fuel containing mostly methane that has become a major energy source for electricity and home heating over the past 50 years or so.

Those prices helped spark a two-legged technological revolution composed of fracking and horizontal drilling. Fracturing rock allows gas to flow. Horizontal drilling allows one well to tap a profitable volume of a thin, gas-rich wafer of deep shale.

The power of this combination is evident in the frenzy to lock up land above the Marcellus shale, a rock body that underlies parts of Pennsylvania, New York, Ohio and West Virginia, and in the rising estimates for future gas production.

At the same time, “fracking” has become the “brand name” for more generalized opposition to gas drilling, and the debate is confused by the fact that many people use “fracking” as shorthand for new gas development rather than the process that breaks rock so gas can flow. This matters: Although fracking fluids can pose a hazard to groundwater, many gas wells contain other fluids that may carry radiation or other nasties that must be removed before the gas is shipped to its destination.

This “produced water” can be hazardous in its own right.

Down Pennsylvania way

Today, the biggest shale-gas development is in the Barnett Shale, around Fort Worth, Texas, site of more than 10,000 wells. But the hottest political debate concerns the Marcellus shale. The Marcellus was consolidated from mud about 390 million years ago into a fine-grained sedimentary rock that trapped methane produced during the decay of organic matter. The low-oxygen conditions protected the methane from oxidation.

The Marcellus shale lies an average of two kilometers deep, far below the groundwater that feeds home and municipal water wells. With an average thickness of about 30 meters, the Marcellus contains an estimated 295 to 2,700 trillion cubic feet of natural gas.

If 10 percent of that gas can be recovered, this amounts to one to 10 years of supply for the United States, which used 21 trillion cubic feet in 2006. ¹

Fracking has been dividing communities in the East, which has seen little of the vast energy development of the West. While some landowners and businesses profit from leases and economic activity related to gas development, others fear for the safety of their well water, streams and air.

Today, much of the concern about fracking focuses on drinking water. According to Food & Water Watch, toxic chemicals in fracking fluid can contaminate water via spills, accidents, improper disposal or poor well construction. Natural gas has entered drinking water, the group notes, during “more than 1,000 documented cases of water contamination near drilling sites around the country.”

Photo: Helen Slottje

This drill worked in Dimock, Penna.

In areas with many gas wells, groundwater pollution cannot easily be traced to a particular well, and it takes some effort to trace the pollution to gas drilling itself. But widespread groundwater pollution can also be virtually impossible to reverse.

One of the more notorious cases occurred in Dimock, a Marcellus-shale town in northeastern Pennsylvania. After drilling started in 2008, 18 private water wells became polluted with methane and other chemicals, turning dishes brown and, according to a press report, residents reported getting sick from drinking the water, or even showering under it.

On Dec. 15, 2010, Cabot Oil and Gas Corp. signed a consent agreement with the Pennsylvania Department of Environmental Protection regarding 18 polluted water wells in Dimock. Cabot agreed to suspend drilling, plug and abandon three gas wells, supply drinking water to 18 houses, test home well water, and “comply with all applicable environmental laws and regulations” when it resumed drilling and fracking in the area.

The Department concluded, but Cabot disputed, that the company had engaged in “unlawful conduct.”

Let a thousand wells bloom!

New York City continues to oppose fracking in its prized watershed in the Catskill Mountains. And fracking opponents scored a victory on Nov. 18, when the Delaware River Basin Commission declined to move forward on a decision to allow fracking in the Basin. Opponents had warned that up to 20,000 gas wells in the area would threaten water supplies for millions.

Many billions are at stake in the debate over shale gas, which ConocoPhillips expects to account for almost half of U.S. natural gas production by 2035. The petroleum giant credits shale gas for a 110 percent rise in U.S. natural gas reserves and resources between 2000 and 2009.

What is fracking?

Hydrofracturing, or fracking, is a stage of “well completion” that follows drilling. Briefly, drillers bore through the surface, insert steel casing and concrete to seal the hole against groundwater, and drill deeper into the rock, repeatedly adding pipe and cement if needed to seal the well from the surrounding rock.

As the drill approaches the gas-bearing shale, it is “steered” into a horizontal direction, then forced through the source rock for hundreds of meters or more. Once the drilling is completed, holes are punched in the lower casing and millions of gallons of frack fluid are pumped into the well at roughly 1,000 times atmospheric pressure.

After some of that frack fluid is withdrawn, production can begin, as gas rises under the influence of the immense pressure belowground. At the surface, produced water and frack fluid are removed before the gas is piped to market.

Fracking in the history books?

The gas industry often meets questions about the environmental aspects of fracking by asking, essentially, “What’s new?” “The history of fracturing technology’s safe use in America extends all the way back to the Truman administration, with more than 1.2 million wells completed via the process since 1947,” says the industry group Energy in Depth.

But fracking “was a rare process” at first, says Geoffrey Thyne of the Enhanced Oil Recovery Institute at the University of Wyoming. For 20 years it usually used water measured in the tens of thousands of gallons (not millions like today) and sometimes sand, says Thyne. But in the 1990s, drillers in Wyoming “did a giant frack. Suddenly the amount of [frack] fluid jumped 10 or 20 times, and suddenly a whole class of resources that was labeled unconventional became accessible.”

Let’s do the definitions:

Thyne notes that in contrast to conventional gas, shale gas requires “a lot more development, more wells and infrastructure, to get the same bang for the buck, and that creates a lot of friction with landowners.”

Jonah, an unconventional gas field in Wyoming “has a well on every 10 acres,” says Thyne, who teaches petroleum geology and hydrogeology. “If you flew over it, it looks like a moonscape, there’s an incredible amount of development. If you bring that into areas that have not had development, people are going to be put back on their heels: ‘What the heck?’”

As the economic benefits of fracking were proven, it became the rule for oil and gas. Over the last 20 years, Thyne says, “we went from a period where one well in 100 would be fracked, maybe one time each, to now, where 90 percent of all gas and oil wells are fracked, and the number of frackings per well has gone from one to as many as 25, done over a period of several months.”

But that growth is both normal and desirable, says Felmy. “Absolutely, it’s been a wonderful development of technology, and like all technology, it takes time to ramp up. Fortunately, [as a result] a bright spot for consumers is the low price of natural gas today.”

Let the debate begin

The impact of fracturing and horizontal drilling is evident in a new estimate from the U.S. Department of Energy, which places the national gas resource at 110 years of current consumption (although by definition not all of a fossil-fuel “resource” can be recovered).

Projections about future production are inherently debatable because the economical amount of any energy resources depends on future prices. Internal emails from the U.S. Energy Information Administration have suggested that estimates of production and profit in the shale-gas boom exhibit signs of “irrational exuberance.”

In 1996, Alan Greenspan, then chairman of the Federal Reserve, used that to describe the “dot-com market bubble.

Natural gas has environmental benefits over coal and oil, including a reduced greenhouse-warming impact. To release the same amount of heat, oil and especially coal release more carbon dioxide than methane.

We have seen an April, 2011 study claiming heavy releases of heat-trapping methane from fracking and drilling make natural gas worse than coal for the climate. Although critics have questioned the study on the ground that the massive releases are both dangerous and uneconomical, methane is clearly entering the atmosphere at some gas operations.

Ozone, which damages the lungs and triggers asthma attacks, forms when sunlight strikes hydrocarbons released from a gas or oil well. The Environmental Protection Agency is studying ozone and smog at a gas field in Wyoming.

In a tight economy, jobs and taxes are big allures of gas drilling. Some landowners have profited mightily by leasing land to gas firms. In 2009, an industry-financed study reported that 622,000 people are directly involved in the discovery, extraction and distribution of natural gas in the United States, and the industry had an estimated, direct economic impact of $170 billion.

Concerns and open questions

There are plenty of concerns about the intensified gas extraction enabled by hydro-fracturing. Beyond the worries about noise, traffic, and the “industrial landscape,” there are other concerns.

Seven hours after fracturing began, more than 50 shallow earthquakes occurred within 3.5 kilometers of a gas-drilling operation in Oklahoma, in January, 2011. According to the Oklahoma Geological Survey, “The strong correlation in time and space as well as a reasonable fit to a physical model suggest that there is a possibility these earthquakes were induced by hydraulic-fracturing,” but added that this is “impossible to say with a high degree of certainty… “

Fluid chemistry

Frack fluid, the liquid used to pressurize and crack underground rocks, is a major concern about fracking. Water, an incompressible liquid, and sand, used to hold open the fractures created by the immense pressure, are said to comprise more than 99 percent of fracking fluid. But the fluid can also contain hundreds of other chemicals to fight bacteria or rust, or to change how the water flows.

Some of the additives are common and low-toxicity, but others, like diesel fuel, are poisonous.

And many are unknown, held as trade secrets. According to an April, 2011 report from Democrats on the House Committee on Energy and Commerce, “Between 2005 and 2009, the 14 oil and gas service companies used more than 2,500 hydraulic fracturing products containing 750 chemicals and other components. Overall, these companies used 780 million gallons of hydraulic fracturing products – not including water added at the well site – between 2005 and 2009.”

The safer components of frack fluid included salt and citric acid, the Democrats wrote, but some components “were extremely toxic, such as benzene and lead.” Methanol, a hazardous air pollutant and human poison, was “the most widely used chemical … used in 342 hydraulic fracturing products.”

To counter suspicion about these chemicals, the industry recently established Frac Focus, a public database on chemicals used in particular wells. Participation is voluntary.

Wastewater disposal

Used fracking fluid needs safe disposal. “We are talking a substantial volume, millions of gallons per well,” Thyne says, “and one-half to one-third of the fracking fluid comes back, and has to be disposed of.”

Gas from many wells contains a second liquid, called “produced water,” that also needs disposal.

“In classic, conventional petroleum, they can reinject everything back into the reservoir,” says Thyne, “but they can’t do that with unconventional gas [because the rock formation is not porous], so we have a sudden surge in material that has to be treated and disposed of; that’s been a real challenge.”

Some of the liquids have been trucked to municipal wastewater plants, which are designed to remove biological waste, not the components of frack fluid.

One of those components, naturally occurring radioactivity, has sparked a flurry of interest among Pennsylvania and federal environmental regulators. The source is radium in the deep rocks; the hazard occurs if this water is released into surface water or groundwater.

Yet as so often in the fracking fracas, much remains in dispute, including whether radioactivity is elevated in rivers that receive fracking wastewater.

Contaminated water emerging from gas wells is often stored in a wastewater pit near the well site, and these pits have been linked to groundwater pollution, as EPA Administrator Lisa Jackson said in June, 2011. “It gets put in these ginormous huge pools and sits there, and that is a source of contamination all by itself, and so we need to determine how to stop that from happening.”

Wasted by the water

In some states, this wastewater can be spread on land, but a 2011 study² demonstrated that the practice can kill plants.

When 303,000 liters of fracking fluid were spread on 0.2 hectares of experimental forest, tree leaves started to brown and curl within 10 days, and 56 percent of the trees were dead within two years. Every surviving tree was harmed.

The research suggested that high levels of salts – calcium and sodium chlorides – was causing the damage. Several states, including Colorado and West Virginia, permit land application, and the test application was below West Virginia’s limits.

Industry is starting to recycle fracking fluid to reduce environmental contamination, but that’s no panacea, Thyne says. “You can recycle to a certain extent, once or twice. By that time, you’ve got to treat the water to get it back to where it was before you put in new additive. Recycling buys you a little time, but it’s not an end game.”

Mad about methane

Although industry argues that not a single case of water contamination has been conclusively attributed to fracking, methane and other contaminants are appearing in drinking water and near-surface geology after the drill-and-frack sequence.

State investigators traced a house explosion in 2007 in Geauga County, Ohio, to a faulty cementing job on a nearby gas well. After the well was fractured, gas pressure built up inside it and nearby rock formations before being released into basements. One house was seriously damaged and 19 were evacuated, but there were no injuries.

In a 2011 study ³ of 68 residential wells in Marcellus shale in Pennsylvania and New York, Robert Jackson of the Center on Global Change at Duke University found, on average, more than 17 times as much methane in wells that were located within one kilometer of a natural-gas well.

As many as 1 million Pennsylvania households rely on private wells for water, the study noted, and in general, the wells are unregulated and untested.

Jackson says the study found no evidence that fracking fluid had contaminated the water wells. “But we see the gas as a warning sign. If methane is leaking, chances are that other things are leaking too.”

The Jackson study was flawed by “a lack of baseline data,” according to Reid Porter, a spokesperson for the American Petroleum Institute. “Most critical: The authors don’t have hard data to show how much methane surfaces on its own in northeastern Pennsylvania. They cite ‘historical sources’ but don’t say how far back those sources go or exactly what the sources are. … Without more data it’s impossible to distinguish between methane emitted naturally and/or from coal mining and methane released by fracturing.”

A baseline would be nice, but the Jackson study did succeed in finding a significant elevation in methane levels closer to gas wells, and isotopic analysis traced that methane to the Marcellus shale, rather than decay of biomass at shallow levels.

Finding a way

So how is methane reaching water wells from deep shale? It could be rising thousands of feet through existing or newly stimulated cracks in the rock, Jackson says, “but the most likely explanation is poor well construction, cementing or casing.”

Petroleum expert Thyne agrees with that explanation, which “means it’s a mechanical issue that can be dealt with.”

Here, at least, API is in agreement. “The energy industry recognizes that well construction is key to community safety,” Porter wrote us. “That’s why API members have developed five documents that specifically and proactively address well construction and environmental protection practices during hydraulic fracturing.”

When API maintains that fracking groundwater has never been polluted by fracturing fluid, it cites two studies:

Industry is fond of quoting EPA administrator Jackson telling Congress that there has never been a documented case where fracking polluted drinking water, but she implied in June, 2011 that such certainty had not been possible: “There are chemicals in the frack water, and until recently, even today, companies don’t have to disclose them, and we at EPA are exempt from regulating them, except for diesel.”

Because gas wells are much deeper than shallow aquifers, Jackson said groundwater pollution can be prevented by attention to the details of drilling, casing, cementing and closing. “If you get a bad operator, someone who is not responsible, who is not seeing how important it is to get this right, they can contaminate an aquifer … so there need to be some standards.”

Is the enemy fracking, gas drilling — or neither?

The gas industry fears legislation that would ban fracking, says Felmy, and it also believes that some of the opposition comes from “anti-fossil-fuel folks who have discovered that a tenet of their opposition, that we are running out of fossil fuels, is suddenly not true. With the technology developments we have, we can produce a vast amount.”

Yet behind all the protest and controversy, there is some constructive movement. Pennsylvania passed an improved well casing standard in February, 2011, so “it’s quite possible that that will go a long way to fixing problems in newer wells,” says Jackson of Duke. New York has not decided whether or how to allow hydraulic fracturing.

In November, the U.S. EPA announced plans for a study of any relationship between hydraulic fracturing and drinking water, with initial results due in 2012. That’s in addition to ozone studies related to gas extraction.

Some changes are likely in the shale-gas industry, Thyne says. “It’s got a lot of newcomers, it’s very much a gold-rush mentality where the profit margins are low. As the industry matures, it will shake out and the big boys will tend to self-regulate both production and environmental standards.”

Oil and gas are secretive industries, and the voluntary website listing chemicals in fracking fluid is a step toward openness. “The public said, ‘If this is not a problem, why won’t you tell us?’” says Thyne. “I sometimes feel the [energy] companies treat the public a bit like children: ‘You don’t want all these details, you just want to put gas into your car.’ But when the well is in your backyard, you want that information. Half the problem will be going away if they are transparent.”

Porter, of the American Petroleum Institute, says, “Disclosure is something we are very much in favor of.”

In deep water?

Just 19 months ago, the Deepwater Horizon drilling rig exploded and sank in the Gulf of Mexico, killing 11, releasing 4.9 million barrels of crude oil, and reminding us that fossil-fuel development can go horribly wrong. Stories from the gas fields remind us that polluted groundwater is difficult or impossible to clean up, even when money is available. Houses atop polluted aquifers are difficult or impossible to sell.

And so the choice is simple: ban fracking, and accept a rising price for energy, or do gas production right, even if that takes more time.

It’s trite but true: Time is money when you are running a gas drilling rig, but haste makes waste. “The Deepwater accident happened because people were in a hurry,” says Jackson of Duke. “I think there is tremendous pressure to move drilling rigs along in the Marcellus. There aren’t enough drill rigs … . The cause of problems here is likely the same as it was with BP: haste.”

Best management practices and standards are important, says Jackson, “but people have to follow them day after day in the field, when they are in a hurry and when nobody is watching, and that does not always happen.”

– David J. Tenenbaum

Twelve years on, and another billion people are sharing the planet.

Starting half a century ago, the Green Revolution doubled or tripled production of the major grains, using modern seeds, heavy use of fertilizer and irrigation. The revolution helped India and China to feed themselves and averted widespread starvation.

Today, an estimated billion people go to bed hungry. Hundreds of millions are stunted by poor nutrition. And by 2025 another billion people will want to know what’s for dinner…

What to do?

After World War II, agronomist Norman Borlaug played a role in founding international farm research stations that invented and distributed seeds and technologies to Latin America and Asia, with a focus on the big three crops: rice, wheat and corn (maize).

The green revolution that resulted gave a dramatic boost to farm production. But population continues to rise, and funding for food projects tapered off after the initial gains were realized.

The green revolution averted massive starvation “in some situations, but in others, especially Africa, it failed terribly,” says James Lassoie, a professor of natural resources at Cornell University, and leader of Agriculture Bridge, which attempts to harmonize agriculture with conservation.

Small could be beautiful

As the green-revolution research organizations continue working on high-yield crops, a newer approach to raising food production is emerging that concentrates on methods and technologies that can be built and maintained locally.

For reasons related to economics, environment, and efficient technology transfer, the new projects have steered away from large-scale provision of food, equipment, seeds and fertilizer, and toward social and environmental goals. Many projects work in Africa, where food and population problems are most acute, and with women, who do most of the farming.

Although few would discount the role of high-yield seeds in feeding seven billion, “Economic development needs to support both environmental protection and livelihoods,” Lassoie says. “Technologies are not going to help if they don’t also deal with the social and political dynamics.”

Our look at a few of these projects only offer an educated scanning of the horizon. We neither visited these projects nor possess a crystal ball, and so can neither vouch for their results nor predict the end game. But farmers are smart people who gravitate to things that work — if they fit the local culture, economy and environment.

Enough introductory blather. Let’s take a look!

Progress on one acre in Kenya and Rwanda

Africa’s agriculture is dominated by “small-holders,” people who work an acre or two, mainly with family labor, and are an increasing focus of attention in the effort to feed ourselves.

Services are loans, not gifts, and as is common with micro-lenders, borrowers join small groups that guarantee each loan. One Acre says 99 percent of its loans are repaid.

The fund’s advisors offer farming advice during weekly visits that emphasize profitability as much as productivity. For example, because prices are usually lowest during the harvest, the advisors suggest that farmers hold on to their crops for a few months.

One Acre says its growing and marketing strategies double the average farmer’s income, allowing small-holders to pay school fees and buy land to improve family income and food security. One Acre is reaching 55,000 families in Kenya and Rwanda, and aims to enroll 150,000 families by 2013.

Fish, water and wetland in Uganda

The realization that healthy ecosystems improve water quality and store carbon from the atmosphere has spawned a system called “payment for ecosystem services.” After all, if people downstream are getting clean water or hydroelectric power from a well-forested watershed, that should be worth paying for…

It’s a simple concept that conceals any number of complexities, but these payments do bring in outside money that can support environmental improvements.

In densely populated southwestern Uganda, the organization Nature Harness Initiatives is combining payment for ecosystem services with collaborative management to protect the environment of a wetland in the Kanyabaha-Rushebeya region.

The wetland provides fish for food, bees for honey, and fiber for thatch, mats and baskets, but farming and deforestation by people trying to make a living are causing serious soil erosion, harming the wetland and its many human and non-human residents.

Although baseline data on water quality is short, Nature Harness is convinced that it’s program works, and can be expanded to regions with similar problems.

Growing new farmers in Uganda

In Uganda – and elsewhere — farming is often seen as an occupation best suited to school dropouts and people who cannot afford college. Could interesting the younger generation of Ugandans in growing vegetables reverse this trend?

Through the Project for Developing Innovations in School Cultivation, more than 1,100 children in at least 31 schools have transformed schoolyards into gardens as they learn to grow local crops with traditional and environmentally-minded methods.

Project DISC was inaugurated in 2006 to combat rising food shortages and preserve Uganda’s culinary traditions. By allowing children to experience growing, tasting and cooking fruits and vegetables, it is cultivating a generation that values agriculture and quality, local food.

(The whole setup reminds us of the U.S. urban farming movement.)

The farming lessons includes methods for sustainably growing crops in Uganda’s increasingly hostile climate, as the children learn about raised gardens, drip irrigation and drought-tolerant crops.

Project DISC does face obstacles, such as Uganda’s staggering population growth and declining soil fertility. All the more reason to encourage young Ugandans to see agriculture as a respectable livelihood, rather than a last-resort job.

Community grazing rights in Mongolia

In land-locked Mongolia, 2.7 million people coexist with about 10 times as many horses, cattle, sheep, goats and camels. The people of Mongolia have followed their animals for centuries, living a nomadic life in portable shelters called gers.

This windy, dry and cold land exists at the mercy of the weather; the harsh winter of 2010 killed 20 percent of the country’s livestock. Meanwhile, overgrazing is promoting erosion and making the pastures less productive, while the Gobi Desert encroaches from the South.

It’s a classic case of the “Tragedy of the commons,” the idea that resources owned by all are protected by none.

To avert tragedy, Mongolia is experimenting with “co-management,” a system for making joint decisions about the grasslands to maximize benefits and prevent long-term degradation. In co-management, groups of herders contract with the government to assume the regulation and protection of tracts of land. Contracts are adapted as needed during annual renegotiations.

The result has been a reduction in herd size and an attempt to breed better animals to maximize profits from a resources that is now managed with an eye to community prosperity. Evaluations say the process is raising family incomes by 5 to 10 percent annually, and the idea is catching on elsewhere in Mongolia and Central Asia.

Banking on the harvest in Niger

In many lands with poor people and marginal agriculture, the months before harvest are called the “hunger season.” In Niger, in the dry Sahel region just south of the Sahara Desert, the hunger season has been exacerbated by droughts and locusts.

Niger is second to last in the United Nations Human Development Index.

Micro-lending is catching on as a way to fight poverty, but there’s a twist in Niger: Instead of lending money, the Project for the Promotion of Local Initiative for Development in Aguie lends grain through “soudure” (pre-harvest) banks.

The cooperative buys grain from local farmers, and lends it when needed at 25 percent interest, a fraction of what moneylenders charge.

By the middle of 2010, about 168 soudure banks, managed by over 50,000 women, were storing enough millet – a local staple grain — to feed 350,000 people for at least a month. That storehouse helped villagers survive the hunger season (see #38) during the spike in global food prices in 2008.

Beating hillside erosion in Yunnan, China

After a devastating flood in 1998 in Southwest China (blamed largely on deforestation of steep slopes), a new reforestation project focused on planting trees that generate income. (Reforestation projects can drive farmers and herders from their land by planting trees that may offer long-term environmental advantages but do not provide income to local people.)

The World Agroforestry Center has sponsored a different approach to reforestation on a 42-square-kilometer watershed in Yunnan Province. The project began with a collaborative design process that focused on using trees for food, forage or other purposes.

Walnut trees provide edible nuts. Beneath the trees, medicinal herbs are planted as a cash crop. Women may spend four hours a day collecting firewood, but new fermentation devices transform pig dung into biogas for cooking.

Although the project is said to be working on the small scale, and is producing enough income so parents can send kinds to school, these techniques will only provide a meaningful benefit once they are applied more broadly.

WFARM-TV in Benin

Rice, a staple crop and food through much of southern Asia and tropical Africa, is usually grown on small farms. To stimulate and propagate farmer creativity, Africa Rice develops short videos with significant input from local farmers, and distributes them across the rice-growing region.

Farmers are inherently interested in the ideas of other farmers, and seeing their innovations legitimizes farmer experiments and leads to further improvements.

The 10- to 20-minute videos cover such topics as preparing land, transplanting seedlings, managing weeds and harvesting the rice. AfricaRice distributes the videos through farmer associations; the farmers line up the video equipment and stage the screenings, which are often held outdoors.

By 2009, 11 videos were available to communities in Africa; some have been translated into more than 30 African languages and/or been transcribed for radio broadcast.

– David J. Tenenbaum

Seven viewpoints

Introduction

Katharine Hayhoe

Richard Alley

John Nielsen-Gammon

John Williams

Michael Notaro

Kent McGregor

Kevin Trenberth

Drought and searing heat in Texas: Is this the face of global warming?

Courtesy Eric Bruning, Texas Tech University Atmospheric Science

The cold front that blew through Lubbock, Texas on Oct. 17 raised a dust storm not seen since the 1930s Dust Bowl. The dust storm, seen in this movie, is called a “haboob,” an event more common to Saudi Arabia than Texas.

On Oct. 17, a cold front blowing through Lubbock, Tex. raised a red dust cloud that recalled the awesome Dust Bowl of the 1930s, an epoch of drought, enormous dust storms, poverty and social upheaval that depopulated the Great Plains.

The 2011 dust storm served as an exclamation point on a cruel Texan summer, with drought, wildfires, and temperature records that would not quit. On Oct. 19, the Lower Colorado River Authority, source of much water in the Southwest, warned customers that the drought was likely to force another 20 percent cut in water supplies.

On Oct. 18, Texas Lt. Gov. David Dewhurst instructed the state legislature to study drought-related problems like helping homeowners protect against fire, and ensuring that utilities would get enough water to cool their generators.

As far as we could tell, the multi-pronged assignment did not mention something that many observers think contributes to heat waves, fires and droughts: climate change.

Many recent “natural” disasters have raised the same question: Is the no-sense-denying-it-any-longer human-caused planetary warming intensifying devastating hurricanes, giant rainfalls and snowfalls, or the deadly heat waves in Europe (2003) or Russia (2010)?

Despite political skepticism in the United States, the scientific study of changing climates has grown exponentially for 20 years. In 2009, almost 14,000 research reports focused on climate change, and 20 scientific journals are devoted to the issue.

UPDATED NOV. 18: Today, the New York Times reported that a United Nations panel has concluded that “At least some of the weather extremes being seen around the world are consequences of human-induced climate change and can be expected to worsen in coming decades. It is likely that greenhouse gas emissions related to human activity have already led to more record-high temperatures and fewer record lows, as well as to greater coastal flooding and possibly to more extremes of precipitation, the report said.”

Enough introductory blather. Let’s ask some experts: Is the hot, dry weather in Texas a reflection of global warming? Or is it just proof that the essence of weather is its natural variability? The Why Files talked to seven climate scientists. Peruse their viewpoints in the box above.

El Niños, the global cycles of weather that are driven by a hot spot in the tropical Pacific Ocean, have been linked to drought, storms and famine in many parts of the tropics.

Today, a study in Nature finds that deadly conflicts have started twice as often during the el Niño years – but only in the many countries affected by el Niño.

Scientific interest in el Niño mushroomed during the 1980s, when climate experts began to correlate historic cycles of anchovy harvests along the west coast of South America with changes in weather thousands of kilometers distant, and eventually unraveled a planetary cycle driven by the appearance of huge pools of warm water in the western Pacific.

Because the warming seemed to coincide with Christmas, it was called el Niño, for the Christ Child.

El Niño is now recognized as the warm-water segment of the el Niño Southern Oscillation (ENSO), which also includes a cold-water counterpart called la Nina. Now acknowledged as an engine of global climate, el Niño is linked to prolonged droughts, heat waves and crop failures.

Previous efforts to study whether weather and global warming could affect war have related past environmental changes with conflict and the decline of civilizations, says Solomon Hsiang, who completed the new study as a graduate student at the Lamont Doherty Earth Observatory at Columbia University. But the studies tended to be case-by-case, he notes, and “even if every conflict or collapse happened at random, some would occur during a period of environmental change, so this isn’t compelling evidence.”

Looking carefully

To study the issue more systematically, Hsiang and collaborators Mark Cane and Kyle Meng:

The data showed that conflicts are twice as likely to start during an el Niño, says Hsiang, and that 21 percent of overall conflicts can be attributed to el Niño. The increase was only seen in countries strongly affected by el Niño.

Surprisingly, the average changes wrought by an el Niño are quite minor, Hsiang admits – about 0.05°C rise in temperature, and about 0.1 millimeter reduction in daily rainfall.

Small is … powerful?

How could such minor changes affect warfare?

A study that correlates data does not show why they are related, but there are many ways that seemingly small effects could change human behavior, says Hsiang, who is now at Princeton University, especially considering that averages can conceal major alterations in different locations:

However, Marshall Burke, who published an influential 2009 paper ¹ that found a significant increase in warfare during hot weather in sub-Saharan Africa, noted by email that the increase in conflict was seen only inside the el Niño region, and thus, “We might conclude that these global market mechanisms are not at work.”

Still, the new study adds something to the discussion, Burke says. “The [Hsiang] paper’s main innovation is in linking historical changes in the global climate to conflict risk, whereas past studies (including ours in PNAS) looked only at the effect of local weather variations on conflict.”

Burke, a Ph.D. candidate at UC Berkeley department of agricultural and resources economics, added, “They provide very convincing evidence that ENSO-related changes in the global climate are strong drivers of conflict risk in the regions whose weather is affected by ENSO.”

Looking at limits

Mark Cane, a climate scientist at Columbia’s Lamont-Doherty Earth Observatory and a co-author of the new study, said weather does not equal destiny. “No one should take this to say that climate is our fate. Rather, this is compelling evidence that it has a measurable influence on how much people fight overall.”

Ultimately, the motivation for the new study was to peer through the keyhole of time and anticipate a warmed world, Hsiang says, but he admits that the predictive power is limited. “In relationship to global warming, we want to be careful. El Niño is very different … in terms of its spatial pattern, the changes on the ground, and the rate of change. Until we have a much better grasp of these, it’s very hard to take these results and produce any kind of projection for future climate change.”

Still, he adds, “The debate until now has been whether there is any reason to believe that a shift in climate can produce conflict.” Now, “The question is not whether it’s possible, but how much global climate will influence conflict.”

– David J. Tenenbaum

Photo: Tim Lindenbaum

American coots take wing at Thompson Lake at the Nature Conservancy’s Emiquon Preserve along the Illinois River in Lewiston, Ill.

In part I, The Why Files described the growing evidence that rivers around the world are under attack by overuse, overfishing, pollution, damming, diversion and invasive species.

Amid growing concerns about a shortage of freshwater, the damage shows up in terms of declining biodiversity and widespread ecosystem damage.

On Oct. 8, 2010, Newsweek magazine summed up what it called a “global freshwater crisis”:

As rivers are dried, dammed, polluted and fished to within an inch of their ives, environmental needs, inevitably, take second place to human water requirements. Wetlands — essential to flood control, fish and birds—are drained or diked off. Dams store water but prevent fish from spawning and inundate floodplains. Dams and levees channelize and regulate rivers so barges can travel, blocking the natural oscillation of water levels and destroying wetlands. And some water diversions are so huge that they prevent rivers from reaching the sea.

It’s a spiral of decline. Pollution, demand for freshwater and over-fertilization injure rivers, which in turns harms groundwater and freshwater on the surface. Environmental damage reduces our long-term supply of fish and freshwater, and over-use of water and related resources boomerangs back to cause environmental harm.

The use and abuse of water is all about cycles, and actions taken to help the environment can help freshwater resources, and vice versa.

Photo: Mountain Visions/NOAA

In southwest Idaho, 2,100 volunteers have helped restore rivers and wetlands to benefit migrating salmon.

Light at the end of the (water) tunnel?

As The Why Files looked around at proposals to reduce damage to rivers, we noticed that many projects are trying to bring nature back to rivers and watersheds.

Faced with a succession of floods, a few American towns have headed for higher ground. In the late 1970s, for example, Soldier’s Grove, Wis., abandoned its riverside site after repeated flooding. In May, 2010, nearby Gays Mills, also on the Kickapoo River, received a $4.4 million grant to do the same, and construction of housing and businesses has begun on higher ground.

Dams are a major source of environmental trouble on rivers, and their removal is becoming an accepted restoration tactic. Although we could not find an international number, the conservation group American Rivers says more than 600 dams have been removed in the United States during the past 50 years.

Most removed dams are small, so each removal affects only a few miles of the river. However, in 2011, a 210-foot high dam will be yanked out of the Elwha River in Washington State.

Disarming the dam! River liberation

River engineering and ecosystem alteration are a fact of life on the Mississippi River and its major tributaries, where levees hem rivers into narrow channels. Although most of the Mississippi floodplain in Wisconsin and Minnesota is in nature refuges, half of the river’s floodplain has been drained and diked in Iowa and Illinois. And according to Richard Sparks, director of research at the National Great Rivers Research and Education Center, 90 percent of the floodplain has been drained and leveed in the state of Mississippi.

Above St. Louis, the U.S. Army Corps of Engineers owns dams spaced about 20 miles apart, which it uses to control water level, essentially creating a barge canal on the iconic river.

Dams and levees have sundered the river from its floodplain, which served as a home of plant and animal biodiversity and a relief valve during spring floods. Because the Mississippi carries a heavy load of sediment, that stable water level has left a thick layer of muck in sloughs along the river.

If the water level can resume its normal undulation—rising in spring and falling in fall – the yucky-mucky can be restored to wetlands inhabited by the plants and native animals that evolved to live in that varying habitat.

Restoring these wetlands is the goal of an agreement that the Corps has negotiated with fish and wildlife agencies. The Corps is adjusting dam operation so the water level falls during summer, allowing native plants to recolonize shorelines, to the benefit of migratory waterfowl and other animals. “By adjusting the control, they are having biologically measurable effects,” says Sparks, “although it does cost a little more because the Corps has to dredge areas where sediment accumulates.”

The water level may fluctuate by just half a foot near Minneapolis, and up to three feet near St. Louis, but even this smidgeon of variation is allowing hundreds of acres of wetlands to return to some of the “reaches” between dams, Sparks says. “Sediment along the shoreline can dry out and compact during summer, so when it’s reflooded, there’s less sediment to be resuspended; it’s a cumulative effect.”

Leavening the levee! Wetland watershed

The catastrophic Mississippi River flood of 1993 — when broken levees flooded millions of acres — caused a rethinking of the role of levees in the river and its major tributaries. Still revered as essential protection for cities and farms, levees are also recognized for making floods taller and more dangerous.

Photos: NASA

Satellite view of the meeting of the Mississippi, Missouri and Illinois rivers above St. Louis, Missouri. Top: 1991 (an average year); bottom: the flood of 1993. Billions of dollars worth of development has since been built in areas that were flooded in 1993.

Because levees also divide rivers from their floodplains, some conservation groups want to convert floodplain farms back to wetlands. On the Illinois River alone, conservation organizations have bought out three agricultural levee districts, Sparks says. The goal is to reconnect these areas to the river, “and attempt to recreate a water regime that mimics a more natural flood pulse.”

At Emiquon Preserve, thousands of acres of corn and soybean are being turned into wetland, upland prairie and forest by the Nature Conservancy. Between them, the Conservancy and the U.S. Fish and Wildlife Service own about 14,000 acres on this part of the Illinois River, says Doug Blodgett, director of river conservation at the Illinois Conservancy.

Instead of removing the levee, the Conservancy has recreated wetlands by shutting down pumps that once dried the farmland behind it.

Removing the levee would expose the wetland to the disturbed hydrology of the watershed, where the water level naturally fell in summer and, as in the Mississippi, fostered plant growth and soil consolidation. Low water in late summer is no longer reliable, Blodgett says, “Because we have destroyed the upland wetlands, changed prairies into row crops, channelized streams, put in parking lots and roofs, and so the river no longer behaves naturally.”

The water flow has been so altered, Blodgett says, that some land along the Illinois is “nearly devoid of plants, especially submerged aquatics.” Simply removing the levees today “would nearly wipe out the plant community that we are trying to restore.”

Once the Army Corps builds gates in the levee, however, they will be opened when the river is behaving normally. “That would let critters move back and forth, so the plants and wildlife can return to the river,” Blodgett says.

Bald eagle over the Emiquon Preserve by Jane Ward

Restoring the natural wet-and-dry cycle to the floodplain benefits the native plants and animals that evolved to live there. for example, mussels are among the most endangered species in North America, and Blodgett notes that “The Illinois River had the most productive mussel beds in North America, and that was due to the backwaters like Emiquon.”

Emiquon is already seeing a surge in rare pumpkinseed sunfish, spotted gar, horned grebe, and American white pelican. The threatened red-spotted sunfish was recently introduced, and the Conservancy and its partners plan to rear starhead topminnow, weed shiner, emerald shiner, and iron color shiner. (We don’t know much about these fish, but don’t they have gleaming monikers?)

Attitudes about floods, levees and rivers are changing, says Sparks, who has spent decades studying big Midwestern rivers. “Today, there is a better understanding on the part of the public, decision makers and conservation organizations, of what a floodplain river is. This pulsing is normal, and flooding up to certain point is good. When you said ‘flood’ 25 years ago, the immediate reaction was, ‘How do we stop it?’”

Loving the locks! Fish rodeo in the Southeast!

Dams on the Pacific Northwest are infamous for blocking the upstream spawning journeys of salmon, but the problem is widespread. Along the Gulf of Mexico, for example, the Jim Woodruff Lock and Dam on the Apalachicola River has blocked the threatened gulf sturgeon and the Alabama shad, a prolific, base-of-the-food-chain fish.

Photo credit: Steve Herrington, The Nature Conservancy

Drink up! Researchers implant a transmitter in the stomach of an Alabama shad at Woodruff Lock and Dam. These trackers show that the Southeast’s sole fish rodeo is working.

The Alabama shad, which used to occur as north as far north as Illinois, is “taking a nosedive nationwide, barreling toward official listing as threatened or endangered,” says Steve Herrington, Nature Conservancy’s project manager for the Woodruff Dam project. The inability to reach spawning grounds is a major cause of decline.

Dynamiting the dams would be unpopular and expensive, but when conservationists in the Southeast looked to help the shad, their found solution in the lock itself. “Could we move fish like we move boats?” Herrington says.

After all, when spawning time approaches, the fish naturally swim upstream — until they slam into the dam. Would it be possible to corral those fish into the lock, lift them to Lake Seminole, and allow them to continue their upstream spawning journey?

Adapting techniques previously used to help American shad migration in Maine, Pennsylvania and South Carolina, a broad group of conservation agencies, scientists and conservationists, and the Army Corps of Engineers, devised a plan to open the lock to migrating fish.

The fish rodeo occurs twice a day during spring, the spawning season.

Photo credit: Shawn Young

Fish rodeo ahead! A water pump creates a fake waterfall that attracts fish into the lock at Jim Woodruff Lock and Dam, which impounds Lake Seminole on the Georgia-Florida border.

The key is an artificial waterfall — a fancy term for a stream of water. “These are natural cues, and this bit of splashing seems effective,” Herrington says.

A stream just below the lock attracts the fish, then the lock opens, and a second stream lures the fish further inside. After the lower door closes, the lock fills, and within about an hour, the upper door opens, releasing a new cargo of Alabama shad and gulf sturgeon into Lake Seminole, and then into two rivers that supply the lake.

After five years, the collaboration has proven that it can move fish, says Herrington. “The fish we tag are moving 100 miles, through good habitat, until they bang into the next dam” on the Flint River.

Data from the Georgia Department of Natural Resources provides “strong circumstantial evidence” that the effort is also bolstering populations of the shad and the sturgeon, Herrington adds. “They are almost certainly spawning in the Flint River due to the fish passage.”

The Why Files had to mutter that the fish rodeo sounded too good (and too cheap!) to be true, but Herrington reminded us that the fish are just doing their thing. “If you have acres and acres of good spawning habitat, which we do, then all the things we know about fish biology say this is what we would expect to see.”

Aside from buying a pump and some PVC pipe from a bigbox retailer, the only cost is to open and close the lock, Herrington says. “We are trying to be really simple; we want to keep cost down to nothing.”

Crushing concrete! Reviving an urban river

During the 1960s, Milwaukee’s Kinnickinnic River was converted to a concrete ditch, useful for flushing rainwater quickly into Lake Michigan, but with no biological value. The concrete ditch, intended for flood control, further reduced the watershed’s porosity and prevented surface water from entering the groundwater.

Courtesy Milwaukee Metropolitan Sewerage District

Milwaukee’s concrete-clogged Menomenee River is scheduled for restoration in spring, 2011. Roll mouse over image to see computer image of this location after restoration.

Impervious watersheds are closely linked to a variety of river deficits, says Thomas Chapman, an engineer with the Milwaukee Metropolitan Sewerage District (MMSD). “There are studies galore that show that the minute a watershed starts getting over just 10 percent impervious, the impacts are seen, and at 25 percent, it’s a significant impairment,” says Chapman. “Most of our urban areas already have that.”

The combination of fast runoff and slow infiltration starves groundwater and washes pollutants and abnormally warm water into Lake Michigan. Meanwhile, the concrete “river” quickly parches between rainfalls.

The sewerage district also needs to reduce runoff because storms overwhelm its treatment plants, which accept both stormwater and sewage in 10 percent of its service area, and a few times each year untreated sewage can flow into Lake Michigan during heavy storms.

Ideally, Chapman says, restoring natural processes should reduce runoff into the lake, slow the storm surge, and allow incoming wastewater to be treated.

The desire to slow runoff, speed infiltration, improve esthetics and recreation and allow natural processes to clean river water have motivated the MMSD to fund a return to more natural conditions along the Kinnickinnic and Menomenee Rivers in Milwaukee.

Contractors have started obliterating the first 1,000 feet of concrete on the Kinnickinnic, says Chapman, and 84 homes are being purchased for recycling and removal. Eventually, MMSD will remove about three miles of concrete along each river, to create a 200-foot wide stream corridor — essentially a park with esthetic and biological value. “These are paved stream with no aquatic life, with garages lined up to the edge of the concrete,” Chapman says. “They are drainage ditches, kids would float through in heavy storms, and there were some tragedies.”

Milwaukee has good experience busting concrete. In 1997, the city removed the North Avenue dam on the Milwaukee river, Chapman says. “I’ve had people tell me fly fishing along the Milwaukee river is gorgeous. Who would have thought that we would get tourist dollars because we removed a dam? You lose the perception that 1,000 feet away is a high-density urban area…”

Getting organized! Australia responds to long drought

Photo: Irene Dowdy/MDBA

A long drought in Australia has sparked interest in smarter water management.

In Australia, the driest continent, the water problem is all about shortage. But after a decade-long drought, the continent-nation has learned something about water management. In fact, when they are pressed for an example of enlightened water management, water experts often cite Southeast Australia’s Murray-Darling river basin, home to one-third of the country’s agriculture, two million people, and the only two major rivers.

Faced with a long drought and caught between thirsty cities, parched farms and drying wetlands, the basin could be the stage for a water war. Instead, it is the site of advanced water-allocation by the Murray Darling Basin Authority.

The crisis has been put to good use, says Bradley Udall, a specialist in western U.S. water resources at the University of Colorado. “Frequently a water crisis brings out some very novel, innovative solutions that prior to the crisis was politically unthinkable. All sorts of interesting opportunities arise, because lots of people want to do the right thing, and are freed from political constraints.”

The authority favors transparency and provides online access to the current storage situation in itsreservoirs.

Because surface- and ground-water are both over allocated, the authority is producing a new plan, with plenty of public input, to align demand with supply.

Like a hanging in the morning, the 10-year drought, with the accompanying wildfires and economic dislocations, have concentrated minds in Australia, Udall says. “Changes have gone on in politics, policies, infrastructure, conservation, agriculture and the economy, they have all kinds of solutions on the table that prior to the drought would have gone nowhere.”

The language used to discuss water reflects the changes, Udall says. “They use the term ‘water security’ over and over, and they use ‘security’ the way we use ‘national security.’ It’s a reflection of how seriously they take their water problems.”

As Udall indicates, nothing could be more dangerous than taking freshwater for granted. How will the rest of the planet respond to the growing freshwater shortages?

Photo: Oct. 7, 2010, friedrich glorian

With red sludge still visible, women survey the damage in Hungary. Eight died when a dike burst at a factory that processed ore into alumina, a raw material for aluminum.

Have you seen the photos of aluminum sludge surging through villages in Hungary, heading for the Danube River? With eight people dead, and new cracks appearing in the wall containing a pond-ful of alkaline sludge, we’re left to hope that the toxic crud is defanged by dilution before it does too much damage to the mighty Danube.

Still, the spill got us to thinking about the plight of the world’s rivers. Rivers are our foremost source of freshwater, used for drinking, industry and agriculture. Their wetlands and floodplains clarify water, temper floods, and provide an irreplaceable habitat for countless plants and critters, many of which are the major source of protein for hundreds of millions of people.

But a new study in the journal Nature shows that the globe’s rivers are being lambasted by pollution and invasive species. Heavy burdens of artificial fertilizer have created dead zones at the mouth of hundreds of rivers. Rivers are being over-fished, channeled into barge canals, and drained for irrigation, industry and drinking water.

Graphic: Barry Carlsen, copyright University of Wisconsin Board of Regents

A new analysis of 23 threats to global water security and biodiversity shows many regions with a high cumulative level of threats.

When the study¹ assessed river health in terms of pollution, biological change, watershed disturbance and water resource development, rivers carrying 65 percent of the total amount of water that rivers bring to the ocean “is moderately to severely threatened on a global basis,” says study co-author Peter McIntyre, a professor of zoology and freshwater expert at the University of Wisconsin-Madison.

Dam difficult

Both human water supplies and the natural world are endangered, McIntyre says. “One-quarter of the world’s vertebrate species live in fresh waters, and hundreds of thousands of plants and animals are at risk because they live in places where threats are high.” In total, biodiversity is more threatened in freshwater than it is in saltwater or on land, McIntyre says; ominous declines are being seen in fish, turtles, mussels and plants.

Lest “biodiversity” sound frivolous, estimates suggest that the value of “ecosystem services” like clean air and clean water exceeds the global economic output. The necessity of clean water is obvious, but we are also utterly reliant on plants, above and below water, to convert carbon dioxide into oxygen.

And these ecosystem services are best served by stable ecosystems.

Managing freshwater is a delicate balancing act, and some experts anticipate that tightening supplies will lead to disputes or even water wars later in the century. The U.S. government says if current trends continue, “by 2025, one-third of all humans will face severe and chronic water shortages,” with the first and worst problems appearing in Africa and the Middle East.

Already, the Colorado River in the United States, and the Yellow River in China, are so thoroughly exploited that they scarcely reach the ocean. Low flows and massive pollution plague rivers in China, India, the Middle East and Africa.

Nile denial

Photo: Bionet

The Nile River supplies virtually all water in Egypt (notice how fields cluster along the river?) and major portions in Uganda, Sudan and Ethiopia. The Nile is polluted by sewage and agricultural chemicals, and is failing to supply growing populations along its dry lower stretches with enough water for a good standard of living. With a watershed that includes parts of 11 nations, disputes over the Nile’s water could devolve into war.

Water security vs. environment: Inevitable tension?

Although pollution, invasive species and overfishing play major roles in declining freshwater biodiversity, dams and associated water diversions are a fundamental part of the tension between environment and river development.

Dams are built to store and divert water, supply hydroelectric power and prevent floods. Dams, and the locks that allow ships to traverse them, remain a keystone of river management in Western Europe and the United States, which is home to an estimated 75,000 dams.

While dam construction is largely over in Europe and North America (where some dams are even being removed), the 20th century was epic for dam building, says Bradley Udall, director of the Western Water Assessment at the University of Colorado. Udall notes that the volume of water stored behind dams has risen 350 times since 1900, to 5,000 cubic kilometers.

At the same time, Udall notes, due to such alterations as damming, draining, levees and development, “We have destroyed one-half of wetlands worldwide, which are very important for all kinds of ecological services, including water purification.” (Watch 23,000-plus large dams spread across the world.)

Chinese (river) checkers

Dam building is booming in developing countries, as an answer to floods and shortages of water and electricity. China’s Three Gorges Dam was essentially completed in 2008, after more than 1 million people were moved away from a new lake that is expected to cover 400 square miles. With a planned electrical output equal to more than 20 large nuclear plants (about 10 times greater than Niagara Falls), Three Gorges was also intended to halt disastrous flooding on the Yangtze River.

The series of dams that China is building or planning along the Yangtze and its tributaries will generate even more electricity than Three Gorges.

Yangtze River in When, China

Photo: Doris Antony

The river, shows intense pollution and human habitation in a city of about 9 million.

Dams can raise issues in any location. As Three Gorges proved, they displace riverside villages and cities and drown archeological sites. As is happening at the Glen Canyon dam in the United States, reservoirs can fill with silt, losing storage capacity and causing erosion as downstream areas are deprived of their normal silt supplies.

Dams also divert money that could be used for other purposes.

Granted, dams are a critical source of usable water, but they can also be a scourge of native plants and animals. “There is definitely a tension between human infrastructure and biodiversity conservation,” says Laurence Smith, a professor of geography at the University of California at Los Angeles, and author of a new book on environmental trends².

China is embarked on the largest water project in history, a 50-year program to move water from the Yangtze toward population centers in the drier north. Designed to move 50 cubic kilometers per year, the project aims to reduce sandstorms and water shortages while bolstering sinking aquifers in North China.

U.S. Fish and Wildlife Service

Rivers in the North, like Alaska’s Koyukuk, are far less impacted by pollution, diversion and damming.

Failing fish

Courtesy Peter B. McIntyre

A man fishes at Igamba Falls, on the Malagarasi River, Tanzania, site of a proposed hydroelectric dam. Fish are a major source of protein — and dams are a major cause of fish declines.

Altering rivers with dams enacts fundamental changes in ecosystems, says Smith. “A lot of the most biologically diverse riverine environments are seasonally flooded wetlands and flood plains. Biodiversity is not found in a big reservoir behind a dam… It is more the episodic flooding [of natural rivers] that gives this diverse habitat.”

Dams block the migration of important fish species, including the salmon, which is vanishing along the Atlantic and Pacific coasts of the United States, where dams block the upstream spawning journey.

That problem is widespread, says McIntyre. “In the tropics, species like big catfish, and the family known as the tetras, are very intensively fished. You have regions where people depend on these migratory fish, and if you put in a dam to stop the migration — rivers are aquatic highways — you profoundly change the system. There’s a real concern that if fisheries collapse, hundreds of millions of people worldwide who get a majority of their protein from freshwater fish could go hungry.”

In the central United States, massive dams and engineering projects on rivers like the Illinois, Missouri, Mississippi, Tennessee, Wisconsin and Ohio have also been blamed for ecosystem destruction.

For example, locks and dams north of St. Louis on the Mississippi stabilize the water level so large barges can traverse the river. But that stability, combined with extensive levees on the banks, has eliminated vast wetlands that once bordered the river. When the river no longer surges in the spring and subsides in the fall, remaining flat land along the river turns to muck that can no longer support native plants and animals.

Photo: Jason Sturner

Massive engineering projects along the upper Mississippi River have essentially changed the river into a barge canal.

Biodiversity black hole

One reason to foster biodiversity in rivers and watersheds is this: Biological systems with many interacting species tend to be more stable, and people, like other animals, have adapted to a fairly stable environment. “In experiments with bacteria, if you strip away species, you eventually hit a point where the basic properties change,” says zoologist Peter McIntyre. “It can be on a plateau of high function for a while, but there is a threshold, and we can’t predict where it occurs, things start to fall apart.”

The classic analogy, McIntyre says, “is popping rivets on the wing of an airplane; you pop one too many, and boom! down you go. In the global river context, we are rolling the dice, we know we are losing species. The rates of extirpation and extinction are highest in freshwater; and that is where we are seeing the worst human impacts.”

Scientists who are looking more broadly at the health of river ecosystems are hampered by a lack of information. “There are no global data sets” that would support an exact measurement on the biological health of rivers around the world, says Carmen Revenga, a freshwater scientist at the Nature Conservancy.

Still, new evaluations of biodiversity are delineating the difficulties. Revenga says a recent assessment listed 253 endemic species of freshwater fish in the Mediterranean — meaning they are found nowhere else — and 56 percent of them are threatened with extinction. Another survey found severe declines among 40 percent of the 300 species of freshwater turtles, she adds. “Nobody would have guessed it was that bad.”

The inevitable tension between environment and human water use is growing more intense in dry places such as Africa and Australia, with heavy population pressure and intense land usage.

When farms, people or industry get thirsty, “Freshwater biodiversity has not tended to play role in discussions about water security,” Revenga says. “Usually there is a lot of focus on providing water that is secure and safe. Irrigation took precedence at first, and now cities take precedence, but the ecosystem hardly gets included.”

The sad, dry Aral Sea

Photo: Gilad Rom

The Aral Sea in Central Asia dried up after the rivers that fed it were diverted to irrigate vast cotton farms.

And that leaves less water for ecological purposes, Revenga adds. “When we calculate the amount of runoff in a basin, we assume we can tap all the water that’s available” for human uses. “The conservation and environmental community has not interacted with the water supply community, and the environment is almost forgotten.”

Mono Lake in California, whose water was diverted to Los Angeles in the 1940s, is one example showing that cities and farms have come first in American water management. According to the Mono Lake Committee:

In recent decades, California has been pressured to allot some water to environmental purposes, part of a gradual rebalancing of water use in the dry, densely populated American Southwest.

We’ll explore evidence of progress in water management in the next Why Files, but note that cities like New York rely on watershed protection to ensure a clean, adequate water supply. “It’s a very good strategy to protect upland forest, and reduce siltation and runoff into streams, but a lot of projects don’t look at biodiversity in the river,” Revenga says. Watershed protection is rare, and in any case the ecological benefits are secondary to the need to provide clean water to cities, she adds.

Climate change

As more people look to rivers to supply more water, there’s one final factor to consider: the climate. Brad Udall of the University of Colorado, an expert on the waters of the West, told us that climate change is not just about temperature. “You could make a compelling argument that it’s about changes to water cycles; changes in the quantity, quality and timing, almost all of which are detrimental” to freshwater supplies.

In general, Udall says, studies of ancient climate show that “wet areas get wetter and dry areas get drier.” In the Colorado River basin, where climate change has been intensely studied, “we can expect a 10 percent to 20 percent reduction in runoff by 2050.”

Photo: Laslovarga

Hoover Dam and its reservoir Lake Mead are major factors in Western water management, but at what environmental cost?

Because so many rivers in the American West are fed by melting snow, warmer winters already have a major impact, Udall says, with the earlier spring causing earlier runoff in the rivers. Studies project that the floods could happen as much as 60 days earlier in the spring, “and we are already seeing 20-day advances, especially in lower-level snow-dominated systems, like in the Pacific Northwest.”

At the same time, river flow is likely to diminish earlier in the late summer, and the water will also be warmer, Udall says, which poses problems for life. “Many critters in the water are stressed in high temperature, which also carries less dissolved oxygen.”

Dry conditions in late summer also contribute to a longer wildfire season in the West.

Climate change may be even more catastrophic where drinking water comes from rivers sourced in melting glaciers, Udall warns. Large cities like Bogotá and Lima in South America, “could go from having a glacier upstream one day to not having it the next. The United States does not have that problem, but in the Andes, there is potential for very harsh consequences.”

The Ganges: A river or a sewer?

Photo: Daniel Bachhuber

Worshippers leave heaps of offerings alongside the Ganges river in Varanasi. It’s easy enough to hose away the dregs into the river, but that just adds more pollution to the “Mother Ganges.” Says Science Daily, the Ganges “contains untreated sewage, cremated remains, chemicals and disease-causing microbes. … Cows wade in the river. People wash their laundry in it and drink from it. … The Ganges River is a major source of disease.”
If this can happen to a sacred river…

Summary judgment

Rivers collect runoff from their watersheds, and therefore carry messages about conditions from most of the land on our planet. As the authors of the recent Nature study found, trying to assess the health of rivers around the world is not for the data-shy. Differences in economy, history, geography and culture all affect how we view rivers, and how we decide whether to use, alter or preserve them.

Photo: Steve Dewey, Utah State University, Bugwood.org

Purple loosestrife is striking, but it invades wetlands near rivers, reducing biodiversity, destroying habitat for native species, and reducing the ability to filter water.

But most “decisions” that affect rivers, like allowing them to be polluted with chemicals, topsoil or fertilizer, or building a dam to store water for the dry season, are made not with rivers in mind, but with another goal, like growing more food or getting people something to drink.

“You don’t miss your water ’til your well runs dry,” pertains to rivers as well as groundwater, says Peter McIntyre, one author of the recent global river survey. “In the industrialized world, we go home at night, turn on the faucet and get beautiful, clear water, it’s safe to drink and bathe; it poses no risk to us and our kids. Mass investments in engineering and infrastructure have granted us this water security.”

As developing countries, where people struggle to find water for faucets, farms and factories, embark on the dam-building that was so crucial to European and American water supplies, saying “don’t do what we did” seems hypocritical at best and repugnant at worst.

And yet experience shows that dams can damage or destroy plants and animals in rivers and their floodplains. We’ll concede that questions about biodiversity, the environment and the long term seldom interest people who are hungry or thirsty. But they may still be worth asking. Will a proposed dam harm an essential fishery? Will it produce benefits over the long term, or will it silt up in a decade because trees have been stripped from its watershed?

There are lessons to be learned from the water-management experience in Europe and North America, and one of the most significant one is to expect a continual tension between human water use and biodiversity. “I am not pretending there is an easy answer,” McIntyre says, “or that I should have the right to dictate to that person whether they build a dam or not.”

Coming Oct. 28: Part II : The Why Files will discuss some river-management ideas for balancing human and environmental needs.