Hunger season approaching?

In some places, the harvest is preceded by “hunger season,” when stored crops are exhausted but the new crop is not ready. For many reasons, we’re wondering if the Earth is entering a long hunger season:

Food prices reached records in February, which may even have helped spark the political unrest that swept the Middle East. As Lester Brown of the Earth Policy Institute notes, a 10 percent rise in the price of wheat barely budges the price of bread in developed countries, but directly boosts the price of chapattis in India.

The population is expected to reach about 9 billion by 2050, and 3 billion people with rising incomes have a growing appetite for grain-intensive animal protein.

The World Food Program estimates that one person in seven goes to bed hungry. One reason is poverty: In this world, only the poor are hungry. But other reasons are related to supply and demand:

The end of civilization?

Depleted soil is a legacy of many failed civilizations, wrote soil scientist David Montgomery1 of the University of Washington. “In recent decades, archaeological studies confirmed pronounced episodes of soil erosion associated with the rise and subsequent decline of civilizations in the Middle East, Greece, Rome, and Mesoamerica, as well as other regions around the globe.”

Indeed, Montgomery writes, “a limiting lifespan of an agricultural civilization can be estimated by the time needed for conventional agriculture to erode through the native stock of topsoil,” which “predicts reasonably well the historical pattern of a 500- to several-thousand-year lifespan for major civilizations around the world.” These calculations, he says, support the argument “that it was not the axe that cleared forests but the plow that followed that undermined many ancient societies.”

Soil health is often gauged by the percentage of organic matter — the decomposing plant material that feeds microbes and soil animals, and enables soil to hold water and nutrients, says Jane Johnson, a soil scientist with the U.S. Department of Agriculture in Minnesota. “Most of the characteristics that we associate with high quality soil are directly or indirectly linked to soil organic matter.”

Therefore, the emphasis on protecting and improving soil so it can feed an ever-growing population often comes down to the level of organic matter. In the United States, much of the cropland has already lost 30 to 50 percent of its organic matter since Europeans started farming a couple of centuries ago, says Rattan Lal, a professor of environment and natural resources at Ohio State University.

Most productive soil in Africa and Asia has lost 70 percent to 80 percent of its organic matter, says Lal, an outspoken defender of the soil, and long ago crossed the line toward ruination. “There is a threshold — about 1.2 percent to 2 percent of carbon [the usual measure of organic matter] — to maintain soil health, water retention and other soil services.”

Many soils in Africa, India and China have only one-tenth that much carbon, Lal says, and that leads to a truckload of trouble. “When you add fertilizer, it washes into the groundwater because the organic matter is not there, and the same goes for pesticides and herbicides. These chemicals wash into rivers or the groundwater, or enter the atmosphere, where they cause human health and environmental problems,” without conferring much benefit to the crop.

Lal says a train in his native Punjab, India is dubbed the “Cancer Express” because it travels through a region where “many people are prone to cancer because of pollution of the drinking water. The soil does not have the capacity to hold water and pollutants. That is what the biological health of soil does; you get microbial decomposition, absorption of organic matter and retention of water. If crop residues are taken away, if dung is taken away for cooking, the soil has nothing left to provide the services. It essentially becomes a sand culture.”

Good soil, great benefits…

About the only bright spot in the grim picture of soil destruction is this: many solutions offer synergistic benefits. Leaving a crop residue on the surface cuts wind and water erosion, and raises the level of organic matter. Conservation tillage cuts erosion, reduces the need for irrigation, and stores carbon in the soil. Smart irrigation reduces water use, and the need to plant on steep, erodible slopes.

Soil – some still call it dirt – is not as popular as Facebook or Dancing with the Stars. But it’s a whole lot more important. “Our ability to feed humankind in the future depends on a stable, improved soil resource,” says Jerry Hatfield, director of the Agricultural Research Service lab in Ames, Iowa.

Or, as University of Minnesota soil scientist William Larson once said, “Soil is that thin layer on the planet that stands between us and starvation.”

Enough with the problems. Let’s look at some serious soil solutions.

Washing away

Because water erosion can rapidly flush nutrients, mineral soil and organic matter from hilly land, the battle against water erosion has been a focus of American farmland conservation since the 1930s. One common prescription is contour planting; rows planted across the slope are more resistant to erosion than those running up the slope.

A standard way to protect soil is to leave crop residues in place after harvest, but bioenergy proposals often suggest that these wastes be fermented into cellulosic ethanol. The best solution depends on the situation, Johnson says. “If the land is highly erodible, we should not take residue. But if the landscape has a low erosion risk, then if we can manage it to protect organic matter by leaving enough residue in place, chances are we will have more than enough cover for erosion control. I believe it is possible to take some residue off, but not everywhere.”

The focus in protecting soil has shifted from the mineral component of soil to its organic matter, which is more sensitive, says Johnson. “In most cases, protecting the organic matter will protect against erosion, but if you only manage for erosion control, that may be not enough to retain the organic matter.”

Gone with the wind

The “Black Blizzards” of the 1930s Dust Bowl proved beyond question that wind can transport large amounts of soil to the wrong place. Could we see a rerun of the Dust Bowl? “People say we will never have a Dust Bowl again, because of the conservation practices that we put in,” says Hatfield, but the Dust Bowl also followed years of severe drought, which further stripped farm fields of cover.

Furthermore, says Hatfield, co-editor of a new book on soil management,2 many of the windbreaks planted to slow wind erosion have been removed to allow the use of large farm machinery. “What would happen if, across the Great Plains, we had three or four years with hardly any rainfall? I dare say we would not see the extent of the Dust Bowl, but would our current conservation practices be sufficient? … How much can you expect when the land is naked?”

Confronting drought

The Dust Bowl shocked Americans, but drought is a common problem that has differing consequences. Recent reports show that California’s farm industry did well during the 2007-2009 drought, mainly because large farmers had access to irrigation water. But wheat production in Southwest Kansas is now expected to fall at least 25 percent due to drought. According to Bloomberg News, the state’s wheat crop “has suffered irreversible damage from the country’s driest spring in half a century…”

In places where irrigation is impossible or inadequate, standard soil-conservation techniques, including retaining organic matter in and on the soil, can improve water retention.

ENLARGE

Cities devour farmland

The 80 million people joining the population every year require 3200 square kilometers land for shopping malls, roads, airports and housing. Cruelly, much of that growth occurs in places with productive soil, says Charles Rice, a professor of agronomy at Kansas State University, because big cities typically start out in a region with productive farms. “Chicago is a prime example; the soils in northern Illinois are some of the best in the world, but unfortunately Chicago is growing. I hate to see that valuable productive land paved, built upon. In Asia and Europe, around the world, megacities are consuming land. We need to figure this out, but nobody has.”

Salty soil is worthless soil

A bright idea: reduce tillage, save topsoil

Perhaps the largest success story in protecting soil is the no-till revolution in agriculture. Rather than turning over soil to bury weeds and crop residues, a no-till machine plants directly in the stubble, then controls weeds with herbicide. The process saves diesel fuel and also retains organic matter, says Hatfield, who observes that carbon compounds oxidize rapidly when the soil is disturbed. “We need to protect the soil from within, with more organic matter, and from the external forces, like wind and water.” Sustaining the soil, he says, “Is really about building that organic matter reservoir.”

In 2010, no- or low-till farming occupied at least 20 million hectares each in the United States, Brazil and Argentina, with significant areas in Canada and Australia.

“If you go to South America and talk to producers,” says Hatfield, “they look at conservation practices as the normal accepted practice — if you used a moldboard plow [which turns over the soil and exposes it to erosion] they would probably shoot you! In the last 20 years, they have realized what a precious resources soil is, and to maintain its viability, they have preserved the organic matter.”

But worldwide, no-till occupies only 6 or 7 percent of the 1,500 million hectares under cultivation. “You could call that a success,” says Lal. “But in the places where it is needed most desperately, Africa, Asia, those desperate farmers cannot implement no-till.”

Summing up

Optimism is not a common response to discussions of the world’s degrading soils. Lal says two to three billion hectares already are degraded, but contends that problems related to energy use, global warming and clean water also have strong ties to land degradation.

To take two examples, surface water is easily polluted when it washes off eroded land, and healthy soil stores vast amounts of carbon, slowing global warming. “All these issues are linked with one another, and soil is the common link,” says Lal. “We have the IPCC [Intergovernmental Panel on Climate Change] to address climate change … but soil is addressed by nobody, even though … we cannot address water security, energy, biofuels, global warming, without soil.”

Not to mention the daily problem of putting bread on the table…

But here’s a reason for optimism: The measures that can solve individual problems often can solve multiple problems. Conservation tillage saves water, organic matter, topsoil, even energy. Drip irrigation reduces salinity and saves water and energy. Cover crops raise fertility and reduce erosion.

And, no coincidence, all of these soil-friendly practices also increase yields.

So if you like to eat, the time to think about soil is … now.

On March 11, a catastrophic earthquake — one of the four largest in the past century — struck in the ocean east of Japan, sending a colossal tsunami against the shore. By March 21, the toll of dead and missing, mainly from the tsunami, was estimated at 22,000.

As Japan confronted what Emperor Akihito called the worst crisis since World War II, we began to hear that the six-reactor complex at the Fukushima Daiichi plant, located directly in the tsunami’s path, had lost electrical power. The emergency generators also failed, apparently due to water damage to them or their fuel supply.

As we focus on the nuclear disaster at Fukushima, we emphasize that as of now, the tsunami itself is the far larger human tragedy. But like the tsunami itself, the nuclear disaster may portend further problems in other places, and is likely to affect a trend toward greater use of nuclear power around the world.

Not cool

Immediately, the arrow of trouble aimed at the most ominous type of nuclear accident: loss of cooling. Fission — splitting of radioactive elements that powers nuclear reactors — can stop when reactor operators flip a switch to insert control rods to absorb neutrons. This stops the chain reaction — the divison of uranium atoms that releases neutrons that split other atoms and generate heat — which is the whole point of building nuclear reactors to boil water and drive turbines.

But once the fission reactions cease, decay heat continues to be released from the unstable atoms that remain after fission, and it is this heat that must be removed by a cooling system after shutdown.

Past accidents have shown that decay heat can build up in seconds; and significant damage to the fuel and potentially reactor equipment can occur within minutes. The danger of such a “meltdown” is a major reason why nuclear designers and engineers focus so much effort on cooling the reactor core.

In the beginning, there was Three Mile Island

Japan, target of the only two atomic bombs used in war, is hardly the first nation to confront a “loss of coolant” emergency at a reactor. That happened on March 28, 1979, in the United States, where Pennsylvania’s Three Mile Island (TMI) reactor #2 began a partial melt-down.

Much later, the Nuclear Regulatory Commission concluded that the accident “was caused by a combination of personnel error, design deficiencies, and component failures.” As hundreds of alarms buzzed in the control room, operators, lacking a direct measurement of the water level inside the reactor, made a bad situation worse, the reactor went at least partly dry, and a large percentage of the fuel melted.

It’s safe to say the public reaction verged on panic as a bubble of explosive hydrogen built up inside the plant and evacuations were ordered.

The slow, dangerous removal of fuel revealed massive heating and damage inside the reactor. According to the book, “TMI 25 Years Later”¹: “A large portion of the core melted and flowed into the lower vessel. Most of the core experienced temperatures of at least 1727° C, with certain parts reaching 2527°C.”

At these temperatures, the essential containment vessel can weaken and fail.

TMI, the above book concluded, neared a complete a meltdown. “No one can say for sure, but some experts say that had the accident continued for another 20 to 45 minutes, the [reactor] vessel would have heated up and the metal would have lost its strength, leading to a rupture,” preventing further cooling and allowing superheated fuel to melt through the reactor vessel and enter – and likely exit — the reactor building.

From there, it’s impossible to speculate how widely the radiation would have spread, the authors wrote, but this is what is called the China Syndrome — a runaway load of reactor fuel melting its way down into the earth. Oddly, “China Syndrome” – the movie — was released 12 days before the TMI meltdown.

TMI #2 has since undergone a major cleanup. Intact and damaged fuel has been moved to storage at Idaho National Engineering Laboratory. Reactor #1 is operating normally, and final removal of the destroyed #2 awaits the decommissioning of its companion.

According to the Nuclear Regulatory Commission: “Estimates are that the average dose to about 2 million people in the area was only about 1 millirem. To put this into context, exposure from a chest X-ray is about 6 millirem.”

Nevertheless, the alarm over TMI sent the U.S. nuclear industry into a tailspin.

 

The meltdown of TMI was the death knell for growth in American nuclear industry — the spate of plants licensed during the 1980s had all been planned or under construction by 1979. Rollover to see a comparison of present dependence on nuclear energy.

Graph 1: U.S. Nuclear Regulatory Commission. Graph 2: International Atomic Energy Association

Chernobyl – the unmitigated disaster

The Lord Voldemort of nuclear accidents started on April 26, 1986, when Chernobyl reactor #4 exploded, burned and melted down in a spectacular fire that spewed an estimated 50 tons of radioactive fuel over a swath of Eastern Europe. Unlike TMI (and the imperiled Japanese reactors) Chernobyl had no vessel to contain its fuel, and a giant fire – consuming the estimated 800 tons of graphite used to slow neutrons in the reactor — burned for more than a week as brave crews tried to damp it with sand, boron and lead.

Chernobyl was located in a part of the Soviet Union that is now in Ukraine.

The meltdown produced some of the worst radiation injuries in history, and hundreds of thousands were force-evacuated from an “exclusion zone” — roughly 30 kilometers in radius — around the smoking, radioactive hulk of #4.

Within months, the cooling reactor was hastily wrapped in a giant concrete “sarcophagus” (stone coffin) to contain further radiation. But the sarcophagus is leaking, says Leon West, a professor of mechanical engineering at the University of Arkansas, who has 40 years of experience in nuclear physics, radiation protection and nuclear engineering. “Chernobyl is still open and is still a threat to the local environment.”
“Construction has already begun on the New Safe Confinement,” says photographer Michael Foster Rothbart, who lived 12 miles from the exclusion zone between 2007 and 2009, “and although it keeps falling behind schedule, target finish date is 2013.”

Japan: Facing Three Mile Island or Chernobyl?

By March 21, 10 days after the tsunami, the owners of the Fukushima power plant reported that it had reconnected electric power to all six reactors. The disaster seems headed toward resolution, says Jeff Geuther, who manages a research reactor at Kansas State University. “My understanding is that the fuel [in the three recently operating reactors and the three spent-fuel pools at other reactors] is all under water. The radiation dose has been falling at the plant, an indication that water level has increased in the spent fuel pools.”

Although it’s not clear how much fuel has melted, Geuther says, “It’s fairly clear that the cladding [a thin sheathing on the fuel rods], at a minimum, had some damage. Iodine and cesium have been detected offsite; these are fission products that would be typically be trapped inside the cladding.”

By March 23, the utility reported that the lights were on in the control room of reactor #3, but work had not yet begun on monitoring equipment and reactor cooling pumps in the three reactors that were operating before the quake. By March 24, smoke was rising from several reactors, three plant employees were being treated for radiation exposure, and the zone of concern about radiation in drinking water had been expanded. The local populace remains under evacuation.

Near-term progress in stabilizing the Fukushima plant will be measured by

A near miss?

Two positive factors helped what looks like a near-miss at Fukushima. First, those reactors (unlike Chernobyl) had thick steel containment vessels, which, despite some reports of damage, seemed to hold up reasonably well.

Second, also unlike Chernobyl, Fukushima used water, not combustible graphite, to slow neutrons.

On the other hand, Fukushima faced systemic difficulties due to the precipitating natural disasters: After the epochal earthquake-towering tsunami sequence shut the reactors down, the electric grid died, killing the emergency cooling pumps.

Then the emergency diesel generators failed, and without cooling, the reactors quickly overheated. But with roads out and the nation tending to survivors and victims of the tsunami, the nuclear emergency festered for days, through a series of explosions, fires, bursts of radiation, and evacuations of plant workers.

At one point, just 50 workers were on hand to deal with multiple emergencies at several reactors and pools of spent fuel. The desperation was on display when helicopters tried to dump buckets of water into the fuel pools and fire trucks sprayed cooling water through explosion-blasted walls.

How many broken reactors?

Despite early fears that Fukushima was mimicking Chernobyl, it seems rather to be headed toward the less malignant TMI precedent, says West. “A big leak [like Fukushima] is not like the open-air nuclear bonfire of Chernobyl that spewed radioactive materials into the upper atmosphere. The extent of the release of radiation and the continuing difficulties with cooling of reactors and spent fuel has clearly put the Daiichi site at the TMI stage.”

As radioactive particles cross the Pacific on the jet streams, “California, Oregon, and Washington should start reporting measurable traces of radioactive materials in air samples,” says West, “but for the United States, this should be more like a Chinese test of a nuclear weapon and of no health consequence.”

Radiation has already been detected on milk and green vegetables near the reactor, and now in drinking water in Tokyo. “The Japanese will need to monitor and control agriculture products to minimize the risk to public health,” says West. “This will be similar to efforts in the United States during the 1950′s, when the U.S. was detonating nuclear weapons in Nevada,” and farmers were prohibited from selling milk for four days afterwards.

Japanese meltdowns, American reverbs

As Japan evacuated neighbors from the Fukushima plant, the U.S. Nuclear Regulatory Commission (NRC) advised American citizens in Japan to move at least 50 miles away. That’s much further than specified American evacuation plans, notes Vicki Bier, a professor of industrial engineering at the University of Wisconsin-Madison. “If the NRC is concerned up to 50 miles in Japan, that certainly calls into question emergency planning here, which is limited to 10 miles.”

On March 16, California Senators Barbara Boxer and Dianne Feinstein asked the NRC to review safety at two California plants located near earthquake faults. “Roughly 424,000 live within 50 miles of the Diablo Canyon and 7.4 million live within 50 miles of San Onofre Nuclear Generating Station,” the senators wrote.

And on Mar. 22, the Nuclear Regulatory Commission agreed to accelerate a safety review at Indian Point, a pair of reactors 30 miles from Manhattan.

Japan: How prepared, in reality?

How did such severe nuclear troubles arise in Japan, where “tsunami” was coined, and which is the world’s leader in earthquake engineering and disaster preparedness?

For starters, the tsunami was much bigger than expected. But we’ve also learned from the Associated Press (on March 24) that Japanese preparations focused on natural disasters.

Was the nuclear emergency made worse because six reactors were at one location? As we saw, radiation vented from one reactor caused the flight of workers trying to tame other reactors. But multiple siting had “always been considered to be a really good idea,” says West. “You have a collection of focused professionals with lots of resources [for example, to fight fires], so if one reactor has difficulties, you could take those excess resources and focus on that situation. … This is the first situation, where [multiple sitings] appears to need to be reexamined.”

Early reports point to a critical design failure at Fukushima, says Bier, an expert on risk assessment at nuclear plants. “They were designing for earthquake and tsunami, but not for this level of damage; you’ve got to give engineers some criteria; they can’t design for anything. They could have designed for what did happen, but they apparently decided it was too unlikely.”

Design: Where are the goalposts?

A specific weakness concerned the emergency diesel generators needed to run the pumps, which apparently were swamped by the tsunami, says Bier. “There is a lot we won’t know for months, but there is reasonable speculation about things that could be done differently at modest cost. You can’t prepare for every eventuality, but probably it would have been possible to get better protection for the diesels in a bunker or on higher ground.”

The systematic disruption and near chaos interfered with tasks like avoiding melt-downs in the pools holding spent fuel, which lack the containment usually found on reactors. As Fukushima proved, accidents can be made worse as effects are compounded: the real-life scenario included a combination of a Japan-record earthquake, massive tsunami damage, regional blackouts and radiation releases.

“The surrounding area was so damaged by earthquake and tsunami that it impeded the emergency response,” says Bier. “We have seen stories about people within the evacuation zone who could not evacuate because the roads are impassable or buildings have collapsed, and they were not sending in rescue teams because the radiation was too high. Certainly it was not anticipated that the damage would be this severe, or the radiation would be too severe to evacuate.”

 

Photo: Japan Red Cross Society

Thousands of Japanese have been evacuated from around the Fukushima Daiichi reactors; masks retard the spread of disease in close quarters. Few experts expect the need for a permanent exclusion zone, like the one in Chernobyl, around Fukushima.

Fukushima: End game

Will the six reactors at Fukushima Daiichi be dismantled, like TMI #2, or wind up inside a Chernobyl-style concrete coffin?

The three reactors that got emergency cooling with sea water are likely finished due to corrosion, not to mention possible explosion damage. “Salt water is a killer,” says Robert Rosner, professor of astronomy, astrophysics and physics at the University of Chicago. Rosner expects these reactors to be taken apart and trucked to long-term storage.

Although the age of the reactors – about 40 years – militates against spending large sums on refurbishment and updating, Japan now faces an electricity shortage, so Rosner expects one or two of the plants to return to service, at least for a while.

West, however, suggests that at least one reactor may wind up encased in concrete. “If I were an engineering manager, I would be looking at the possibility of stabilizing it to deal with all the issues” and then build an outer containment to isolate the reactor but allow service visits.

Credibility at stake

Assessing the long-term impact of Fukushima requires us to look at the technology’s unique place in the popular eye. Whether the nuclear industry likes it or not, nuclear carries plenty of emotional baggage. Nuclear physics produced the mushroom clouds over Hiroshima and Nagasaki long before it was used to make electricity. And because ionizing radiation is invisible, it’s a case where what you don’t know can hurt you.

Nuclear energy also arouses fear because power-plant neighbors cannot control it, says Nathan Hultman, an assistant professor of public policy at the University of Maryland. “A lot of research has looked at why people view risks differently, and both dread and the degree of control in nuclear are nerves that are touched very strongly. We feel safer driving cars than in an airplane, even though statistically, airplanes are much safer, because we feel in control in a car.”

 

Photos: TMI, Cherobyl:Wanrouter.

While TMI today shows the scars of its accident (reactor #2 on left melted down in 1979), Chernobyl’s gravesite (rollover) evokes a much bleaker history and deeper wounds. The thrown-together concrete enclosure may need to be replaced – a hazardous, expensive task.

The Japanese nuclear industry also faces credibility problems, Hultman notes.

“Small nuclear accidents were covered up,” says Hultman. “Often the initial reaction was ‘Everything is just fine, the situation is normal,’ then it came out there was a deeper problem. Now we are in a situation where very bad things are happening, and people are not sure what to believe.”

Hultman adds that these issues are a likely fixture in the coming debate over nuclear power. “Nuclear is not the only way to boil water to generate electricity,” he says, and the discussion of energy sources must be broader than that. “Rather than say, ‘We must have nuclear,’ we need to talk about alternatives as well.”

The Fukushima debacle could further polarize a nuclear debate that was altered by both TMI and Chernobyl, says Hultman. “There is almost a religious division. People who believe it’s good think it will be the answer to all our problems, and people who don’t like it, really really don’t like it.”

An omen for the future?

The Fukushima disaster carries striking ironies. Japan was the only country at the receiving end of atomic bombs, and studies of survivors at Hiroshima and Nagasaki have been the basis for understanding the health effects of low-level radiation.

Historically, the Fukushima disaster occurred as nuclear was gaining so much traction as a low-carbon solution to global warming that some prominent environmentalists had begun to talk nuclear. “This is going to have a big effect on the rebound toward nuclear,” says West, who adds, “We just can’t burn our forests — and coal is an old forest — forever,” due to global warming.

Even technological disasters that loom large in the short run may eventually be seen as lessons, West says. “The crash of a major aircraft … does not mean that air travel should end, it means we need to tighten up our design.”

Rosner, however, suggests that nuclear, with its potential for widespread, long-term contamination, needs to live by different rules. “When you are engineering something where the consequences, if something goes wrong, are devastating, even though the probability is very small, you need to engineer to avoid the devastation. We’ve known how to do that for 50 years, but it was always just a bit too expensive on the front end, so the decision was made: The probability is so low, we are not going to worry about it.”

The “tragedy of the commons” is an old problem in ecology: if all the villagers can graze their cows on the village commons, they are likely destroy it by over-grazing.

Ironically, maximizing individual income harms everybody in the long run. Fisheries and irrigation supplies are also prone to the tragedy of the commons, and that raises a question: What conditions are most likely to prevent the tragedy and maximize production?

For a new study, Marco Janssen, a assistant professor of human evolution and social change at Arizona State University, and colleagues built a video game designed to mimic a natural productive system.

In nature, plants and animals can reproduce to fill “ecological niches” – but only if the niches are open and close to existing plants and animals. The same rules pertained in the game: tokens “grow” the fastest when open squares touch several occupied squares.

Rules of the road

In an experiment on resource use, green stars (tokens) represent resources; the circles represent the players. Tokens grow fastest in cells with four occupied neighbors. Tokens cannot "grow" in occupied cells, or in cells lacking neighboring tokens. Players use arrow keys to move; the space bar captures a token. | Courtesy Science/AAAS

To determine what circumstances would allow the players to capture the most tokens and get the highest return, the researchers varied the rules governing player behavior. In some trials, players could communicate with each other via text message. In other trials, players could punish others who misbehaved by charging them one token. In some trials, players could both communicate and punish; in other trials they could do neither.

Without changing the rules controlling token growth, the researchers then measured how much of the resource the players could capture during six, four-minute trials with different rules on player behavior.

Simply vacuuming up all the tokens as fast as possible produced the smallest harvests, because there was no place for new tokens to grow. Yet in the absence of communication, vacuuming was the ideal strategy for each player, even though they all participated in a tragedy of the commons.

Click here to view the embedded video.

Let’s talk!

When the participants could communicate before each trial, they often discussed strategy. “Typically they decided, ‘We should not harvest immediately, we should let the resource grow a little bit,’” Janssen says. “Most groups decided to split the resource into individual areas, and, 30 seconds before the end, to take as much as they could; it’s best for earnings to end up with nothing on the board.”

Click here to view the embedded video.

The most productive strategies all involved communication, which helped the players “understand the setting better, develop a group feeling, and develop some rules,” Janssen says. “I hope this will stimulate people to look at what make communications effective. There has not been much study on that” in research on using resources.

Punishment, typically used to retaliate for misbehavior, caused mistrust and reduced both cooperation and total harvest. But punishment was tricky, even when combined with communication, Janssen found. “It might be good to have communication with an option to punish, but if you actually use punishment, it may reduce mutual trust. But if you cannot use the stick, people may not cooperate. You have to be very careful when you use force.”