Sunday, May 24, 2009

Food

"I believe that the great Creator has put ores and oil on this earth to give us a breathing spell. As we exhaust them, we must be prepared to fall back on our farms, which is God's true storehouse and can never be exhausted. We can learn to synthesize material for every human need from things that grow." — George Washington Carver

Most people are unaware of the radical changes in food production since WWII. One hundred years ago most people lived and worked on farms; today most people do not, and many have never even been on a farm. We have changed from an agrarian society to an industrial society. As a result, most people think that food is produced the same way it was 100 years ago. I personally knew that there were significant changes, but reading Michael Pollans’ book “The Omnivore’s Dilemma” [1] was a revelation to me, and as I’ve read more I’ve continued to be amazed and sometimes appalled at current food production practices in the U.S..

The changes began with the Green Revolution in the middle of the 20th century. Through the use of irrigation, chemical fertilizers, new varieties of crops, use of new pesticides and herbicides, and industrialized systems, factory farms were able to greatly increase the grain yield (amount harvested per unit acre). This industrial system of agriculture is unsustainable. It relies on energy from a non-renewable resource, oil [2]. On average, it now takes ~10 calories of fossil-fuel energy to produce 1 calorie of food energy. In the process, oil-derived fertilizers and toxic pesticides and herbicides are used, and CO2 is emitted, in great quantities. Massive scale farming also began the era of perverse subsidies, perverse because they are harmful both to the environment and to the economy. Examples include paying farmers to overproduce crops such as corn and to leave fields bare during growing seasons, which can cause erosion and soil depletion, instead of employing crop rotation. Intensive agriculture also requires more water, and has led to the overuse of groundwater and falling water tables. Also, the standardization of crop strains during the green revolution has resulted in decreased natural and agricultural biodiversity. With less biodiversity, the food supply is at a greater risk to pathogens. In sum, the green revolution led to an energy-intensive, monoculture style of farming that is worse for the environment and produces food that is less healthy. You can also argue that it allowed for an expansion of the population, which allowed for an even greater negative impact on the environment. And as the growth in yield slowed, it was overtaken by the increase in population, so by 1985 the per capita production of crops began to decline, and grain reserves began to decrease [3].

Further changes began in 1973, when Secretary of the Interior Earl Butz made monumental changes in the way federal government dealt with farmers. Prior to 1973 the government paid farmers to let practice crop rotation (i.e., let soil lie fallow), generally by planting legumes every fourth year to replenish critical nutrients such as nitrogen in the soil (http://en.wikipedia.org/wiki/Crop_rotation). For example, soybeans are commonly rotated with corn so that the nitrogen-fixing bacteria in soybean roots can replace the nitrate extracted from the soil by corn. By controlling the amount of food produced, the government stabilized food prices and kept grain prices high enough to keep agriculture profitable. Butz thought it was wasteful to pay farmers to not plant the primary crop, usually cereals such as corn and wheat, especially when we could replace soil nitrogen using industrial chemicals produced from oil, so he changed the farm program. The emphasis was now on increased quantity rather than quality. Americans wanted cheap food, and large surpluses of grains like corn kept prices so low that the government had to start subsidizing grain farmers to keep them in business.

To increase efficiency, farms grew in size, and most family farms went under or were purchased by corporate farms. New corn hybrids were bred to withstand higher planting densities and tolerate the application of herbicides; the goal was to maximize the number of food calories produced per acre of land. But most of the corn grown today is less nutritious because it was bred for increased starch (larger endosperm), which results in a lower proportion of protein (smaller germ). And it is practically inedible for humans; farmers rarely eat the food they grow today.

Soon the corn surpluses became so large that new markets had to be developed. It was found that beef could be made more cheaply by force-feeding corn to cattle in Confined Animal Feeding Operations (CAFO’s) rather than letting cattle graze on grass. Americans preferred the marbled, higher fat content beef that was produced: Grass-fed beef has 1.3% saturated fat, while CAFO cows have 8% fat because they are confined to small areas and do not get any exercise. Because cows did not evolve to eat corn, their bodies are unable to digest it properly. After about five months of eating corn, cows usually develop acidosis, where excess stomach acids eat through the stomach lining and produce ulcers. To combat the effects of acidosis, livestock consume 70% of the antibiotics used in the U.S.. Because of problems related to a corn diet, cows are usually killed after living only 140-150 days; it’s unlikely they would live much longer if allowed to. The cows often have trouble walking to the slaughterhouse because they never develop the necessary muscles. It’s sadly pathetic to see a cow flopping on the ground, unable to walk toward its’ own death.

But we still had too much corn. Why not use corn as a sweetener? Americans have a sweet tooth, but the price of sugar from sugar cane was high, and Americans like cheap food. So in the 1970's food companies replaced sugar with High fructose corn syrup (HFCS). Since 1970 the average number of calories from sweeteners in the American diet has increased 30% [4]. Much of that comes from drinking soda pop, which used to contain sugar but now contains HFCS. If you read ingredient labels, you know that most of the processed foods you eat contain HFCS. Some, like pancake (not maple) syrup, are almost entirely HFCS. For our ancestors wheat was the dominant grain crop, but for us it is corn. Corn is now so widespread in our diet that is reflected in the carbon isotope composition of our hair. As a grass, corn uses a process called C4 photosynthesis that produces C with a higher 13C/12C ratio than non-grasses like wheat that use C3 photosynthesis and have lower 13C/12C. The hair of Americans typically has 13C/12C even higher than that of Mexicans, suggesting that we eat more corn than the true “People of the Corn” (corn originated in southern Mexico). We now eat and drink corn, and the animals we eat ate corn, so almost all of the food we take in is derived from corn.

But still we have too much corn. Why not use corn as a fuel? We could cut subsidies and thereby stop encouraging the overproduction of corn, but that would be politically unpopular: stop giving money to our farmers? Again, voters have a quaint, outdated image of the American farmer and his family, when in reality most farms today are owned by corporations. So President Bush had a great idea that would prop up the ebbing popularity if his political party: pay farmers to grow fuel. When this decision was made in 2007, the price of oil was on the increase. When it reaches a certain level, corn becomes more valuable as a fuel than as a food. So farmers started to sell their corn for use in the production of ethanol, and Americans felt good because when they gassed up their flex-cars they were helping Americas’ farmers and decreasing pollution. However, there is one fatal flaw in logic that you may have deduced. A huge amount of oil is used to produce that corn, so in reality you are not using any less oil to fuel your car even if you use 100% ethanol; you are simply paying Americas’ farmers to grow more corn that we don’t need. Today roughly 50% of corn today goes to feedlots; 32% is exported or turned into ethanol; and the rest is turned into corn sweetener (high fructose corn syrup).

1. Pollan, M., The Omnivore's Dilemma: A Natural History of Four Meals. 2007.

2. Manning, R., The Oil We Eat: Tracing the Food Chain Back to Iraq, in Harper's Magazine. 2004

3. Wilson, E.O., Consilience: The Unity of Knowledge. 1998, New York, NY: Vintage Books. 367.

4. Woolf, A., King Corn. 2007

Wednesday, May 20, 2009

The Nuclear Waste Disposal Problem

What, then, are our options for disposing of nuclear waste? Since our focus is on evaluating fission reactors as a viable source of energy in the future, we will examine the properties of and disposal options for SNF, and ignore storage of defense waste (from decommissioned nuclear warheads, etc.).

One option that nuclear proponents discuss is the use of breeder reactors to recycle the waste. On the surface, recycling sounds like a good choice from an environmental standpoint, as it would reduce the amount of waste that needs to be disposed of, and it would reduce the required amount of environmentally harmful Uranium mining. However, the Carter administration chose in 1977 to ban the use of breeder reactors due to the enhanced risk of nuclear proliferation (breeder reactors produce Plutonium, which is ideal for making nuclear bombs). France uses breeder reactors to recycle their fuel, but I’ve been told by experts at Vanderbilt that breeder reactors are so complex that they frequently break down and have poor safety records [1]), so France has started to decommission their plants. Breeder reactors are not a panacea to the waste disposal problem.

Geological storage is widely considered to be the safest method for storage of SNF [2]. Until recently, the goal was to isolate SNF from the surface environment for at least 10,000 years, which was considered long enough for the total radiation level to decrease to acceptable levels. However, a court ruling in 2006 (?) increased the mandatory safe storage duration to 1,000,000 years. Considering humans have yet to build any structure that has lasted more than 5,000 years, there clearly is no way to guarantee that a HLNW disposal structure could maintain its integrity and confine the waste for one million years.

Yucca Mountain is a logical choice to store SNF because it is so dry. The primary objective of SNF storage is to keep the waste away from water. Why? Because water is the strongest known solvent, and it is mobile. The fear is that water would dissolve the waste and transport it a densely populated area such as Las Vegas, which is where groundwater from Yucca Mountain was originally thought to flow. Yucca Mountain has the lowest water table in the continental U.S.; to get well water there, you would have to drill a well 2,000 feet deep. The idea was to bury the waste 1,000 feet deep so that 1,000 feet of rock would protect it from the groundwater below and any infrequent precipitation events at the surface. Furthermore, it was discovered that Yucca Mountain is in an isolated hydrologic basin, so even in the worst-case scenario where the waste contaminated the groundwater, it would still be isolated within that small, uninhabited basin. Yucca Mountain is located at the edge of the Nevada Test Site, where 928 atomic bombs were detonated between 1951 and 1992, so it is already contaminated by radiation. Finally, the low population density and suitable host rock (volcanic tuff) make Yucca Mountain well suited for disposal of SNF.

Evidence that geological storage of SNF is relatively safe comes from natural analogues such as the Oklo natural reactor in Gabon. In this location 1.7 billion years ago a natural uranium ore deposit formed. At that time natural uranium had a higher proportion of 235U, the fissile isotope, so the uranium did not have to be artificially enriched like today to generate a self-sustaining nuclear reaction. Isotopic analyses show that the ore body is highly depleted in 235U, and has the same proportions of isotopes as SNF, so we infer that the ore body acted as a natural fission reactor (http://www.ocrwm.doe.gov/fact/Oklo_Natural_Nuclear_Reactors.shtml). In fact, 15 separate reactors have been discovered at the site. When the reactors were active 1.7 BYBP, groundwater acted as neutron moderator, slowing neutrons so that they could fission 235U nuclei. The heat released by fission reactions caused the groundwater to boil off, which shut down the chain reaction. Groundwater would then fill up the reactor again, and the cycle repeated. The fission reactions consumed 6 tons of 235U, producing 15,000 megawatt-years of energy over 500,000 years and heating rocks to ~400°C. Yet in the 1.7 BY since the reactors stopped operating, the original uranium and all of the fission-product nuclides have remained immobile, even though the host rocks are permeable and were likely often filled with flowing water. This is very strong evidence that SNF can be stored safely underground.

Some of my own research can be applied to the problem of safe SNF storage. To answer the question of what material can safely immobilize the components of SNF, geologists look to nature for the answers. They look for minerals that can hold high concentrations of radioactive elements like uranium and thorium for long periods of time. The mineral that holds the longevity record, the Methuselah of all Earth materials, is zircon (ZrSiO4). The oldest solid material ever found on the surface of the earth is a 4.4 BY old fragment of a zircon crystal. How do we know it is 4.4 BY old? Zircon concentrates uranium in its structure, and once a zircon crystal grows it traps the uranium so that it can’t escape. Over time, the uranium decays to lead at a very low but constant rate, so that today we can measure the proportions of uranium and lead isotopes and estimate the amount of time elapsed since crystallization. This “isotopic clock” works because zircon also traps the lead after it forms from uranium decay, and because zircon does not incorporate any lead when it forms. Zircon can last 4.4 BY because it is very stable and therefore insoluble in natural waters, as shown by measurements made by myself and others. All of this suggests that zircon would be a good “wasteform” for storage of uranium in SNF. The problem is that zircon actually incorporates < 1 wt.% uranium in it structure, and we need something that can incorporate much higher concentrations. Another problem is that over time high radiation levels destroy the zircon structure [3], turning the zircon crystals into glass, which is much more soluble in natural waters and therefore much less effective at immobilizing the uranium [4].

A better candidate for storage of uranium and thorium is the mineral monazite, which is a rare earth element phosphate (REEPO4). Although the geological evidence suggests that monazite is not quite as durable as zircon, it can hold much higher concentrations of Th (up to 10 wt.% ThO2) without experiencing significant radiation damage and still last for billions of years. In the laboratory, I have studied the solubility of monazite in natural waters at elevated temperatures and pressures, and found its solubility to be very low at near-neutral pH. In field studies, I have investigated the stability of monazite in rocks, and have developed methods for using monazite to date the infiltration of water into rocks [5]. Although this research was “pure science” because the primary objective was to develop a better understanding of how the Earth works, it has implications for storage of SNF. History shows that most technological advances were enabled by research in pure science, and since it is primarily advances in technology that fuel the economic engine, particularly in the U.S., and that in the future may provide answers to how our society may become sustainable, it would be unwise for the U.S. to stop investing in pure science.

I am confident that further research into durability of crystalline wasteforms and the geology of potential waste disposal sites will give us the technological ability to safely dispose of SNF in the future. However, we do not and may never have the political or societal will to deal with the problem. Even if we as a society face the situation, agree on a site, and fund the building of a facility, it will take too long to make nuclear power a short-term fix to our energy needs. Abandoning Yucca Mt. means that we won't have a SNF disposal site for at least 20 years. Given the possibility that they will be stuck with more SNF in the future, utility companies are less likely to start building new power plants. In addition, since it takes about 20 years to build a new reactor, U.S. capacity to generate electricity through nuclear fission is unlikely to increase for at least 30 years.

To sum up, what are the advantages of nuclear power plants? They have near-zero CO2 and pollutant emissions. What are the disadvantages? Radiation is released to the environment at every stage of the nuclear fuel cycle. There is a very small but real risk of nuclear reactor accidents (e.g., Chernobyl). Terrorists or hostile countries could steal enriched uranium destined for fission reactors or plutonium from breeder reactors to make nuclear bombs. The U.S. has no safe SNF disposal facilities, and won’t have any for at least twenty more years. We have a limited supply of minable uranium, so nuclear power is a non-renewable energy source (we have enough U ore to deploy 1000 new reactors in the next 50 years and maintain for 40 years [6]). Finally, nuclear power is not cost-effective. In a nutshell, nuclear power is a very complicated, expensive, centralized form of energy production that requires a lot of government involvement (regulation and oversight), has a very vocal opposition, and big potential problems, while decentralized, renewable energy sources pose fewer risks and may be more cost effective.

In general, I am advocating a move from centralized to decentralized, from hard path to soft path, from non-renewable to renewable, and from fossil fuels to alternative energy sources. Nuclear is centralized, and we don't have a solution to the waste problem, so I am not recommending it as an energy source, unless it is the only way we can eliminate fossil fuels.

1. Charman, K., Brave Nuclear World? Part II. World Watch Magazine, 2006: p. 12-18.

2. Macfarlane, A.M. and R.C. Ewing, eds. Uncertainty Underground: Yucca Mountain and the Nation's High-Level Nuclear Waste. 2006, The MIT Press: Cambridge, Massachusetts. 431.

3. Farnan, I., H. Cho, and W.J. Weber, Quantification of actinide [agr]-radiation damage in minerals and ceramics. Nature, 2007. 445(7124): p. 190-193. http://dx.doi.org/10.1038/nature05425

http://www.nature.com/nature/journal/v445/n7124/suppinfo/nature05425_S1.html

4. Grambow, B., Nuclear Waste Glasses - How Durable? Elements, 2006. 2: p. 357-364.

5. Ayers, J.C., et al., In situ oxygen isotope analysis of monazite as a monitor of fluid infiltration during contact metamorphism: Birch Creek Pluton aureole, White Mountains, eastern California. Geology, 2006. 34(8): p. 653-656. http://geology.geoscienceworld.org/cgi/content/abstract/34/8/653

6. Ansolabehere, S.e.a., The Future of Nuclear Power: An Interdiscplinary MIT Study. 2003, Massachusetts Institute of Technology. p. ix-x, 1-16.

Tuesday, May 19, 2009

Why Not Nuclear?

Nuclear power has always been controversial. The fear of nuclear power plants is usually irrational, but the danger posed by nuclear waste is real. Unlike most environmentalists, for most of my life I have been pro-nuclear. Nuclear power plants produce about 20% of electricity in the U.S. [1] (15% globally), but that number has not increased since the 1980’s. Three obstacles prevented growth of nuclear power in the U.S.. First, a large part of the public resists expansion of nuclear power because they fear all things nuclear. Nuclear power will always be associated in people’s minds with the use of nuclear bombs in WWII and the fear associated with proliferation of nuclear warheads during the Cold War. Furthermore, radioactivity is particularly frightening to people because it is invisible and outside of their normal experience. Fear makes people irrational, and as a result, I have never been able to convince any opponents that nuclear power is safer than other forms of energy, even though I have the statistics to prove it (see section on “Risk”). In the U.S. the only significant nuclear power plant accident ever was the Three Mile Island accident in central Pennsylvania in 1979, a minor accident that released very little radioactivity into the environment. Both Three Mile Island and the more serious accident in Chernobyl, USSR resulted not from technology problems but human error. Despite the fear it invokes, nuclear power has a remarkable safety record. Second, electricity generated using nuclear fission reactors is more expensive than electricity produced using natural gas or coal. Finally, we have no site to store the radioactive Spent Nuclear Fuel (SNF) from fission reactors. For these reasons, no electric utility companies have applied to the Nuclear Regulatory Commission for a license to operate a new nuclear power plant in over 20 years. However, the recent recognition of the need to reduce CO2 emissions has reopened the debate: should we expand the use of nuclear power in the U.S.? Nuclear reactors do not emit CO2 or any other pollutants, giving them a decided advantage over fossil fuel-powered plants. Moreover, if we start to tax energy produced by burning fossil fuels, then nuclear power may become economically competitive. President Obama's proposed cap and trade program to reduce CO2 emissions would internalize the social cost of carbon emissions, increase the cost of fossil fuels, and make nuclear energy more economically feasible. That would leave only one problem: Can the U.S. choose a site and build a facility for storage of SNF? And if the cost of waste disposal is factored in, would nuclear energy still be cost-effective?

I think the answer to both questions is no. After the federal government spent $13.5 Billion dollars developing a high-level nuclear waste disposal site at Yucca Mountain, about 100 miles northwest of Las Vegas, Nevada, newly elected President Obama announced that the government was abandoning the project (http://www.nevadaappeal.com/article/20090306/NEWS/903069981/1070). When the President’s science advisor was asked why, after waffling for several minutes he finally said, “We can do a better job.” Considering that our country spent over 30 years developing the Yucca Mountain site, and that 30 years later it will be even harder to find a site that is acceptable to all parties (the NIMBY syndrome), I am not holding my breath. The Yucca Mountain project fell victim to politics. Senate majority leader Harry Reid represents southern Nevada, where resistance to the Yucca Mt. project has always been strong, and he had previously vowed to kill the project. This is an example of how some individuals gain too much power and abuse it by appeasing narrow interests and disregarding the greater good. Perhaps Harry Reid thought that it was his duty to do what his constituents asked (though I doubt it), but the same will happen with every state that is chosen in the future, making it almost impossible to build a facility. Nevadans named the 1982 Nuclear Waste Policy Act that named Yucca Mountain as the nation’s waste disposal site the “Screw Nevada Bill”, but now < 1% of the population got what they wanted and screwed the rest of the country.

I know many people who are still asking, “why not nuclear power”? However, I bet none of those people would be willing to have a nuclear power plant or waste disposal facility sited in their community. NIMBY is a powerful force in the U.S.. As always, the Golden Rule applies: do unto others as you would have them do unto you. Don’t ask others to shoulder the burden to satisfy your energy needs.

Even if the U.S. had followed through and built the Yucca Mountain facility, it would not have been large enough to accept all of the waste we would have by the time it opened. The U.S. currently has 103 operating nuclear power plants [1]. By law, the capacity of the Yucca Mountain facility was limited to 70,000 tons, of which 63,000 tons were designated for SNF and 7,000 tons for defense waste. However, it is estimated that by 2050 the U.S. will have 84,000 tons of SNF [2]. The U.S. now has SNF at over 100 sites in 42 states [3], and we have now eliminated our only option for safely disposing of it. And the federal government now pays fines of ?/year to the utility companies for breach of contract: they had promised to take the SNF off the hands of the utility companies by ?, but the waste still sits at the site of each nuclear reactor that produced it.

*Next post: The Nuclear Waste Disposal Problem

1. Wallace, M.J., Testimony before the U.S. Senate Committee on Energy and Natural Resources, Hearing on the Department of Energy's Nuclear Power 2010 Program. 2005.

2. Carter, L.J. and T.H. Pigford, Getting Yucca Mountain Right. The Bulletin of the Atomic Scientists, 1998. March/April.

3. Long, J.C.S. and R.C. Ewing, YUCCA MOUNTAIN: Earth-Science Issues at a Geologic Repository for High-Level Nuclear Waste. Annual Review of Earth and Planetary Sciences, 2004. 32(1): p. 363-401. http://arjournals.annualreviews.org/loi/earth

Saturday, May 16, 2009

Case Study: Ducktown, Tennessee

One of my favorite environmental stories centers on Ducktown, Tennessee, where native copper was discovered in 1843, and where since 1854 metal sulfides mined from the Copper Basin were smelted in ovens to separate the copper [1], [2]. Trees from the local hardwood forests fueled the ovens, which emitted sulfur oxides that combined with water in the air to form sulfuric acid. The acid stung the eyes, damaged the lungs, killed local vegetation, and leached nutrients from the soil. Without vegetation, the soil eroded away, leaving behind a thin layer of hard, red, infertile soil covering the rocks. Thus, the area surrounding Ducktown looked like the surface of Mars for many decades; U.S. astronauts said it was one of the most recognizable features on the surface of the earth. For environmentalists the good part of the story is that, by 1903, the mining companies figured out how to reduce the environmental damage caused by smelting and at the same time make more money. They simply collected the sulfur oxides released during smelting, added water to make sulfuric acid, and then sold the acid for more money than they made from selling the copper. This is an example of one of those rare “win-win” situations that businesses should always look for.

Since the 1930’s the government has been trying to revegetate the Ducktown area to reduce erosion and the amount of toxic heavy metals being dissolved and transported into local streams [2]. However, the soil is so acidic and infertile that almost nothing will grow in it except a few hardy pine species.

1. Keller, E.A., Introduction to Environmental Geology. 3rd ed. 2005: Pearson Prentic Hall. 583.

2. Kaufman, D.S., The Effect of Pine Afforestation on Copper and Iron Movement Through the Recovering Soils of the Copper basin Mining District, Ducktown, Tennessee, in Geology. 1999, Vanderbilt University: Nashville, TN. p. 135.

Thursday, May 14, 2009

Change Your Transportation

Transportation has a huge environmental impact, so society must focus on reducing that impact. Consider the environmental impact of a single automobile that travels an average of 100,000 miles in its lifetime. There is the damage that results from the manufacturing of the car and the mining and processing of the raw materials; from the drilling, transporting, and refining of the oil and gas that it uses; and from the emission of green house gases, NOx that contributes to acid rain, and ozone that causes photochemical smog. There are many other problems associated with automobiles. Driving a car is one of the riskiest activities we engage in, and cars make walking and bicycling much more dangerous on shared roads. Much of our country has been paved over by roads and parking lots, which has increased flooding risks but also uglified our landscape (I love Joni Mitchell’s song “They Paved Paradise and Put up a Parking Lot”). Driving in heavy traffic is very stressful, often leading to episodes of “road rage”. Yes, driving in the countryside without other cars can be very relaxing and enjoyable, but how often does that happen today, and is it worth all of the problems it creates? My prediction is that the most significant lifestyle change in the U.S. in the next two decades will be the abandoning of the car culture. That lifestyle won’t disappear completely, but it will become less prevalent as the price of fuel dramatically increases (due to peak oil and carbon taxes). The change may be traumatic, as 88% of workers in the U.S. travel to work by car, making the U.S. particularly vulnerable to peak oil [1]. People will choose smaller cars, cars that do not run on fossil fuels, or other modes of transportation including moped, bicycle, and mass transit. They will move closer to their jobs to decrease their transportation costs (I hope to buy a home within walking distance of my work before peak oil makes the cost unaffordable). They will take fewer long trips, and they will go to school closer to home. They will travel less for work, as companies try to cut costs. Telecommuting will become even more widespread, and in many cases, videoconferencing will make travel to meetings unnecessary. All of these changes will reduce traffic congestion and pollution, increase our national security by decreasing our dependence on foreign oil, reduce CO2 emissions contributing to global warming, and I would argue, increase our health (more walking) and quality of life (less time wasted in traffic, better scenery).

Change What You Drive

The technology of automobiles hasn’t changed dramatically over the last 100 years. Most still use a standard internal engine fueled by gasoline. Throughout my life, U.S. auto manufacturers have presented prototypes of cars that were supposed to change the way we drive, but none of them ever came to fruition. Production and leasing of the EV-1 in the 1990’s signaled a potential shift to electric cars, but GM aborted that foray into new technology by confiscating all of the cars and destroying them, as documented in the film “Who Killed the Electric Car?”. However, contrary to general wisdom and the claims of some environmentalists, electric cars currently are not better for the environment. That is because the electricity used to power them comes primarily from the burning of fossil fuels, especially coal. Also, they are inherently less efficient, because any time you convert energy from one form to another you lose some energy. Converting fossil fuels into electricity to fuel automobiles is much less efficient than using them to fuel the car with an internal combustion engine directly. The same argument holds true for the now heralded hydrogen cars, which use electricity to produce hydrogen gas H2, which in a fuel cell in the car reacts with oxygen gas O2 to produce H2O, releasing energy in the process. Although the hydrogen-fueled car emits only water, the process of producing the hydrogen requires lots of energy that usually comes from the burning of fossil fuels, which emits large amounts of CO2 and other pollutants. So how can we make cars less harmful to the environment? First we must convert our primary source of energy from fossil fuels to renewable forms like wind and solar. Then we should use the electricity that is produced to fuel plug-in gas-electric hybrid cars, or eventually to produce H2 gas for hydrogen-fueled cars.

Hybrid cars like the Toyota Prius have already raised the bar for energy efficiency. Hybrids have both a gasoline engine and electric motor. They produce electricity through regenerative braking, and automatically shut off the engine when idling. Another promising development is cars that run on biofuels such as ethanol and biodiesel. Flex cars can use ethanol or gasoline, but this is not a new technology, as it dates back to the original flex-fuel vehicle, the Model T, built in the 1910s. Many have concluded that production of ethanol from corn is not energy efficient, with some estimates showing that it requires more fossil fuel energy to produce the ethanol than is obtained from burning it. In addition, use of corn for ethanol production has increased the price of corn worldwide, which is a serious problem for the poor who depend on it for food. An increase in the price of corn causes increases in the price of all products for which corn is used as a feedstock. This problem of using food for fuel can be avoided by producing ethanol using switchgrass and wheat straw, which are also more energy efficient than corn.

So what can you do now? First, make every effort to decrease the number of miles you travel. Combine your errands. Never idle you car. Make sure your car is in tune and properly inflate the tires to maximize gas mileage. Carpool whenever possible. Make purchases online rather than driving to the store. Accelerate and decelerate slowly, and try to maintain a constant top speed. Ask your boss if you can telecommute one day per week. Vacation locally, or consider purchasing carbon offsets for the miles that you travel for vacation [2].

When the time comes to change your ride, buy a fuel-efficient hybrid as soon as you can, or even better, switch to mass transit. Encourage your employer to pay for your mass transit costs (like my employer, Vanderbilt University, they may be willing to do so because it means they will save money by building fewer parking garages). Imagine how much money you would save if you didn’t have monthly car and car insurance payments.

In the future, I envision a decentralized system of energy production for fuel-efficient homes and cars. Picture a windmill in your yard, and solar panels on your roof. The wind and the sun that power these energy sources are free and limitless. The electricity that they produce could be used to power your home and your plug-in electric car, or to produce hydrogen for the fuel cell in your car, all with zero CO2 emissions or pollution.

1. Brown, L., Plan B 3.0: Mobilizing to Save Civilization. 2008, New York, NY: W.W. Norton & Co., Inc.

2. Jeffery, Y., L. Barclay, and M. Grosvenor, Green Living for Dummies. 2008: For Dummies.

Wednesday, May 13, 2009

Book Abstract

The environmental impacts of increasing human population, consumption, and technology are now widely recognized and global in scale. Humanity is now bumping up against the limits defined by earth’s carrying capacity. Rising costs of many natural resources reflect the combined effects of shrinking supplies and increasing demand. Global production of oil has peaked and is now declining, portending long-term cost increases for fuel and food. Global production of other resources such as marine fish are also declining. Global warming threatens supplies of food and water and may make many locations uninhabitable. Overconsumption and pollution have led to water shortages in many countries. The global reserve of grain has shrank for the last eight years, and during that time the price of grains has increased 2-4x (*check). The global ecological footprint is now 1.3 Earths, meaning that the growing human population and economy have overshot the capacity of earth to regenerate resources and absorb waste by 25%. Humanity was last sustainable in the 1980's, and most global human welfare indicators have declined since the 1980's. The only solution to these multiple threats is for humanity to adopt sustainable living practices that help to preserve People, Prosperity, and the Planet and guarantee that future generations can live as well as we do today. First, we must switch energy production from fossil fuels to renewable energy sources such as wind and solar. This soft approach of decentralized use of renewable resources that do not emit CO2 is preferred over the hard approach of centralized energy production using non-renewable resources because it is sustainable and increases our energy security, and it would make the use of electric and hydrogen-fueled cars truly CO2-free. A drastic reduction in the number of coal-fired power plants can reduce the problems of CO2 emissions, acid rain, and unsafe fly ash and coal slurry ponds. Power plants that continue to burn fossil fuels could capture and sequester CO2 in the ground. Water conservation and decentralized purification or privitization can help ensure adequate, safe drinking water supplies.

In the last 100 years, cheap oil has fueled rapid global and particularly U.S. economic growth and helped us to produce the food needed by an exploding human population. As oil production drops, oil prices will rise, and so will the cost of food and nearly every product on the market. Of greatest concern is the potential increasing cost and scarcity of food. Current agricultural practice requires 10 calories of oil energy for production of one calorie of food energy. Global warming, decreasing biodiversity, and water scarcity will compound the problems of energy and food shortages. In this declining world, people will need to adapt to living with fewer resources and less wealth.

The changes that are required to make our society sustainable may be too great to achieve through action of a centralized government, particularly because the U.S. government relies on continuous economic growth and is beholden to corporate interests. On the other hand, decisions made collectively by individuals can greatly reduce the ecological footprint of societies. High prices will force people to make sustainable lifestyle choices, including purchasing fuel-efficient vehicles and decreasing miles traveled by moving to high-density housing close to the workplace. This will lead to a reversal of the decades-long migration from cities to the suburbs, eventually resulting in the rebirth of cities and decay of the suburbs. Anticipating these changes can help individuals make smart investment decisions.

The goal of this book is to convince you that change is coming. You can try to ignore or deny change, but you will be better off if you anticipate change and adapt to it. Because the change will involve resource shortages, you can best adapt by limiting your resource use. Stop living large! Reduce your consumption, and reuse and recycle everything. By reducing your ecological footprint and living sustainably, you can be happy while living on less, and because you will incur less damage on your environment, it will be able to provide you with more. On the other hand, if you continue to take more from the environment, it will have less to give you in the future. You can be happier if you simplify your life and live sustainably. Once you have reformed your own lifestyle, you can help to reduce the ecological footprint of others. Protest the opening of any new coal-fired power plants. Convince your community to switch to compact fluorescent lights or even ban incandescent lights. Try to move your workplace toward sustainability by starting recycling programs and discouraging the use or sale of disposable products such as bottled water. The more positive changes you make, the better chance our society has for survival, and the better life will be for us and our children.

Tuesday, May 12, 2009

My writing style and the use of Wikipedia

I am aiming this book at the average person who knows little about environmental science. I therefore hope to publish it in a popular press, not a specialized academic press. In addition, I would like to make it available as an inexpensive PDF file. To make the material accessible to a larger audience I am writing the book in an informal, conversational tone, using the first and second person and active voice, rather than the third person and passive voice like the scientific literature.

I have used Wikipedia quite a lot for my preliminary research. However, I recognize the need to fact-check, i.e., check the original sources to verify the claims, and cite those sources in the final version. Wikipedia makes this easy because it usually contains hyperlinks to the original sources. The need to check sources was well-illustrated by an AP story on May 12, 2009, in which an Irish college student posted a fake quote on the Wikipedia page of Maurice Jarre hours after the composer died (see http://www.msnbc.msn.com/id/30699302/). Many newspapers published the quote, demonstrating that many journalists rely on Wikipedia for information but do not verify the accuracy of that information.  The good news is that Wikipedia editors discovered the fraud within hours of it being posted and deleted it.  My plan has been to use Wikipedia as a preliminary reference; usually I use it to confirm what I already know, and so far, I've found it to be quite accurate. In fact, in 2005 the journal Nature conducted a study comparing science entries in Wikipedia and The Encyclopedia Britannica and found them to have similar levels of accuracy [1]. Wikipedia is especially useful because I can include links to its articles in my blogs, while many of the original sources are not online. During the revision stage of writing my book, I plan to fact-check and cite the original sources rather than Wikipedia. One reason I won't cite Wikipedia in my book is that the content of Wikipedia pages always changes, and future versions of a cited Wikipedia page may not support the claim I make when I cite it.

1. Giles, J., Special Report Internet encyclopaedias go head to head. Nature, 2005. 438: p. 900-901. http://www.nature.com/nature/journal/v438/n7070/full/438900a.html