HOW BIOENERGY AND FOOD CROPS THRIVE TOGETHER:A Response to the World Resources Institute's Working Paper,"Avoiding Bioenergy Competition for Food Crops and Land,"by Tim Searchinger and Ralph Heimlich
by Claude D. ConvisserFebruary 7, 2015
The World Resource Institute's January 2015 working paper ("WRI") is a commendable effort at addressing a big question: whether agricultural feedstocks used for bioenergy diminish worldwide food security. Due to the authors' overlooking the tremendous benefits of the jatropha curcas tree and Plant Oil Powered Diesel Fuel System, Inc.'s ("POP Diesel") manner of cultivating this tree on an equal footing with food crops, however, the WRI authors end up with the wrong answer of condemning all bioenergy as a means for addressing global warming.
Contrary to WRI's negative conclusion about other sources of biomass and biofuel, jatropha bioenergy versus food crops is not an either-or choice in a zero-sum game. POP Diesel's method of having indigenous farmers grow jatropha trees together with food crops on savannah land that is abundantly available in non-arid, tropical areas of the world accelerates both a lower carbon future and improved food security for humans. POP Diesel is pleased to report that its method, described below, satisfies all of the criteria set forth in WRI's Table 1 for a Sustainable Food Future, raising the income of subsistence farmers who partner with it while enhancing their communities' food security and producing affordable biofuel that can compete in the United States with petroleum fuel at any price.
As the end of this paper explains, while 100 percent jatropha plant oil, run through POP Diesel-equipped diesel engines, may not be 100 percent carbon neutral, it comes closer to that mark than any other option for powering engines. As generated by POP Diesel in conjunction with food crops, jatropha biofuel is worthy of WRI's consideration.
Below is (1) a brief explanation of POP Diesel's use of 100 percent jatropha plant oil as a substitute for petroleum diesel fuel, followed by a discussion of (2) jatropha's singular benefits as a biofuel feedstock, (3) the value of jatrohpa forestation, (4) how POP Diesel's cultivation method meets all of WRI's objectives, and (5) how the oil generated and POP Diesel's engine equipment are superior to alternative power technologies and fuels.
- A Primer on Diesel Engines and POP Diesel's Use of 100 Percent Jatropha Plant Oil in Them
- Jatropha's Singular Benefits as a Biofuel Feedstock
- The Value of Jatropha Forestation
- The Sustainability of POP Diesel's Cultivation Method Meets All WRI Objectives
- No Forests Cut Down
- No Irrigation
- Advising Best Agricultural Practices Raises Farmers' Food Crop Yields
- Helping Farmers with Logistics Boosts Their Food Crop Yields
- Increasing Income and Opportunities for Women
- Using the Jatropha Plant Oil As Is and Making Electricity and Fertilizer and Animal Feed from Its Seedcake
- Substantial Impact on Both Fuel and Calorie Supply
- An Examination of Alternative Power Technologies and Fuels Supports, by Comparison, POP Diesel's Enabling Engine Equipment and Method of Securing Jatropha Plant Oil Supply
1. A Primer on Diesel Engines and POP Diesel's Use of 100 Percent Jatropha Plant Oil in Them
Before inquiring how it is possible for POP Diesel to accomplish all of these goals, a brief foray into the fields of engine technology and fuel is necessary to lay a foundation for later discussion of agricultural development, land use, and the relative merits of renewable energy alternatives. POP Diesel is the first company to secure the approval of the U.S. Environmental Protection Agency ("EPA") for the sale of ordinary vegetable oil to fuel compression ignition (diesel) engines at 100 percent concentration, in POP Diesel's case, 100 percent jatropha plant oil in select diesel engines equipped with POP Diesel's patented auxiliary fuel system.
POP Diesel's enabling equipment works on any diesel engine. Due to the better torque diesel engines deliver, as compared to spark ignition (gasoline) or electric engines, diesels fill virtually all engine needs in the trucking, rail, power generation, mining, farming and industrial markets. Although diesel engines, in addition to delivering better torque, are more fuel efficient, require less maintenance, and last longer than gasoline engines, but Detroit has yet to embrace diesel engines in passenger vehicles. The premium Detroit charges these days for a diesel engine installed in a pick-up truck is largely a function of this engine's elite appeal. If diesels were the norm in the United States, as they are in Europe, then their price would be lower.
Run in POP Diesel-equipped diesel engines, 100 percent pure jatropha plant oil burns better than petroleum diesel. According to POP Diesel's laboratory testing, it has better cetane, a measure of the ignitability of a fuel under compression, and better natural lubricity, meaning less wear on the engine parts that come in contact with the fuel. In POP Diesel's experience, it makes the engine run more quietly and smoothly, due to its molecular structure different from petroleum diesel. Although it requires 10 percent more fuel to travel the same distance, power output from a POP Diesel-equipped engine remains the same.
The method POP Diesel describes herein of cultivating the jatropha trees together with food crops will allow POP Diesel to offer its new engine customers significant real savings in their fuel bill, no matter how low the price of petroleum goes. (POP Diesel is targeting the market for new long haul semi trucks initially, since semi trucks consume more fuel and thereby contribute more greenhouse gas emissions than any other engine platform.). Lastly, jatropha plant oil produces nitrous oxide-compliant emissions, which most other plant oils, including soy and waste vegetable oil, do not, even when they are processed into biodiesel.
2. Jatropha's Singular Benefits as a Biofuel Feedstock
WRI's self-stated focus is a sustainable food future. However, an element missing from WRI's discussion is the negative impact that global warming, if unchecked very soon, will have on world food production. Assuming that WRI's estimate of a 70 percent deficit in crop calories needed by 2050 is correct, if the level of food production drops below WRI's benchmark 2006 yield, then all chance of plugging this deficit will be lost. Urgent action on global warming is necessary to prevent the world's food shortage from getting worse.
Today, India is the only country that has established commercial scale cultivation of jatropha trees, and only with a guiding hand, and much investment, from the Indian government. Cellulosic biofuels, the object of WRI's focus, were even less proven than jatropha is today when Congress enacted targets for their production in 2007.
Time can help to ease a path for new things. Look at hydraulic fracturing, for example. Technology invented in the 1940's took decades to test and develop before conditions were ready for the fracking boom of the late 2000's. When an influential organization like WRI states its position, people listen, but when WRI condemns the entire, nascent biofuel industry, which is for all intents and purposes at most twenty years old, for the sins of other feedstock sources, it risks nipping the unique jatropha tree in the bud.
The Indian government views jatropha as such a national resource that it forbids export of the oil. Some in the private sector like POP Diesel have persevered with jatropha out of appreciation for its particular advantages as a source of bioenergy. Native to southern Mexico and spread by Portuguese traders, jatropha has adapted to all non-arid, tropical regions of the world. Because the fruit and fruit seeds whence the oil comes are toxic, if ingested, jatropha oil used as biofuel does not compete with the demand for food, in the same way that edible feedstocks that WRI criticizes do: corn and sugar cane to make ethanol and fuel gasoline engines, soy and palm oil to make biodiesel. Furthermore, jatropha has the highest yield per hectare of any oil-bearing crop, save palm, which is a foodstuff. In POP Diesel's experience, jatropha has multiple times the oil yield per hectare as soy grown in the United States, with fewer material inputs.
3. The Value of Jatropha Forestation
WRI argues that a major shortcoming of biofuel feedstocks is that they do not generate additional biomass, taking into account the default natural growth of grasses, plants and trees. POP Diesel does not dispute WRI's criticisms of cellulosic biofuels made from biomass like switchgrass to power spark ignition engines. POP Diesel concurs with WRI's acquiescence to Brazilian sugarcane, which WRI makes contingent on the destruction of no additional forest to compensate for the planting of new sugarcane on presently unforested land.
A fundamental point of agreement is that to the extent bioenergy replaces the use of a fossil fuel, it may produce a net saving in greenhouse gases added to the atmosphere. If plants are cut down to create the bioenergy, their combusted carbon stocks temporarily add to atmospheric carbon dioxide. The plants' re-growth from the earth, however, removes this same quantity of carbon dioxide from the atmosphere.
A point WRI seems to miss is that, assuming plant re-growth, the use of bioenergy merely accelerates the cycle of carbon transfer from plants to the atmosphere and back to plants. The carbon content of the initial plant harvest combusted in the first batch of bioenergy amounts to this cycle's only net addition of greenhouse gases to the atmosphere.
POP Diesel's goal, consistent with WRI's reservations, is to minimize this initial loss of carbon stocks by the selection of land it chooses or approves for jatrohpa cultivation. In contrast, every time fossil fuels combust, carbon that was safely stored underground enters the atmosphere, without any compensating sequestering taking place.
a. Jatropha Improves Ecosystems
POP Diesel differs with two premises underlying WRI's position, over (i) whether there presently exists untapped, suitable land that is not forested, and if so, (ii) whether this land can support bioenergy feedstocks, in addition to food crops. Although WRI believes that the answer to both questions is, "No," in fact, savannah land, consisting of grasses, some shrubs, and occasional trees and clusters of trees, adjoins on either side the band of equatorial rainforest circling the Earth. For example, consider the yellow and purple bands on this map of Africa:
Click here to have a rough idea of what this savannah land looks like from the air.
Some of these areas were forested before the arrival of human beings. Restoring them to their original forested state with jatropha trees does not disturb an ecosystem. It replenishes and enriches it. For example, farmers in Mexico inform POP Diesel that when they plant jatropha trees on scrubland, biodiversity improves. Bees and ants, feeding from the flowers of the jatropha fruit, abound and spur pollination. A higher density of trees leads to a richer and more diverse surrounding plant life. Insects swarm, attracting birds and small animals, which draw bigger predators.
Since human activity, including global warming, is contributing to the southern advance of the Sahara desert, it is not valid to argue that humans should not upset the "balance" of its border savannah ecosystem. This balance is already under siege due to climate change.
Jatropha trees planted across unforested land in tropical regions can help bolster rainfall by their evapo-transpiration, block the advance of deserts, add cover, and return rich animal life to denuded environments. Jatropha is ideally suited to these tasks because it grows in all land and moisture conditions, provided that temperature does not dip below 60? F (15.5? F). It also makes an amazingly rapid recovery from the brush fires common in the Tropics. Click here to see video of fresh jatropha bushes sprouting from the roots of their burnt antecedents. Thus, jatropha cultivation, paired with food crops, restores, rather than stresses, ecosystems.
b. Jatropha Is Highly Efficient as a Carbon Sequestration Device
WRI does not acknowledge that some plants are simply better and more efficient at removing carbon from the atmosphere than others, in particular, the jatropha tree. Once in place, it is nature's best carbon sequestration device, or second best, next to palm, more efficient than any machine man could invent, especially for turning carbon dioxide extracted from the atmosphere into a beautiful hydrocarbon oil that burns better than petroleum in diesel engines. As WRI points out, palm, used to make biofuel, crimps the supply of palm used as a foodstuff, a choice inedible jatropha does not present. The jatropha tree's ability to turn greenhouse gases into plant hydrocarbon oil, the functional equivalent of petroleum diesel, puts jatropha head and shoulders above ordinary biomass, the target of WRI's critique, in terms of global warming mitigation.
The efficiency of the jatropha tree as a carbon sequestration tool transforms WRI's visual representations of bioenergy versus food calories into the following:
A carbon balance demonstration and explanation published here shows that planting one jatropha tree and one castor plant, also an oil-bearing plant, in a three-meter-a-side square with eight-foot tall switch-grass cut down and removed will require no longer than three years for the lost carbon stock to be returned to that plot of land. Three-and-a-half years after planting, the jatropha tree produces enough fruit seeds to make 350 gallons of plant hydrocarbon oil per hectare, which, together with the carbon contained in the woody mass of the emergent jatropha tree and castor plant, is enough to recoup the removal of pre-existing carbon stock. This oil yield is a conservative figure. Jatropha trees under the care of POP Diesel personnel have given annual yields of 818 gallons (3,096 liters) per hectare at seven years of age, using sustainable farming methods and non-hybrid, local jatropha seeds.
On the other hand, consider WRI's suggested formula that feedstock plants cut down to make cellulosic biofuels and ethanol deplete carbon stocks and when these plants grow anew, they do not add any new overall biomass to tip the scale of the carbon balance. If switch-grass already eight feet tall were allowed to grow for four more years, it might add a few feet to its height, but this added carbon stock would not compare to the carbon mass contained in the growth of the replacement jatropha tree and castor plant, plus the minimum of 400 gallons (1,514 liters) of plant hydrocarbon oil per year that mature jatropha trees will produce per hectare over their 30 to 50 year life span. The foregoing equation does not even count plant hydrocarbon oil coming from the castor planted along with the jatropha.
In sum, different varieties of plants absorb and store carbon from the atmosphere at different rates. As WRI acknowledges, if the addition of biomass, plus hydrocarbon oil by oil-generating trees and plants, on land already lacking in vegetation takes more carbon out of the atmosphere than the land would extract in naturally re-vegetating, there are "greenhouse gas benefits." WRI Report, page 30. Smart choices about where to plant jatropha trees and what amount of vegetation, if any, it is acceptable to remove in favor of planting these trees can allow the fuel use of jatropha plant oil, used as fuel, to make a meaningful difference in mitigating global warming.
4. The Sustainability of POP Diesel's Cultivation Method Meets All WRI Objectives
POP Diesel's criteria for growing jatropha in consort with food crops skirt all of the pitfalls highlighted by WRO and capitalize on all of its suggested agricultural practices.
a. No Forests Cut Down
POP Diesel supports farmers to grow jatropha, paired with food crops, on their own land, land that is already savannah land, land that was cleared years ago, if not in antiquity, or historically unforested in nature. POP Diesel does not cut down forest or wooded savannah land to grow jatropha trees, since eliminating these carbon stocks would be counterproductive to combating global warming. Where POP Diesel encounters a tree or tree cluster taller than 15 feet, it leaves the trees in place. If for some unusual reason, it must cut them down, it replaces them by planting two new, non-jatropha tree saplings for every bigger tree leveled.
b. No Irrigation
POP Diesel does not, in general, irrigate. It relies, instead, on natural rainfall, except in specific instances, such as to irrigate a seedling nursery.
c. Advising Best Agricultural Practices Raises Farmers' Food Crop Yields
POP Diesel provides all material support, in terms of seeds, organic herbicides, and produce bags, that participating farmers need to grow both jatropha trees and a food crop of their choice on equal parcels of land, year after year. (After two years, jatropha trees grow big enough to form a canopy that blocks sunlight from nourishing any crops planted beneath them; hence, the food crop cultivation occurs on separate tracts of land.). POP Diesel remains in continuous contact with its farmer partners, giving them detailed technical guidance on best agricultural practices.
WRI favors improving agricultural yields as a means of closing the calorie gap. POP Diesel reports that many of the subsistence farmers it works with have used inefficient practices in the past, such as planting crops so sparsely that they fail to achieve an economical yield. Simply advising or inducing them to plant more intensively can double their harvest and resulting farm income.
Of course, if such advances come at the expense of depleting the soil, they are not sustainable. POP Diesel embraces WRI's recommendation for cover crops, crops such as peanuts, soy and other beans, planted after the main harvest, that return nitrogen to the soil. The harvest of a cover crop not only gives the farmer an additional source of income, it obviates the need for the following year's dose of petroleum-derived fertilizer. POP Diesel gives farmers cover crop seeds and encourages them to plant them. If they fail to harvest the resulting cover crop, they can plow it over to further enrich the soil.
d. Helping Farmers with Logistics Boosts Their Food Crop Yields
From POP Diesel's field research, it appears that WRI's calorie gap is partially a function of not only inferior agricultural practices, but also logistical problems in developing countries. Where back roads are little more than unpaved tracks that become muddy and treacherous during the rainy season, subsistence farmers often lack the means of transporting their harvest from their fields in the interior to the main, paved road, and of bringing material back to their fields. Rather, they must rely on their heads to carry things, or if they are lucky, a donkey. Simply equipping POP Diesel's farm production assistants with motor vehicles to pick up and take away farmers' harvest and bring them material has the potential to increase the delivery of produce to the market, and farmers' income, exponentially.
e. Increasing Income and Opportunities for Women
Fair trade means more benefits for women, of particular interest to WRI. Jatropha trees grown in the right climate and soil conditions fruit two or three times a year. After the saplings grow to form a tree canopy covering the aisles in the third year after planting, the main labor every year is the fruit harvest. One or two harvests occur during the dry season, when farmers are not busy. Jatropha fruit harvesting is casual work well suited to women and even children who can fit this task in between school and other chores, in the same way that full families contribute to the farm harvest in the United States and all over the world. Rising farm incomes improve educational opportunities for girls. Jobs created by agricultural development projects give women new avenues for employment and advancement. POP Diesel places a premium on ensuring that women hold a sizable number of the jobs it creates.
f. Using the Jatropha Plant Oil As Is and Making Electricity and Fertilizer and Animal Feed from Its Seedcake
POP Diesel leaves the jatropha plant oil in its natural state and has EPA authorization to sell it as fuel in that natural state to customers of POP Diesel's EPA-approved engines. POP Diesel does not process the plant oil into biodiesel, which avoidance halves the energy invested in the final fuel, halves resulting carbon emissions, and spares the use of dangerous processing chemicals and hazardous waste left over.
Using the jatropha plant oil as fuel in its natural state enables POP Diesel to burn the seedcake byproduct as biomass to make electricity. Since POP Diesel needs less than half of this electricity to power its industrial facility, the remainder can bring electricity to local communities or enter the national grid.
Jatropha seedcake also makes excellent fertilizer, due to its high (46%) nitrogen content and organic matter and its physical structure, which increases soil fauna (worms and other soil microbes) and water percolation. Applying this seedcake fertilizer to farmland POP Diesel works with raises food production and puts land that was previously unproductive to beneficial use.
In addition, jatropha seedcake can be turned into protein-rich animal feed, rendering moot a narrow choice between jatropha cultivation and livestock rearing.
Coming from jatropha trees planted on savannah land, jatropha seedcake, replenished after each harvest and fruit pressing, constitutes additional biomass that would not otherwise exist. Therefore, it should meet with WRI's approval.
g. Substantial Impact on Both Fuel and Calorie Supply
For every 4.6 million gallons of jatropha plant oil (17 million liters) that POP Diesel produces per year, POP Diesel will assist farmers to grow, harvest, and receive the additional income from 60,000 metric tons of harvested food crops (assuming a mix of one third each of maize, rice and soy) and 30,000 metric tons of cover crops (soy). (These numbers are based on the past experience of POP Diesel personnel.). These figures translate into 118 billion additional food calories in total per year, or enough to feed 162,000 people a diet of 2,000 calories per day for the year. This method will also permit POP Diesel to sell jatropha plant oil as fuel in POP Diesel-equipped diesel engines at any price competitive with petroleum diesel.
In only three tropical countries, consisting of Mexico and one small country in Africa and one in South Asia, universities and governments have estimated that there are a total of 16.3 million hectares suitable for jatropha cultivation, enough to make 5.4 billion gallons of oil and displace 9 percent of the petroleum diesel used in the United States. Coupling this jatropha cultivation with equal planting of food crops on available, non-forested agricultural land will mark a significant step towards closing the calorie gap, while also averting additional global warming by weaning our economy of fossil fuel petroleum.
5. An Examination of Alternative Power Technologies and Fuels Supports, by Comparison, POP Diesel's Enabling Engine Equipment and Method of Securing Jatropha Plant Oil Supply
Just as WRI objects to the carbon accounting that has justified cellulosic ethanol feedstocks, POP Diesel has objected to EPA's accounting of carbon emissions towards meeting its obligation, ordered by the U.S. Supreme Court in Massachusetts v. EPA, to "take steps to slow or reduce" global warming caused by motor vehicle fuel combustion. 549 U.S. 497, 525 (2009) (emphasis supplied). EPA has measured carbon emissions from engines and fuels solely by what comes out the tailpipe.
However, this Tailpipe Rule produces warped results. The Tailpipe Rule ignores two elements that would be counted in a proper life cycle analysis: (1) the comparative greenhouse gas emissions caused upstream to extract the petroleum from the earth or to plant the trees and harvest the oil-bearing fruit and seeds and process these raw materials into fuel, as well as (2) any benefit that the particular type of fuel has in sequestering carbon from the atmosphere. As explained above, in the case of jatropha plant oil powering a POP Diesel-equipped diesel engine, carbon sequestration is substantial.
By taking into account the true life cycle impact of a fuel and its engine technology, a nuanced comparison of different alternatives becomes possible. The conclusion that emerges is that ordinary jatropha plant oil, run through a POP Diesel-equipped engine at 100 percent concentration, produces singular benefits for mitigating atmospheric greenhouse gas accumulation and global warming. In addition, as set forth below, the non-bioenergy solutions touted by WRI appear less effective by comparison.
a. Biodiesel and "Renewable Diesel"
Biodiesel starts as plant oil or animal fat, but processing actually restructures the vegetable oil molecule into the new molecule called "biodiesel." Biodiesel can be mixed with petroleum in the single tank of a diesel engine, but nationwide fuel quality standards limit this blend to at most, a 5 to 20 percent share of biodiesel, meaning the remaining 80 to 95 percent is still petroleum diesel. With POP Diesel's inexpensive auxiliary fuel system installed, the same engine can run on 100 percent jatropha plant oil, except for brief start-up and shut-down periods on petroleum diesel. (The payback period in which a new, long haul semi truck engine recoups its investment in POP Diesel's enabling equipment will be six months, with savings continuing after that.). As stated above, turning plant oil into biodiesel doubles the amount of energy invested in the feedstock, likely contributing twice as many greenhouse gas emissions to the atmosphere as if a POP Diesel-equipped engine combusted the plant oil in its natural state.
"Renewable diesel" fuel, also known as "hydro-processed esters and fatty acids," or HEFA's, consists of plant oil that is hydrotreated and then refined as though it were crude petroleum oil. The hyrdrotreating stage requires large amounts of hydrogen, which comes from fossil fuel combustion. As with biodiesel, the complete manufacturing process requires the expenditure of at least double the entirety of the energy required to plant, grow and harvest the plant oil that POP Diesel uses and sells as fuel in its ordinary state, and likely emits double the net life cycle greenhouse gas emissions. Therefore, "renewable diesel" is not nearly as sustainable as POP Diesel Fuel consisting of 100% jatropha plant oil.
b. Photovoltaic Solar Arrays, Electricity to Power Engines, and Electric versus Diesel Engines
Although photovoltaic ("PV") solar energy is a crucial element in a sustainable energy future, first, PV's solar conversion efficiency does not approach jatropha plant oil's when it comes to powering an engine or fuel oil burner. Second, electric motors of a comparable size are not capable of producing the torque sufficient to power heavy duty engines and machinery.
There are multiple layers of inefficiency when it comes to creating PV electricity and powering an engine with it that WRI does not consider in its embrace of PV. Just as planting jatropha must justify the payback period for removing existing carbon stocks, solar panels and solar infrastructure require the expenditure of energy and corresponding emissions for their manufacture, including the mining of the metals from the earth that go into their construction. A PV panel will take between one and three years of operation to return the amount of energy that went into its creation, in the time range that a jatropha tree planted on non-forested savannah land will take to restore lost carbon stock. This figure does not count the payback period to recover the energy invested in the other components of a solar array.
As stated by WRI, battery technology presently suffers from inefficiencies that undermine claims of vast savings coming from PV to power motor vehicles. WRI's argument that "electric motors can be 2-3 times more efficient than internal combustion engines" appears to be a comparison of efficiency when an electric engine is running at or near its rated load, versus when the internal combustion engine is running at below 50 percent loaded capacity. When diesel engines run at 50 percent or higher of their rated load, as most electric engines are designed to do, then they have the same level of efficiency.
Looking at the source of electricity generated in the United States, coal accounts for 39 percent; natural gas, 27 percent; wind, 4.13 percent; and solar, 0.23 percent. The thermal efficiency of combustion to produce electricity, 33 percent efficient for coal or natural gas combustion, is actually less than the thermal efficiency of compression ignition powering a diesel engine, at 36 to 41 percent. Not only is it less energy efficient, but the combustion of coal produces between 25 and 50 percent more carbon dioxide than petroleum. Natural gas produces lower carbon dioxide emissions than petroleum, but it is still a fossil fuel whose combustion, by definition, adds greenhouse gases to the atmosphere without any corresponding sequestration taking place, as with jatropha biofuel.
In sum, while renewable electricity holds promise for the future, it should not lead to the shunning of viable alternatives for powering motor vehicle engines, such as jatropha plant oil, especially since electric motors do not produce the torque necessary to replace diesel engines in the heavy duty sector.
c. Hydrogen Fuel Cell
As is the problem with electric-powered engines, "[the main sources of hydrogen currently are hydrocarbon feedstocks, such as natural gas, coal, and petroleum, all of which also produce CO2."
d. Natural Gas, Di Methyl Ester, and Propane Fuel for Engines
Thankfully, WRI does not embrace natural gas as a viable solution to power engines. A study co-authored by scientists from the Environmental Defense Found found that, due to methane leakage in the supply chain, it would take 80 years for compressed natural gas to save any net greenhouse gas emissions if run in passenger vehicles and 300 years, if run in trucks. Even if natural gas were truly environmentally sustainable, it runs hot and dry in engines, tending to wear them out prematurely. The two big engine manufacturers who had started development of a natural gas-powered engine for long-haul trucking, Cummins and Volvo, shelved these plans in 2014.
Another gaseous fuel called "di methyl ester," which must be put under pressure to reach its liquid state for engine use, is most likely to derive from coal. It suffers from similar drawbacks to natural gas in terms of practicality and sustainability. Although Congress has classified propane, a form of liquefied petroleum gas, as an alternative fuel, it is not in any sense renewable.
e. Jatropha Plant Oil Running at 100 Percent Concentration Is the Best
In short, to power trucks and other heavy duty platforms, diesel engines and some kind of diesel fuel are needed. One hundred percent jatropha plant oil gives by far the biggest greenhouse gas mitigating value, from a life cycle perspective, and superior performance to all the rest. Perhaps if WRI considered the true cost of the alternatives described above to jatropha bioenergy, it might re-calibrate its findings accordingly. WRI is willing to support a theoretical engine technology like the hydrogen fuel cell and to favor electric vehicles, whose battery technology it admits is still wanting, powered by as-yet un-deployed solar arrays. Is WRI willing to give jatropha, cultivated responsibly together with food crops, breathing space to prove its worth?
 The author is the President and General Counsel of POP Diesel and the Director of its agricultural subsidiaries located on three continents.
 These criteria are (1) poverty alleviation, (2) benefits for women, (3) ecosystem preservation, (4) agricultural greenhouse gas emissions control, and (5) water resource conservation.
 Switchgrass and elephant grass grow to a height of 10 to 12 feet tall. Sources: Clark T. Garland, Growing and Harvesting Switchgrass for Ethanol Production in Tennessee (UT Biofuels Initiative ) (available at: https://utextension.tennessee.edu/publications/Documents/SP701-A.pdf); http://www.blueplanetbiomes.org/elephant_grass.htm; G. Moore, P. Sanford, & T. Wiley, Perennial pastures for Western Australia, Bulletin 4690 (Department of Agriculture and Food, Western Australia, Perth 2006).
 Sources: Greenhouse Gas Assessments of Jatropha Oil Production: Literature Review and Synthesis, Draft Report prepared for EPA, Sept. 2012, page 3-1 ("When looking at the total energy consumption of using jatropha for biodiesel, transesterification [of the oil into biodiesel] accounted for 61% of all energy consumption, while cultivation only accounted for 12% in a study of jatropha in West Africa;" another study reports that transesterification accounts for 40% of all energy consumed in making jatropha biodiesel); U.S. National Renewable Energy Laboratory, Effects of Biodiesel on Pollutant Emissions, 2005 slide-show, slide 3 (soy oil conversion to biodiesel consumes nearly as much energy as soybean agriculture, crushing and transport, combined).
 Sources: Greenhouse Gas Assessments of Jatropha Oil Production: Literature Review and Synthesis, Draft Report prepared for EPA, Sept. 2012, page 3-1 ("When looking at the total energy consumption of using jatropha for biodiesel, transesterification [of the oil into biodiesel] accounted for 61% of all energy consumption, while cultivation only accounted for 12% in a study of jatropha in West Africa;" another study reports that transesterification accounts for 40% of all energy consumed in making jatropha biodiesel); U.S. National Renewable Energy Laboratory, Effects of Biodiesel on Pollutant Emissions, 2005 slide-show, slide 3 (soy oil conversion to biodiesel consumes nearly as much energy as soybean agriculture, crushing and transport, combined). WRI's call to expand grazing land for livestock is contrary to the goal of averting global warming. Animal meat is an inefficient delivery mechanism for calories that could otherwise come from plant matter. Livestock graze on land that could otherwise serve as a carbon sink. Their methane emissions make a potent contribution to greenhouse gas accumulation. As Tim Searchinger, the lawyer who is the principal author of the WRI report, told The Washington Post: "It's pretty much a consensus view among global environmental scientists that we would be better off if we ate less meat." Think of Earth, Not Just Your Stomach, Advises Nutrition Panel (Feb. 20, 2015) (reporting recommendations of federal advisory panel to Dietary Guidelines that Americans consider the impact on the environment when choosing what to eat).
While children may deserve high protein meat to grow, shifting to a diet of more vegetables and less meat is a rational decision that adults can make to significantly reduce their carbon footprint. Current world cereal production has the potential to sustain 10 billion humans on a basic vegetarian diet. Source: Joel E. Cohen, Meat (First Annual Malthus Lecture, March 3, 2010, Washington, D.C.) (available at: www.prb.org/pdf11/cohen-lecture.pdf).
 Source: http://sunlightsolar.com/category/blog/page/4 (posted on May 9, 2011; last checked on Feb. 5, 2015).
 Source: U.S. Energy Information Administration ("EIA"), http://www.eia.gov/tools/faqs/faq.cfm?id=427&t=3 (last checked on Feb. 5, 2015).
 Sources: http://en.wikipedia.org/wiki/Fossil-fuel_power_station (last checked on Feb. 5, 2015); SAE International, Diesel Engine Technology Academy, Vol. 1, at 28 (Dec. 13, 2010).
 Source: http://www.eia.gov/energy_in_brief/article/role_coal_us.cfm (posted on Jan. 30, 2012).
 Source: ElA, Office of Integrated Analysis and Forecasting, Office of Coal, Nuclear, Electric and Alternate Fuels, "The Impact of Increased Use of Hydrogen on Petroleum Consumption and Carbon Dioxide Emissions," at xi (Sept. 2008).
 Source: R. Alvarez, S. Pacala, J. Winebrake, W. Chameides, and S. Hamburg, Greater Focus Needed on Methane Leakage from Natural Gas Infrastructure, 109 Proceedings of the National Academy of Sciences 6435 (April 24, 2012).