Savory advocates using bunched and moving livestock in an effort to mimic nature, as a means to heal the environment, stating "only livestock can reverse desertification. There is no other known tool available to humans with which to address desertification that is contributing not only to climate change but also to much of the poverty, emigration, violence, etc. in the seriously affected regions of the world."[2] "Only livestock can save us."[3] He believes grasslands hold the potential to sequester enough atmospheric carbon dioxide to reverse climate change. Praised by cattle farmers,[4][5] his controversial ideas have sparked opposition from academics; ranging from debate on evidence for treatment effects to the scope of the potential impact for carbon sequestration.[6][7][8]
Savory received the 2003 Banksia International Award[9] and won the 2010 Buckminster Fuller Challenge.[10]Prince Charles called him "a remarkable man" and noted farmer Joel Salatin wrote, "History will vindicate Allan Savory as one of the greatest ecologists of all time."[11]
In contrast, James E. McWilliams described Savory as having "adherence to scientifically questionable conclusions in the face of evidence to the contrary".[8]George Monbiot said of him, "his statements are not supported by empirical evidence and experimental work, and that in crucial respects his techniques do more harm than good."[12] However, this comment has been subject to criticism in a later article published in The Guardian by Hunter Lovins, titled "Why George Monbiot is wrong: grazing livestock can save the world".[13]
Life
Education
Savory was educated in South Africa at what was then the University of Natal, gaining a B.Sc. in Biology and Botany in 1955.[14][15]
Early work in southern Africa
Captain Savory
Savory’s early career was multifaceted, working as a biologist, soldier, public servant, member of parliament, president of a political party, farmer, rancher, and as a consultant.[16] The insights from these experiences eventually culminated in what is now known as Holistic Management.
His work studying the root cause of land degradation (desertification) began as early as 1955 in Northern Rhodesia (now Zambia), where he served in the Colonial Service as Provincial Game Officer for Northern and Luapula Provinces.[17] His work continued in Southern Rhodesia (now Zimbabwe), first as a research officer in the Game Department and then as an independent scientist and international consultant.[18]
Savory’s early research advocated for the culling of large numbers of elephants based on the belief that large numbers of grazing herbivores were destroying their own habitat,[19][20] a mainstream belief that persists with many anti-livestock proponents to this day. His recommendations were not enacted during his time in the Game Department, but later in 1969 as a Member of Parliament he brought about a Parliamentary Commission of Enquiry led by George Petrides charged “to investigate and report on all aspects of wild life policy and management in Rhodesia and to make recommendations thereon." Following the recommendations of the Petrides Commission, Dr. Graham Child was appointed Director of National Parks and Wild Life Management who then implemented an elephant culling program. In a 2004 article discussing the program, Dr. Child noted that “while I was Director 30,529 [elephants] were killed, mostly on culls, and the countrywide population grew from an estimated 44,109 to 52,583 animals.”[21]
However, this culling program did not reverse the degradation of the land as expected, and Savory has called his decision to advocate for the culling of large numbers of elephants "the saddest and greatest blunder of my life."[22][23] This preventable loss of life, the result of interpreting research data to fit the prevailing world-view that too many animals causes overgrazing and overbrowsing, led to Savory becoming even more determined to understand and resolve the root cause of land degradation and to prevent others from making the same short-sighted mistakes which he attributed to applying reductionist thinking to complex living systems. This eventually led to Savory's development of a holistic framework for decision-making and to the creation of Holistic Planned Grazing, as detailed in his books, Holistic Management, Third Edition: A Commonsense Revolution to Restore Our Environment, written with his wife Jody Butterfield, and Holistic Management Handbook, Third Edition: Regenerating Your Land and Growing Your Profits, written with Sam Bingham and Jody Butterfield.
Savory was influenced by earlier work of French agronomist André Voisin who said that overgrazing resulted from the amount of time plants were exposed to animals, not from too many animals in any given area.[24] Savory saw this as a solution to overgrazing, and believed that overgrazing was caused by leaving cattle too long and returning them too soon, rather than the size of the herd.[25][26]
Military involvement
Savory says in his memoir that he enlisted as a ranger with the British Colonial Service in the Northern Rhodesian Game Department to prepare himself for guerilla warfare - learning techniques like bush skills and tracking of animals like elephants from local traditions, which could then have military applications in counter-insurgency.[27] In the early 1960s, when Savory was a Territorial (reserve) Army officer, he wrote to Federal Prime Minister Roy Welensky recommending the military prepare for impending guerrilla warfare by training trackers - a recommendation which was rejected by conservative senior officers.[28] However, in the early 1960s, his ideas began to gain acceptance when the Federal Army's elite all-white Special Air Service (SAS) invited him to present courses on tracking and "aggressive bush craft" - which were deployed against African nationalist insurgent groups fighting against the colonial government.[28]
At the time of Unilateral Declaration of Independence in 1965, Savory was a Captain in the part-time Territorial Army unit, the 4th Battalion Royal Rhodesia Regiment. He opposed UDI quietly. In 1965, Savory presented a paper to Rhodesian Army Headquarters suggesting the formation of a Guerrilla Anti-terrorist Unit (GATU) with white SAS operators and black police who would specialize in tracking, and pose as African nationalist insurgents to infiltrate and eliminate their groups - this request was approved, but disagreement between army and police led to the unit's termination.[28] Before GATU was disbanded, Savory recalls that on operations "we whites were blackened with special dye produced for us".[27] Subsequently, the army allowed Savory to select members of the entirely white Territorial Army, who were also rangers from the Rhodesian Department of National Parks and Wildlife Management (DNPWLM), and civilian professional hunters to form the Tracker Combat Unit (TCU) - as the unit had no black personnel, plans to infiltrate groups were abandoned, and re-focused on tracking and killing African nationalist insurgents.[28] After Savory’s departure from the TCU, it later evolved to become the Selous Scouts.[29][30]
Political involvement
Savory was elected to the Rhodesian Parliament representing Matobo constituency in the 1970 election. After resigning from the Rhodesian Front in protest over its policies and handling of the war, in 1973 Savory reformed the defunct Rhodesia Party formerly led by Sir Roy Welensky. Savory stated in March 1973 that the primary aim of the Rhodesia Party under his presidency was "to ensure the long-term future of the European in Rhodesia through strong and just government" and as part of this white economic superiority must be maintained, but the extreme differences between white and black wages should be lessened so that "good government" would reduce calls for "self-government".[31] The party also stated that it did not want African members, and in March 1973 stated that it "will not be a party to a coalition with African members of Parliament".[31] In May 1973, Savory stated that the Rhodesia Party supported racial segregation including of schools and hospitals, recommending that only Africans who have to work in towns such as domestic servants should be housed in urban areas - and suggested the introduction of a "Minister for Population Control" who would handle the "population explosion" among Africans.[31] In June 1973, Savory publicly stated, "If I had been born a black Rhodesian, instead of a white Rhodesian, I would be your greatest terrorist."[32] Although he urged white Rhodesians to understand why he would feel this, the reaction to this statement led to Savory's ousting from the Rhodesia Party. In 1977, other moderate white parties united in opposition to Ian Smith in what was known as the National Unifying Force (NUF) led by Savory.[33] The NUF party won no seats in the 1977 election, and Savory relinquished leadership to Tim Gibbs, son of Rhodesia's last governor. Savory continued to fight Ian Smith and his policies, in particular opposing the Internal Settlement under Bishop Abel Muzorewa.[34] In 1979, due to conflicts with the Smith government, Savory left Rhodesia and went into self-imposed exile to continue his scientific work.[32]
Move to the Americas
After leaving Zimbabwe, Savory worked from the Cayman Islands into the Americas, introducing holistic planned grazing as a process of management to reverse desertification of 'brittle' grasslands by carefully planning movements of dense herds of livestock to mimic those found in nature, allowing sufficient time for the plants to fully recover before re-grazing. Savory immigrated to the US, and with his wife Jody Butterfield founded the Center for Holistic Management in 1984. Its name was later changed to the Savory Center and later Holistic Management International. In 2009 Savory left HMI and formed the Savory Institute. Savory, Butterfield and philanthropist Sam Brown formed the Africa Centre for Holistic Management, based in Zimbabwe in 1992 on 2,520 hectares (6,200 acres) of land Savory donated for the benefit of the people of Africa as a learning/training site for holistic management.[35]
Allan Savory and Jody Butterfield 2003
Personal life
When not travelling the world spreading his message, Savory and Butterfield split their time between their house in Albuquerque and a thatched-roof complex of mud huts in the African bush in Zimbabwe. He frequently goes barefoot.[36]
Holistic management advocacy
His 2013 TED Talk, "How to green the desert and reverse climate change,"[22] attracted millions of views and was followed up by the release of his TED Book, The Grazing Revolution: A Radical Plan to Save the Earth.[37] In his TED Talk Savory asks, "What are we going to do?"
"There is only one option, I'll repeat to you, only one option left to climatologists and scientists, and that is to do the unthinkable, and to use livestock, bunched and moving, as a proxy for former herds and predators, and mimic nature. There is no other alternative left to mankind."[38]
"The number one public enemy is the cow. But the number one tool that can save mankind is the cow. We need every cow we can get back out on the range. It is almost criminal to have them in feedlots which are inhumane, antisocial, and environmentally and economically unsound."[41]
Savory condemns the practice of slash-and-burn cultivation of forests and grasslands,[40] saying that it "leaves the soil bare, releasing carbon, and worse than that, burning one hectare of grassland gives off more, and more damaging, pollutants than 6,000 cars. And we are burning in Africa, every single year, more than one billion hectares of grasslands, and almost nobody is talking about it."[38] One billion hectares is an area greater than that of the Sahara desert.
Praise and criticism
Farmers, ranchers, pastoralists and various organizations are working globally to restore grasslands through the teaching and practice of holistic management and holistic decision making.[42] This includes conservation projects in the US, Africa, Mexico, Argentina, Chile, Canada, and Australia in which various NGOs, government agencies and universities are practicing holistic management and its holistic planned grazing to reverse desertification using livestock as the main agent of change to restore the environment, increase ground cover, soil organic matter and water retention, replenish streams, and combat biodiversity loss.[39][43]
In 2003 Australia honored Savory with the Banksia International Award "for the person doing the most for the environment on a global scale"[9] and in 2010, Savory and the Africa Centre for Holistic Management won The Buckminster Fuller Challenge,[10] an annual international design competition awarding $100,000 "to support the development and implementation of a strategy that has significant potential to solve humanity's most pressing problems".[44]
Savory has faced criticism for his political and military involvement in colonial Rhodesia in the 1970s - particularly for supporting racial segregation and proposing a "Minister for Population Control" to handle the "population explosion" among Africans during his presidency of the Rhodesia Party,[31][45] and for developing and teaching tracker techniques for all-white military units which were used to track and kill African nationalist insurgents fighting against the colonial government.[28][46]
Savory has faced criticisms for claiming the carbon sequestration potential of holistic grazing is immune from empirical scientific study.[47] For instance, in 2000, Savory said that "the scientific method never discovers anything" and “the scientific method protects us from cranks like me".[48] A 2017 factsheet authored by Savory stated that “Every study of holistic planned grazing that has been done has provided results that are rejected by range scientists because there was no replication!".[49] TABLE Debates sums this up by saying "Savory argues that standardisation, replication, and therefore experimental testing of HPG [Holistic Planned Grazing] as a whole (rather than just the grazing system associated with it) is not possible, and that therefore, it is incapable of study by experimental science", but "he does not explain how HPG can make causal knowledge claims with regards to combating desertification and climate mitigation, without recourse to science demonstrating such connections."[47]
Savory's approach to the problem of desertification has met resistance from scientists. A meta-analysis of relevant studies between 1972 and 2016 found that Holistic Planned Grazing had no better effect than continuous grazing on plant cover and biomass, although it may have benefited some areas with higher precipitation.[50] Conversely, three 2007 and 2010 studies document soil improvement as measured by soil carbon, soil biota, water retention, nutrient-holding capacity, and ground litter on grazed land using multi-pasture grazing methods compared to continuously grazed land.[51][52] There is also evidence that multi-pasture grazing methods may increase water retention compared to non-grazed land.[53] However, George Wuerthner, writing in The Wildlife News in a 2013 article titled, "Allan Savory: Myth And Reality" stated, "The few scientific experiments that Savory supporters cite as vindication of his methods (out of hundreds that refute his assertions), often fail to actually test his theories. Several of the studies cited on HM web site had utilization levels (degree of vegetation removed) well below the level that Savory actually recommends."[54]
There is a less developed evidence base comparing Savory's methods with the absence of livestock on grasslands. Several peer-reviewed studies have found that excluding livestock completely from semi-arid grasslands can lead to significant recovery of vegetation and soil carbon sequestration.[55][56][57][58][59] A 2021 peer-reviewed paper found that sparsely grazed and natural grasslands account for 80% of the total cumulative carbon sink of the world’s grasslands, whereas managed grasslands have been a net greenhouse gas source over the past decade.[60] A 2011 study found that multi-paddock grazing of the type endorsed by Savory resulted in more soil carbon sequestration than heavy continuous grazing, but very slightly less soil carbon sequestration than "graze exclosure" (excluding grazing livestock from land).[61] Another peer-reviewed paper found that if current pastureland was restored to its former state as wild grasslands, shrublands, and sparse savannas without livestock this could store an estimated 15.2 - 59.9 Gt additional carbon.[62]
In his TED talk, Savory claimed that holistic grazing could reduce carbon dioxide levels to pre-industrial levels in a span of 40 years. According to Skeptical Science, "it is not possible to increase productivity, increase numbers of cattle and store carbon using any grazing strategy, never-mind Holistic Management [...] Long term studies on the effect of grazing on soil carbon storage have been done before, and the results are not promising.[...] Because of the complex nature of carbon storage in soils, increasing global temperature, risk of desertification and methane emissions from livestock, it is unlikely that Holistic Management, or any management technique, can reverse climate change.[63]". Commenting on his TED talk "‘How to fight desertification and reverse climate change’, Savory has since denied claiming that holistic grazing can reverse climate change, saying that “I have only used the words address climate change… although I have written and talked about reversing man-made desertification”.[47]
According to a 2016 study published by the University of Uppsala, the actual rate at which improved grazing management could contribute to carbon sequestration is seven times lower than the claims made by Savory. The study concludes that holistic management cannot reverse climate change.[64] A study by the Food and Climate Research Network in 2017 concluded that Savory's claims about carbon sequestration were "unrealistic" and very different from those issued by peer-reviewed studies.[65] The FCRN study estimates that, on the basis of meta-study of the scientific literature, the total global soil carbon sequestration potential from grazing management ranges from 0.3-0.8 Gt CO2eq per year, which is equivalent to 4-11% of total global livestock emissions, and that “Expansion or intensification in the grazing sector as an approach to sequestering more carbon would lead to substantial increases in methane, nitrous oxide and land use change-induced CO2 emissions”[65] Project Drawdown estimates the total carbon sequestration potential of improved managed grazing at 13.72 - 20.92 Gigatons CO2eq between 2020–2050, equal to 0.46-0.70 Gt CO2eq per year.[66] A 2022 peer-reviewed paper estimated the carbon sequestration potential of improved grazing management at a similar level of 0.15-0.70 Gt CO2eq per year.[67]
"I have been particularly fascinated, for example, by the work of a remarkable man called Allan Savory, in Zimbabwe and other semiarid areas, who has argued for years against the prevailing expert view that it is the simple numbers of cattle that drive overgrazing and cause fertile land to become desert. On the contrary, as he has since shown so graphically, the land needs the presence of feeding animals and their droppings for the cycle to be complete, so that soils and grassland areas stay productive. Such that, if you take grazers off the land and lock them away in vast feedlots, the land dies."[68]
The Savory Institute was one of eleven finalists in the Virgin Earth Challenge,[69] a 2007-2019 competition which offered a $25 million prize for whoever could demonstrate a commercially viable design that resulted in the permanent removal of greenhouse gases out of the Earth's atmosphere to contribute materially in global-warming avoidance.[70] None of the entries satisfied all the necessary prize criteria.[71]
Desertification is a type of gradual land degradation of fertile land into arid desert due to a combination of natural processes and human activities.
Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature reserves. It can also be caused by immobile, travel restricted populations of native or non-native wild animals.
A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on Earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area.
In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to free range and consume wild vegetations in order to convert the otherwise indigestible cellulose within grass and other forages into meat, milk, wool and other animal products, often on land that is unsuitable for arable farming.
Rangelands are grasslands, shrublands, woodlands, wetlands, and deserts that are grazed by domestic livestock or wild animals. Types of rangelands include tallgrass and shortgrass prairies, desert grasslands and shrublands, woodlands, savannas, chaparrals, steppes, and tundras. Rangelands do not include forests lacking grazable understory vegetation, barren desert, farmland, or land covered by solid rock, concrete, or glaciers.
Land management is the process of managing the use and development of land resources. One aim of sustainable land management is to prevent or reverse land degradation. Another aim is to ensure water security by increasing soil moisture availability, decreasing surface runoff, and decreasing soil erosion. Land resources are used for a variety of purposes which may include for example agriculture, forestry, water resource management, human settlements and tourism. Unsustainable land managements leads to land being over- or misused which in turn degrades the land, reduces productivity and disrupts natural equilibriums.
Prairie restoration is a conservation effort to restore prairie lands that were destroyed due to industrial, agricultural, commercial, or residential development. The primary aim is to return areas and ecosystems to their previous state before their depletion.
Josh Tickell is an American film director who specializes in movies with a social message. His first feature movie, Fuel won the Sundance Audience Award for Best Documentary, was released theatrically in the United States and became a global sensation gaining over 1 million viewers on Netflix, iTunes, Hulu and CNBC. The movie was screened in the White House for energy and environment staff working in the Obama administration.
Conservation grazing or targeted grazing is the use of semi-feral or domesticated grazing livestock to maintain and increase the biodiversity of natural or semi-natural grasslands, heathlands, wood pasture, wetlands and many other habitats. Conservation grazing is generally less intensive than practices such as prescribed burning, but still needs to be managed to ensure that overgrazing does not occur. The practice has proven to be beneficial in moderation in restoring and maintaining grassland and heathland ecosystems. Conservation or monitored grazing has been implemented into regenerative agriculture programs to restore soil and overall ecosystem health of current working landscapes. The optimal level of grazing and grazing animal will depend on the goal of conservation. Different levels of grazing, alongside other conservation practices, can be used to induce desired results.
Range Condition Scoring was developed as a way to quantify biodiversity in a given rangeland system. This practice is widely used in the Sand Hills region of Nebraska, as well as the tallgrass prairie regions, as evidenced by the authoritative book on the subject, "Range Judging Handbook and Contest Guide for Nebraska." This book outlines the steps required to evaluate, or score, a particular region of rangeland; and it serves as a baseline for the understanding of this method of judging rangeland health.
Holistic Management in agriculture is an approach to managing resources that was originally developed by Allan Savory for grazing management., Holistic Management has been likened to "a permaculture approach to rangeland management". Holistic Management is a registered trademark of Holistic Management International. It has faced criticism from many researchers who argue it is unable to provide the benefits claimed.
Holistic Management International (HMI) is a not-for-profit organization promoting holistic management in agriculture, based in Albuquerque, New Mexico. It maintains an international network of educators and "land stewards" who "use holistic management strategies to manage more than 30 million acres around the globe". HMI's mission is to envision and realize healthy, resilient lands and thriving communities by serving people in the practice of Holistic Decision Making & Management.
The Mu Us Desert, also known as the Maowusu Desert, is a desert in the northern Ordos Plateau in Inner Mongolia, Northwest China. Its southeastern end is crossed by the Ming Great Wall, and it forms the southern portion of the Ordos Desert. The Wuding River drains the area, and then flows into the Ordos Loop of the Yellow River.
Regenerative agriculture is a conservation and rehabilitation approach to food and farming systems. It focuses on topsoil regeneration, increasing biodiversity, improving the water cycle, enhancing ecosystem services, supporting biosequestration, increasing resilience to climate change, and strengthening the health and vitality of farm soil.
Soil regeneration, as a particular form of ecological regeneration within the field of restoration ecology, is creating new soil and rejuvenating soil health by: minimizing the loss of topsoil, retaining more carbon than is depleted, boosting biodiversity, and maintaining proper water and nutrient cycling. This has many benefits, such as: soil sequestration of carbon in response to a growing threat of climate change, a reduced risk of soil erosion, and increased overall soil resilience.
Grassland accounts for China’s largest land resource, covering nearly 41 percent of the national land area. Grassland in the Chinese context comprises widely varying eco-types ranging from the meadows and forest steppes of former Manchuria in the Northeast; and the high, alpine pastures of the Qinghai-Tibetan plateau; to the (semi)arid steppes and deserts in China’s Great West. Due to this geographical and ecological variety, the utilization of grassland is not limited to grazing and forage production, but extends to the exploitation of grassland and forest by-products, as well as the exploitation of mineral resources. Of the total of around 393 million hectares of grassland in China, 84 percent or 331 million hectares is deemed usable for grazing.
Woody plant encroachment is a natural phenomenon characterised by the area expansion and density increase of woody plants, bushes and shrubs, at the expense of the herbaceous layer, grasses and forbs. It refers to the expansion of native plants and not the spread of alien invasive species. Woody encroachment is observed across different ecosystems and with different characteristics and intensities globally. It predominantly occurs in grasslands, savannas and woodlands and can cause regime shifts from open grasslands and savannas to closed woodlands.
Carbon farming is a set of agricultural methods that aim to store carbon in the soil, crop roots, wood and leaves. The technical term for this is carbon sequestration. The overall goal of carbon farming is to create a net loss of carbon from the atmosphere. This is done by increasing the rate at which carbon is sequestered into soil and plant material. One option is to increase the soil's organic matter content. This can also aid plant growth, improve soil water retention capacity and reduce fertilizer use. Sustainable forest management is another tool that is used in carbon farming. Carbon farming is one component of climate-smart agriculture. It is also one way to remove carbon dioxide from the atmosphere.
Desertification in Africa is a form of land degradation that involves the conversion of productive land into desert or arid areas. This issue is a pressing environmental concern that poses a significant threat to the livelihoods of millions of people in Africa who depend on the land for subsistence. Geographical and environmental studies have recently coined the term desertification. Desertification is the process by which a piece of land becomes a desert, as the word desert implies. The loss or destruction of the biological potential of the land is referred to as desertification. It reduces or eliminates the potential for plant and animal production on the land and is a component of the widespread ecosystem degradation. Additionally, the term desertification is specifically used to describe the deterioration of the world's drylands, or its arid, semi-arid, and sub-humid climates. These regions may be far from the so-called natural or climatic deserts, but they still experience irregular water stress due to their low and variable rainfall. They are especially susceptible to damage from excessive human land use pressure. The causes of desertification are a combination of natural and human factors, with climate change exacerbating the problem. Despite this, there is a common misconception that desertification in Africa is solely the result of natural causes like climate change and soil erosion. In reality, human activities like deforestation, overgrazing, and unsustainable agricultural practices contribute significantly to the issue. Another misconception is that, desertification is irreversible, and that degraded land will forever remain barren wastelands. However, it is possible to restore degraded land through sustainable land management practices like reforestation and soil conservation. A 10.3 million km2 area, or 34.2% of the continent's surface, is at risk of desertification. If the deserts are taken into account, the affected and potentially affected area is roughly 16.5 million km2 or 54.6% of all of Africa. 5.7 percent of the continent's surface is made up of very severe regions, 16.2 percent by severe regions, and 12.3 percent by moderate to mild regions.
↑ Briske, David D.; Ash, Andrew J.; Derner, Justin D.; Huntsinger, Lynn (2014). "Commentary: A critical assessment of the policy endorsement for holistic management". Agricultural Systems. 125: 50–53. doi:10.1016/j.agsy.2013.12.001.
↑ Voisin, André (1 December 1988) [1959]. Grass Productivity. Island Press. ISBN978-0933280649. Savory wrote the introduction for the Island Press edition.
1 2 Garnett, Tara; Godde, Cécile (2017). "Grazed and confused?"(PDF). Food Climate Research Network. p.64. Retrieved 11 February 2021. The non-peer-reviewed estimates from the Savory Institute are strikingly higher – and, for all the reasons discussed earlier (Section 3.4.3), unrealistic.
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