Oil depletion

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Oil_depletion

Oil depletion is the decline in oil production of a well, oil field, or geographic area. The Hubbert peak theory makes predictions of production rates based on prior discovery rates and anticipated production rates. Hubbert curves predict that the production curves of non-renewing resources approximate a bell curve. Thus, according to this theory, when the peak of production is passed, production rates enter an irreversible decline.

The United States Energy Information Administration predicted in 2006 that world consumption of oil will increase to 98.3 million barrels per day (15,630,000 m³/d) (mbd) in 2015 and 118 million barrels per day in 2030. With 2009 world oil consumption at 84.4 mbd, reaching the projected 2015 level of consumption would represent an average annual increase between 2009 and 2015 of 2.7% per year.

Resource availability

World proved reserves of crude oil, 1980-2012 (US EIA)

 

Ratio of world proved oil reserves to production, 1980-2011 (UN EIA)

 

Main article: Oil reserves

Earth's natural oil supply is effectively fixed because petroleum is naturally formed far too slowly to be replaced at the rate at which it is being extracted. Over many millions of years, plankton, bacteria, and other plant and animal matter became buried in sediments on the ocean floor. When conditions were right – a lack of oxygen for decomposition, and sufficient depth and temperature of burial – these organic remains were converted into petroleum compounds, while the sediment accompanying them was converted into sandstone, siltstone, and other porous sedimentary rock. When capped by impermeable rocks such as shale, salt, or igneous intrusions, they formed the petroleum reservoirs which are exploited today.

Production decline models

Main article: Hubbert peak theory

For the short and medium-term, oil production decline occurs in a predictable manner based on geological circumstances, governmental policies, and engineering practices. The shape of the decline curve varies depending upon whether one considers a well, a field, or a set of fields. In the longer term, technological developments have defied some of the predictions.

Oil well production decline

Theoretical oil production curve for a well with exponential decline

An individual oil well usually produces at its maximum rate at the start of its life; the production rate eventually declines to a point at which it no longer produces profitable amounts. The shape of the decline curve depends on the oil reservoir and the reservoir drive mechanism. Wells in water-drive and gas-cap drive reservoirs often produce at a near constant rate until the encroaching water or expanding gas cap reaches the well, causing a sudden decline in oil production. Wells in gas solution drive and oil expansion drive reservoirs have exponential or hyperbolic declines: rapid declines at first, then leveling off.

The shape of production curve of an oil well can also be affected by a number of nongeologic factors:

• Well may be restricted by choice by lack of market demand or government regulation. This decreases the rate of decline, but will not change the well's total production significantly.
• Hydraulic fracturing (fracking) or acidizing may be used to cause a sharp spike in production, and may increase the recoverable reserves of a given well.
• The field may undergo a secondary or tertiary recovery project, discussed in the next section.

Oil field production decline

Individual oil wells are typically within multi-well oil fields. As with individual wells, the production curves for oil fields vary depending on geology and how they are developed and produced. Some fields have symmetric bell-shaped production profiles, but it is more common that the period of inclining production is briefer and steeper than the subsequent decline. More than half the production usually occurs after a field has reached a peak or plateau. Production profiles of many fields show distinct peaks, but for giant oil fields, it is more common for production to reach and maintain a plateau before declining. Once a field declines, it usually follows an exponential decline. As this decline levels off, production can continue at relatively low rates. A number of oil fields in the U.S. have been producing for over 100 years.

Oil field production curves can be modified by a number of factors:

• Production may be restricted by market conditions or government regulation.
• A secondary recovery project, such as water or gas injection, can repressurize the field and increase the total recovery.
• the field may undergo an enhanced oil recovery project, such as drilling of wells for injection of solvents, carbon dioxide, or steam. This allows more oil to be coaxed out of the rock, increasing the ultimate production of the field.

Multi-field production decline

Hubbert-theory graph of multiple oil field production

Most oil is found in a small number of very large oil fields. According to Hubbert peak theory, production starts off slowly, rises faster and faster, then slows down and flattens until it reaches a peak, after which production declines. In the late stage, production often enters a period of exponential decline in which the decline becomes less and less steep. Oil production may never actually reach zero, but eventually becomes very low. Factors which can modify this curve include:

• Inadequate demand for oil, which reduces steepness of the curve and pushes its peak into the future.
• Sharp price increases when the production peak is reached, as production fails to meet demand. If price increases cause a sharp drop in demand, a dip in the top of the curve may occur.
• Development of new drilling technology or marketing of unconventional oil can reduce the steepness of the decline as more oil is produced than initially anticipated.

United States production

Oil production in the United States, provided one excludes Alaska, began by following the theoretical Hubbert curve for a few decades but is now deviating strongly from it. U.S. oil production reached a peak in 1970 and by the mid-2000s it had fallen to 1940s levels. In 1950, the United States produced over half the world's oil, but by 2005 that proportion had dropped to about 8%. In 2005, U.S. crude oil imports peaked at a rate twice as high as domestic production; since then, U.S. oil production has increased, and imports have fallen 41%.

The production peak in 1970 was predicted by one of the two projections put forward in 1956 by Hubbert. By 1972 all import quotas and controls on U.S. domestic production had been removed. Despite this, and despite the quadrupling of prices during the 1973 oil crisis, the production decline was not reversed in the lower 48 states until 2009. Crude oil production has since risen sharply from 2009 through 2014, so that the rate of US oil production in October 2014 was 81% higher than the average rate in 2008.

The actual U.S. production curve deviates from Hubbert's 1956 curve in significant ways:

• When oil surpluses created a glut on the market and low prices began causing demand and production curves to rise, regulatory agencies such as the Texas Railroad Commission stepped in to restrain production.
• The curve peaked at a higher rate and sharper point than predicted.
• Production fell after 1970, but started to recover and reached a lower secondary peak in 1988. This occurred because the supergiant Prudhoe Bay field in Alaska was only discovered in 1968, and the Trans-Alaska Pipeline System (TAPS) was not completed until 1977. After 1988, Alaska production peaked and total U.S. production began to decline again. By 2005, Prudhoe Bay had produced over 75% of its oil.
• Production increases in the 2010s

• 

  Texas oil field production decline curve

• 

  Alaska oil production decline curve

• 

  Historical US crude oil production showing initial similarity to a Hubbert curve

• 

  Individual oil well decline curve generated by decline curve analysis software, utilized in petroleum economics to indicate the depletion of oil & gas in a Petroleum reservoir. The Y axis is a log scale. Oil production (green line), and gas production (red line).

• 

  Although US proved oil reserves grew by 3.8 billion barrels in 2011, even after deducting 2.07 billion barrels of production, only 8 percent of the 5.84 billion barrels of the newly booked oil was due to new field discoveries (US EIA)

World oil production

World oil field production curve

 

Further information: Peak oil

The 1970 production peak in the U.S. caused many people to begin to question when the world production peak would occur. The peak of world production is known as Peak oil.

Implications of a world peak

Main article: Implications of peak oil

A peak in oil production could result in a worldwide oil shortage, or it could not even be noticed as demand decreases in conjunction with increased prices. While past shortages stemmed from a temporary insufficiency of supply, crossing Hubbert's Peak would mean that the production of oil would continue to decline, and that demand for these products must be reduced to meet supply. The effects of such a shortage would depend on the rate of decline and the development and adoption of effective alternatives.

Catastrophe

The use of fossil fuels allows humans to participate in takedown, which is the consumption of energy at a greater rate than it is being replaced. The industrial economy is currently heavily dependent on oil as a fuel and chemical feedstock. For example, over 90% of transportation in the United States relies on oil.

Since the 1940s, agriculture has dramatically increased its productivity, due largely to the use of chemical pesticides, fertilizers, and increased mechanisation. This process has been called the Green Revolution. The increase in food production has allowed world population to grow dramatically over the last 50 years. Pesticides rely upon oil as a critical ingredient, and fertilizers require natural gas. Farm machinery also requires oil.

Most or all of the uses of fossil fuels in agriculture can be replaced with alternatives. For example, by far the biggest fossil fuel input to agriculture is the use of natural gas as a hydrogen source for the Haber-Bosch fertilizer-creation process. Natural gas is used simply because it is the cheapest currently available source of hydrogen; were that to change, other sources, such as electrolysis powered by solar energy, could be used to provide the hydrogen for creating fertilizer without relying on fossil fuels.

Oil shortages may force a move to lower input "organic agriculture" methods, which may be more labor-intensive and require a population shift from urban to rural areas, reversing the trend towards urbanisation which has predominated in industrial societies; however, some organic farmers using modern organic-farming methods have reported yields as high as those available from conventional farming, but without the use of fossil-fuel-intensive artificial fertilizers or pesticides.

Another possible effect would derive from modern transportation and housing infrastructure. A large proportion of the developed world's population live in suburbs, a type of low-density settlement designed with the automobile in mind. A movement to deal with this problem early, called "New Urbanism," seeks to develop the suburbs into higher density neighborhoods and use high density, mixed-use forms for new building projects.

Recession

A more modest scenario, assuming a slower rate of depletion or a smoother transition to alternative energy sources, could still cause substantial economic hardship such as a recession or depression due to higher energy prices. Inflation has also been linked to oil price spikes. However, economists disagree on the strength and causes of this association. See Energy crisis.

Rising food prices

Main article: food vs fuel

Rising oil prices cause rising food prices in three ways. First, increased equipment fuel costs drive higher prices. Second, transportation costs increase retail prices. Third, higher oil prices are causing farmers to switch from producing food crops to producing biofuel crops.  Supply and demand suggests if fewer farmers are producing food the price of food will rise.

Replacement

An alternative considered likely by some is that oil will be replaced with renewable energy during the first half of the 21st century. The replacement fuel would likely be hydrogen. A hydrogen economy would then replace the current oil-based economy. Another possible replacement fuel is biogas, which is composed of methane. Methane has boiling point of −161 °C, rather than hydrogen's -252.87 °C, making methane a much easier fuel to condense.

Other people consider that the whole idea of "the hydrogen economy" is flawed. Compressed hydrogen has an energy density of only 5.6 megajoules per liter. Robert Zubrin looks at the practical problems of using hydrogen as an energy storage medium in Energy Victory: Winning the War on Terror by Breaking Free of Oil. He considers that hydrogen is a very poor form of storage, and that batteries, methanol or dimethyl ether would be better. This point is reiterated in Beyond Oil and Gas: The Methanol Economy and in David MacKay's book described below.

Geothermal power is one source of sustainable energy that can produce hydrogen. Note that David MacKay has shown in his book Sustainable Energy: Without the Hot Air that geothermal can only provide a tiny fraction of the world's needs sustainably. In some areas located over geological hotspots (such as Iceland), geothermal makes more sense.

Solar energy is a source of inexhaustible energy. There is more solar energy that reaches the surface of the Earth each hour than the amount of energy consumed by the world in a year. The challenges of using the sun's energy – energy which can be obtained either from wind power or from solar power – is that the energy needs to either be (1) stored in physical form of fuel for when it can be used in the future, or (2) transported directly as electricity, through transmission lines. Neither is dispatchable, as there is no control over when the sun will shine or when the wind will blow. There are, however, concentrated solar power plants using thermal storage that can store energy efficiently for up to 24 hours.

Hippocrates

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Hippocrates

 

Hippocrates of Kos
A conventionalized image in a Roman "portrait" bust (19th-century engraving)
Born	c. 460 BC Kos, Ancient Greece
Died	c. 370 BC (aged approximately 90) Larissa, Ancient Greece
Occupation	Physician
Era	Classical Greece

Hippocrates of Kos (/hɪˈpɒkrətiːz/; Greek: Ἱπποκράτης ὁ Κῷος, translit. Hippokrátēs ho Kôios; c. 460 – c. 370 BC), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history of medicine. He is traditionally referred to as the "Father of Medicine" in recognition of his lasting contributions to the field, such as the use of prognosis and clinical observation, the systematic categorization of diseases, or the formulation of humoural theory. The Hippocratic school of medicine revolutionized ancient Greek medicine, establishing it as a discipline distinct from other fields with which it had traditionally been associated (theurgy and philosophy), thus establishing medicine as a profession.

However, the achievements of the writers of the Hippocratic Corpus, the practitioners of Hippocratic medicine, and the actions of Hippocrates himself were often conflated; thus very little is known about what Hippocrates actually thought, wrote, and did. Hippocrates is commonly portrayed as the paragon of the ancient physician and credited with coining the Hippocratic Oath, which is still relevant and in use today. He is also credited with greatly advancing the systematic study of clinical medicine, summing up the medical knowledge of previous schools, and prescribing practices for physicians through the Hippocratic Corpus and other works.

Biography

Illustration of the story of Hippocrates refusing the presents of the Achaemenid Emperor Artaxerxes, who was asking for his services. Painted by Girodet, 1792.

Historians agree that Hippocrates was born around the year 460 BC on the Greek island of Kos; other biographical information, however, is likely to be untrue.

Soranus of Ephesus, a 2nd-century Greek physician, was Hippocrates' first biographer and is the source of most personal information about him. Later biographies are in the Suda of the 10th century AD, and in the works of John Tzetzes, which date from the 12th century AD. Hippocrates is mentioned in passing in the writings of two contemporaries: Plato, in Protagoras and Phaedrus, and Aristotle's Politics, which date from the 4th century BC.

Soranus wrote that Hippocrates' father was Heraclides, a physician, and his mother was Praxitela, daughter of Tizane. The two sons of Hippocrates, Thessalus and Draco, and his son-in-law, Polybus, were his students. According to Galen, a later physician, Polybus, was Hippocrates' true successor, while Thessalus and Draco each had a son named Hippocrates (Hippocrates III and IV).

Soranus said that Hippocrates learned medicine from his father and grandfather (Hippocrates I), and studied other subjects with Democritus and Gorgias. Hippocrates was probably trained at the asklepieion of Kos, and took lessons from the Thracian physician Herodicus of Selymbria. Plato mentions Hippocrates in two of his dialogues: in Protagoras, Plato describes Hippocrates as "Hippocrates of Kos, the Asclepiad"; while in Phaedrus, Plato suggests that "Hippocrates the Asclepiad" thought that a complete knowledge of the nature of the body was necessary for medicine. Hippocrates taught and practiced medicine throughout his life, traveling at least as far as Thessaly, Thrace, and the Sea of Marmara. Several different accounts of his death exist. He died, probably in Larissa, at the age of 83, 85 or 90, though some say he lived to be well over 100.

Hippocratic theory

It is thus with regard to the disease called Sacred: it appears to me to be nowise more divine nor more sacred than other diseases, but has a natural cause from the originates like other affections. Men regard its nature and cause as divine from ignorance and wonder....

— Hippocrates, On the Sacred Disease

Hippocrates is credited with being the first person to believe that diseases were caused naturally, not because of superstition and gods. Hippocrates was credited by the disciples of Pythagoras of allying philosophy and medicine. He separated the discipline of medicine from religion, believing and arguing that disease was not a punishment inflicted by the gods but rather the product of environmental factors, diet, and living habits. Indeed there is not a single mention of a mystical illness in the entirety of the Hippocratic Corpus. However, Hippocrates did work with many convictions that were based on what is now known to be incorrect anatomy and physiology, such as Humorism.

Ancient Greek schools of medicine were split (into the Knidian and Koan) on how to deal with disease. The Knidian school of medicine focused on diagnosis. Medicine at the time of Hippocrates knew almost nothing of human anatomy and physiology because of the Greek taboo forbidding the dissection of humans. The Knidian school consequently failed to distinguish when one disease caused many possible series of symptoms. The Hippocratic school or Koan school achieved greater success by applying general diagnoses and passive treatments. Its focus was on patient care and prognosis, not diagnosis. It could effectively treat diseases and allowed for a great development in clinical practice.

Hippocratic medicine and its philosophy are far removed from that of modern medicine. Now, the physician focuses on specific diagnosis and specialized treatment, both of which were espoused by the Knidian school. This shift in medical thought since Hippocrates' day has caused serious criticism over their denunciations; for example, the French doctor M. S. Houdart called the Hippocratic treatment a "meditation upon death".

Analogies have been drawn between Thucydides' historical method and the Hippocratic method, in particular the notion of "human nature" as a way of explaining foreseeable repetitions for future usefulness, for other times or for other cases.

Crisis

Asklepieion on Kos

An important concept in Hippocratic medicine was that of a crisis, a point in the progression of disease at which either the illness would begin to triumph and the patient would succumb to death, or the opposite would occur and natural processes would make the patient recover. After a crisis, a relapse might follow, and then another deciding crisis. According to this doctrine, crises tend to occur on critical days, which were supposed to be a fixed time after the contraction of a disease. If a crisis occurred on a day far from a critical day, a relapse might be expected. Galen believed that this idea originated with Hippocrates, though it is possible that it predated him.

Illustration of a Hippocratic bench, date unknown

Hippocratic medicine was humble and passive. The therapeutic approach was based on "the healing power of nature" ("vis medicatrix naturae" in Latin). According to this doctrine, the body contains within itself the power to re-balance the four humours and heal itself (physis). Hippocratic therapy focused on simply easing this natural process. To this end, Hippocrates believed "rest and immobilization [were] of capital importance". In general, the Hippocratic medicine was very kind to the patient; treatment was gentle, and emphasized keeping the patient clean and sterile. For example, only clean water or wine were ever used on wounds, though "dry" treatment was preferable. Soothing balms were sometimes employed.

Hippocrates was reluctant to administer drugs and engage in specialized treatment that might prove to be wrongly chosen; generalized therapy followed a generalized diagnosis. Generalized treatments he prescribed include fasting and the consumption of a mix of honey and vinegar. Hippocrates once said that "to eat when you are sick, is to feed your sickness". However, potent drugs were used on certain occasions. This passive approach was very successful in treating relatively simple ailments such as broken bones which required traction to stretch the skeletal system and relieve pressure on the injured area. The Hippocratic bench and other devices were used to this end.

One of the strengths of Hippocratic medicine was its emphasis on prognosis. At Hippocrates' time, medicinal therapy was quite immature, and often the best thing that physicians could do was to evaluate an illness and predict its likely progression based upon data collected in detailed case histories.

Professionalism

A number of ancient Greek surgical tools. On the left is a trephine; on the right, a set of scalpels. Hippocratic medicine made good use of these tools.

Hippocratic medicine was notable for its strict professionalism, discipline, and rigorous practice. The Hippocratic work On the Physician recommends that physicians always be well-kempt, honest, calm, understanding, and serious. The Hippocratic physician paid careful attention to all aspects of his practice: he followed detailed specifications for, "lighting, personnel, instruments, positioning of the patient, and techniques of bandaging and splinting" in the ancient operating room. He even kept his fingernails to a precise length.

The Hippocratic School gave importance to the clinical doctrines of observation and documentation. These doctrines dictate that physicians record their findings and their medicinal methods in a very clear and objective manner, so that these records may be passed down and employed by other physicians. Hippocrates made careful, regular note of many symptoms including complexion, pulse, fever, pains, movement, and excretions. He is said to have measured a patient's pulse when taking a case history to discover whether the patient was lying. Hippocrates extended clinical observations into family history and environment. "To him medicine owes the art of clinical inspection and observation."

Direct contributions to medicine

Clubbing of fingers in a patient with Eisenmenger's syndrome; first described by Hippocrates, clubbing is also known as "Hippocratic fingers".

Hippocrates and his followers were first to describe many diseases and medical conditions. He is given credit for the first description of clubbing of the fingers, an important diagnostic sign in chronic lung disease, lung cancer and cyanotic heart disease. For this reason, clubbed fingers are sometimes referred to as "Hippocratic fingers". Hippocrates was also the first physician to describe Hippocratic face in Prognosis. Shakespeare famously alludes to this description when writing of Falstaff's death in Act II, Scene iii. of Henry V.

Hippocrates began to categorize illnesses as acute, chronic, endemic and epidemic, and use terms such as, "exacerbation, relapse, resolution, crisis, paroxysm, peak, and convalescence." Another of Hippocrates' major contributions may be found in his descriptions of the symptomatology, physical findings, surgical treatment and prognosis of thoracic empyema, i.e. suppuration of the lining of the chest cavity. His teachings remain relevant to present-day students of pulmonary medicine and surgery. Hippocrates was the first documented chest surgeon and his findings and techniques, while crude, such as the use of lead pipes to drain chest wall abscess, are still valid.

The Hippocratic school of medicine described well the ailments of the human rectum and the treatment thereof, despite the school's poor theory of medicine. Hemorrhoids, for instance, though believed to be caused by an excess of bile and phlegm, were treated by Hippocratic physicians in relatively advanced ways. Cautery and excision are described in the Hippocratic Corpus, in addition to the preferred methods: ligating the hemorrhoids and drying them with a hot iron. Other treatments such as applying various salves are suggested as well. Today, "treatment [for hemorrhoids] still includes burning, strangling, and excising." Also, some of the fundamental concepts of proctoscopy outlined in the Corpus are still in use. For example, the uses of the rectal speculum, a common medical device, are discussed in the Hippocratic Corpus. This constitutes the earliest recorded reference to endoscopy. Hippocrates often used lifestyle modifications such as diet and exercise to treat diseases such as diabetes, what is today called lifestyle medicine.

Two popular but likely misquoted attributions to Hippocrates are "Let food be your medicine, and medicine be your food" and "Walking is man's best medicine". Both appear to be misquotations, and their exact origins remain unknown.

In 2017, researchers claimed that, while conducting restorations on the Saint Catherine's Monastery in South Sinai, they found a manuscript which contains a medical recipe of Hippocrates. The manuscript also contains three recipes with pictures of herbs that were created by an anonymous scribe.

Hippocratic Corpus

Main article: Hippocratic Corpus

 

A 12th-century Byzantine manuscript of the Oath in the form of a cross

The Hippocratic Corpus (Latin: Corpus Hippocraticum) is a collection of around seventy early medical works collected in Alexandrian Greece. It is written in Ionic Greek. The question of whether Hippocrates himself was the author of any of the treatises in the corpus has not been conclusively answered, but current debate revolves around only a few of the treatises seen as potentially authored by him. Because of the variety of subjects, writing styles and apparent date of construction, the Hippocratic Corpus could not have been written by one person (Ermerins numbers the authors at nineteen). The corpus came to be known by his name because of his fame, possibly all medical works were classified under 'Hippocrates' by a librarian in Alexandria. The volumes were probably produced by his students and followers.

The Hippocratic Corpus contains textbooks, lectures, research, notes and philosophical essays on various subjects in medicine, in no particular order. These works were written for different audiences, both specialists and laymen, and were sometimes written from opposing viewpoints; significant contradictions can be found between works in the Corpus. Notable among the treatises of the Corpus are The Hippocratic Oath; The Book of Prognostics; On Regimen in Acute Diseases; Aphorisms; On Airs, Waters and Places; Instruments of Reduction; On The Sacred Disease; etc.

Hippocratic Oath

Main article: Hippocratic Oath

The Hippocratic Oath, a seminal document on the ethics of medical practice, was attributed to Hippocrates in antiquity although new information shows it may have been written after his death. This is probably the most famous document of the Hippocratic Corpus. Recently the authenticity of the document's author has come under scrutiny. While the Oath is rarely used in its original form today, it serves as a foundation for other, similar oaths and laws that define good medical practice and morals. Such derivatives are regularly taken today by medical graduates about to enter medical practice.

Legacy

Mural painting showing Galen and Hippocrates. 12th century; Anagni, Italy

Although Hippocrates neither founded the school of medicine named after him, nor wrote most of the treatises attributed to him, he is traditionally regarded as the "Father of Medicine". His contributions revolutionized the practice of medicine; but after his death the advancement stalled. So revered was Hippocrates that his teachings were largely taken as too great to be improved upon and no significant advancements of his methods were made for a long time. The centuries after Hippocrates' death were marked as much by retrograde movement as by further advancement. For instance, "after the Hippocratic period, the practice of taking clinical case-histories died out," according to Fielding Garrison.

After Hippocrates, another significant physician was Galen, a Greek who lived from AD 129 to AD 200. Galen perpetuated the tradition of Hippocratic medicine, making some advancements, but also some regressions. In the Middle Ages, the Islamic world adopted Hippocratic methods and developed new medical technologies. After the European Renaissance, Hippocratic methods were revived in western Europe and even further expanded in the 19th century. Notable among those who employed Hippocrates' rigorous clinical techniques were Thomas Sydenham, William Heberden, Jean-Martin Charcot and William Osler. Henri Huchard, a French physician, said that these revivals make up "the whole history of internal medicine."

Image

Engraving: bust of Hippocrates by Paulus Pontius after Peter Paul Rubens, 1638

According to Aristotle's testimony, Hippocrates was known as "The Great Hippocrates". Concerning his disposition, Hippocrates was first portrayed as a "kind, dignified, old country doctor" and later as "stern and forbidding". He is certainly considered wise, of very great intellect and especially as very practical. Francis Adams describes him as "strictly the physician of experience and common sense."

His image as the wise, old doctor is reinforced by busts of him, which wear large beards on a wrinkled face. Many physicians of the time wore their hair in the style of Jove and Asklepius. Accordingly, the busts of Hippocrates that have been found could be only altered versions of portraits of these deities. Hippocrates and the beliefs that he embodied are considered medical ideals. Fielding Garrison, an authority on medical history, stated, "He is, above all, the exemplar of that flexible, critical, well-poised attitude of mind, ever on the lookout for sources of error, which is the very essence of the scientific spirit." "His figure... stands for all time as that of the ideal physician," according to A Short History of Medicine, inspiring the medical profession since his death.

Legends

The Travels of Sir John Mandeville reports (incorrectly) that Hippocrates was the ruler of the islands of "Kos and Lango" [sic], and recounts a legend about Hippocrates' daughter. She was transformed into a hundred-foot long dragon by the goddess Diana, and is the "lady of the manor" of an old castle. She emerges three times a year, and will be turned back into a woman if a knight kisses her, making the knight into her consort and ruler of the islands. Various knights try, but flee when they see the hideous dragon; they die soon thereafter. This is a version of the legend of Melusine.

Namesakes

Statue of Hippocrates in front of the Mayne Medical School in Brisbane

Some clinical symptoms and signs have been named after Hippocrates as he is believed to be the first person to describe those. Hippocratic face is the change produced in the countenance by death, or long sickness, excessive evacuations, excessive hunger, and the like. Clubbing, a deformity of the fingers and fingernails, is also known as Hippocratic fingers. Hippocratic succussion is the internal splashing noise of hydropneumothorax or pyopneumothorax. Hippocratic bench (a device which uses tension to aid in setting bones) and Hippocratic cap-shaped bandage are two devices named after Hippocrates. Hippocratic Corpus and Hippocratic Oath are also his namesakes. Risus sardonicus, a sustained spasming of the face muscles may also be termed the Hippocratic Smile. The most severe form of hair loss and baldness is called the Hippocratic form.

In the modern age, a lunar crater has been named Hippocrates. The Hippocratic Museum, a museum on the Greek island of Kos is dedicated to him. The Hippocrates Project is a program of the New York University Medical Center to enhance education through use of technology. Project Hippocrates (an acronym of "HIgh PerfOrmance Computing for Robot-AssisTEd Surgery") is an effort of the Carnegie Mellon School of Computer Science and Shadyside Medical Center, "to develop advanced planning, simulation, and execution technologies for the next generation of computer-assisted surgical robots." Both the Canadian Hippocratic Registry and American Hippocratic Registry are organizations of physicians who uphold the principles of the original Hippocratic Oath as inviolable through changing social times.

Genealogy

Hippocrates' legendary genealogy traces his paternal heritage directly to Asklepius and his maternal ancestry to Heracles. According to Tzetzes's Chiliades, the ahnentafel of Hippocrates II is:

A mosaic of Hippocrates on the floor of the Asclepieion of Kos, with Asklepius in the middle, 2nd–3rd century

1. Hippocrates II.
2. Heraclides
4. Hippocrates I.
8. Gnosidicus
16. Nebrus
32. Sostratus III.
64. Theodorus II.
128. Sostratus, II.
256. Thedorus
512. Cleomyttades
1024. Crisamis
2048. Dardanus
4096. Sostratus
8192. Hippolochus
16384. Podalirius
32768. Asklepius

Ecosystem-based adaptation

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Ecosystem-based_adaptation 

Ecosystem-based adaptation (EbA) encompasses a broad set of approaches to adapt to climate change. They all involve the management of ecosystems and their services to reduce the vulnerability of human communities to the impacts of climate change. The Convention on Biological Diversity defines EbA as "the use of biodiversity and ecosystem services as part of an overall adaptation strategy to help people to adapt to the adverse effects of climate change".

EbA involves the conservation, sustainable management and restoration of ecosystems, such as forests, grasslands, wetlands, mangroves or coral reefs to reduce the harmful impacts of climate hazards including shifting patterns or levels of rainfall, changes in maximum and minimum temperatures, stronger storms, and increasingly variable climatic conditions. EbA measures can be implemented on their own or in combination with engineered approaches (such as the construction of water reservoirs or dykes), hybrid measures (such as artificial reefs) and approaches that strengthen the capacities of individuals and institutions to address climate risks (such as the introduction of early warning systems).

EbA is nested within the broader concept of nature-based solutions and complements and shares common elements with a wide variety of other approaches to building the resilience of social-ecological systems. These approaches include community-based adaptation, ecosystem-based disaster risk reduction, climate-smart agriculture, and green infrastructure, and often place emphasis on using participatory and inclusive processes and community/stakeholder engagement. The concept of EbA has been promoted through international fora, including the processes of the United Nations Framework Convention on Climate Change (UNFCCC) and the Convention on Biological Diversity (CBD). A number of countries make explicit references to EbA in their strategies for adaptation to climate change and their Nationally Determined Contributions (NDCs) under the Paris Agreement.

While the barriers to widespread uptake of EbA by public and private sector stakeholders and decision makers are substantial, cooperation toward generating a greater understanding of the potential of EbA is well established among researchers, advocates, and practitioners from nature conservation and sustainable development groups. EbA is increasingly viewed as an effective means of addressing the linked challenges of climate change and poverty in developing countries, where many people are dependent on natural resources for their lives and livelihoods.

Overview

Ecosystem-based Adaptation (EbA) describes a variety of approaches for adapting to climate change, all of which involve the management of ecosystems to reduce the vulnerability of human communities to the impacts of climate change such as storm and flood damage to physical assets, coastal erosion, salinisation of freshwater resources, and loss of agricultural productivity. EbA lies at the intersection of climate change adaptation, socio-economic development, and biodiversity conservation (see Figure 1).

While ecosystem services have always been used by societies, the term Ecosystem-based Adaptation was coined in 2008 by the International Union for Conservation of Nature (IUCN) and its member institutions at the UN Climate Change Convention Conference in 2008. EbA was officially defined in 2009 at the UN Convention on Biological Diversity Conference.

Adaptation to climate change hazards

Healthy ecosystems provide important ecosystem services that can contribute to climate change adaptation. For example, healthy mangrove ecosystems provide protection from the impacts of climate change, often for some of the world's most vulnerable people, by absorbing wave energy and storm surges, adapting to rising sea levels, and stabilizing shorelines from erosion. EbA focuses on benefits that humans derive from biodiversity and ecosystem services and how these benefits can be used for managing risk to climate change impacts. Adaptation to climate change is particularly urgent in developing countries and many Small Island Developing States that are already experiencing some of the most severe impacts of climate change, have economies that are highly sensitive to disruptions, and that have lower adaptive capacity.

Making active use of biodiversity and ecosystem services

EbA can involve a wide range of ecosystem management activities that aim to reduce the vulnerability of people to climate change hazards (such as rising sea levels, changing rainfall patterns, and stronger storms) through using nature. For example, EbA measures include coastal habitat restoration in ecosystems such as coral reefs, mangrove forests, and marshes to protect communities and infrastructure from storm surges; agroforestry to increase resilience of crops to droughts or excessive rainfall; integrated water resource management to cope with consecutive dry days and change in rainfall patterns; and sustainable forest management interventions to stabilise slopes, prevent landslides, and regulate water flow to prevent flash flooding (see Table 1).

Co-benefits of EbA

By deploying EbA, proponents cite that many other benefits to people and nature are delivered simultaneously. These correlated benefits include improved human health, socioeconomic development, food security and water security, disaster risk reduction, carbon sequestration, and biodiversity conservation. For example, restoration of ecosystems such as forests and coastal wetlands can contribute to food security and enhance livelihoods through the collection of non-timber forest products, maintain watershed functionality, and sequester carbon to mitigate global warming. Restoration of mangrove ecosystems can help increase food and livelihood security by supporting fisheries, and reduce disaster risk by decreasing wave height and strength during hurricanes and storms.

Implementation and examples of EbA

Examples of EbA measures and outcomes

Particular ecosystems can provide a variety specific climate change adaptation benefits (or services). The most suitable EbA measures will depend on local context, the health of the ecosystem and the primary climate change hazard that needs to be addressed. The below table provides an overview of these factors, common EbA measures and intended outcomes.

Table 1. Examples of EbA measures and outcomes The table shows climate hazards and their potential impacts on people, as well as examples of corresponding EbA measures. Many of the same climate hazards affect different ecosystems and have similar impacts on people, as such, the table illustrates the overlap between impacts, EbA measures and adaptation outcomes. Adapted from the PANORAMA database

Climate change hazards	Potential impacts on people	EbA measures by ecosystem type	Expected outcomes
Erratic rainfall Floods Shift of seasons Temperature increases Drought Extreme heat	Higher flood risks for people and infrastructure; Decrease in agricultural (and livestock) production; Food insecurities; Economic losses and/or insecurities; Threats to human health and well-being; Higher risk of heat strokes Lack of water	Mountains and forests: Sustainable mountain wetland management Forest and pasture restoration Inland waters: Conservation of wetlands and peat lands River basin restoration Trans-boundary water governance and ecosystem restoration Agriculture and drylands: Ecosystem restoration and agroforestry Using trees to adapt to changing seasons Intercropping of adapted species Sustainable livestock management and pasture restoration Sustainable dryland management Urban areas: Green aeration corridors for cities Storm water management using green spaces River restoration in urban areas Green facades for buildings	Improved water regulation; Erosion prevention; Improved water storage capacity; Flood risk reduction; Improved water provisioning; Improved water storage capacity; Adaptation to higher temperatures; Heat wave buffering
Storm surges Cyclones Sea level rise Salinisation Coastal erosion	Higher flood risks for people and infrastructure; Higher storm and cyclone risk for people and infrastructure; Decrease in agricultural (and livestock) production; Food insecurities; Economic losses and/or insecurities; Threats to human health and well-being; Lack of potable water	Marine and coastal: Mangrove restoration and coastal protection Coastal realignment Sustainable fishing and mangrove rehabilitation Coastal reef restoration	Storm and cyclone reduction; Flood risk reduction; Improved water quality; Adaptation to higher temperatures

Principles and standards for implementing EbA

Since the evolution of the concept and practice of EbA, various principles and standards have been developed to guide best practices for implementation. The guidelines adopted by the CBD build on these efforts and include a set of principles to guide planning and implementation. The principles are broadly clustered into four themes:

1. Building resilience and enhancing adaptive capacity through EbA interventions;
2. Ensuring inclusivity and equity in planning and implementation;
3. Consideration of multiple spatial and temporal scales in the design of EbA interventions;
4. Improving the effectiveness and efficiency of EbA, for example, by incorporating adaptive management, identifying limitations and trade-offs, integrating the knowledge of indigenous peoples and local communities.

These principles are complemented by safeguards, which are social and environmental measures to avoid unintended consequences of EbA to people, ecosystems and biodiversity.

Standards have also been developed to help practitioners understand what interventions qualify as EbA, including the elements of helping people adapt to climate change, making active use of biodiversity and ecosystem services, and being part of an overall adaptation strategy.

Challenges to be addressed for greater adoption of EbA

Although interest in Ecosystem-based Adaptation has grown, and meta-analyses of case studies are demonstrating the efficacy and cost-effectiveness of EbA interventions, there are recognised challenges that should be addressed or considered to increase adoption of the approach. These include:

Potential limitations of ecosystem services under a changing climate. One challenge facing EbA is the identification of limits and thresholds beyond which EbA might not deliver adaptation benefits and the extent ecosystems can provide ecosystem services under a changing climate.

Difficulty in monitoring, evaluation, and establishing the evidence base for effective EbA. Confusion around what Ecosystem-based Adaptation means has led to an array of different methodologies used for assessments, and the lack of consistent and comparable quantitative measures of EbA success and failure makes it difficult to argue the case for EbA in socio-economic terms. EbA research has also relied heavily on Western scientific knowledge without due consideration of local and traditional knowledge. In addition, it can be difficult to implement a plan for monitoring and evaluation due to potentially long timescales required to observe the impacts of EbA.

Governance and institutional constraints. Because EbA is a multi-sectoral policy issue, the challenges of governing and planning are immense. This is due in part to the fact that EbA involves both the sectors that manage ecosystems and those that benefit from ecosystem services.

Economic and financial constraints. Broad macroeconomic considerations such as economic development, poverty, and access to financial capital to implement climate adaptation options are contributing factors to constraints impeding greater uptake of EbA. Public and multilateral funding for EbA projects thus far has been available through the International Climate Initiative of the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, the Global Environment Facility, the Green Climate Fund, the European Union, the Department for International Development of the Government of the United Kingdom, the Swedish International Development Cooperation Agency and the Danish International Development Agency, among other sources.

Social and cultural barriers. A clear factor constraining EbA is varying perceptions of risks and cultural preferences for particular types of management approaches such as cultural preferences for what a particular landscape should look like. Potential stakeholders can hold negative perceptions about particular types of EbA strategies.

Policy frameworks

Several international policy fora have acknowledged the multiple roles that ecosystems play in delivering services and addressing global challenges, including those related to climate change, natural disasters, sustainable development, and biodiversity conservation.

Climate change policy

The Paris Agreement explicitly recognises nature's role in helping people and societies address climate change, calling on all Parties to acknowledge "the importance of ensuring the integrity of all ecosystems, including oceans, and the protection of biodiversity, recognised by some cultures as Mother Earth"; its Articles include several references to ecosystems, natural resources and forests.

This notion has translated into high-level national intent, as revealed by comparative analyses of the Nationally Determined Contributions (NDCs) submitted to the UN Framework Convention on Climate Change (UNFCCC) by signatories of the Paris Agreement. The UNFCCC also established the national adaptation plan (NAP) process as a way to facilitate adaptation planning in least developed countries (LDCs) and other developing countries. Because of their lower level of development, climate change risks magnify development challenges for LDCs.

Disaster risk reduction policy

Measures and interventions applied as part of EbA are often closely linked or similar to those employed under ecosystem-based disaster risk reduction (Eco-DRR). The Sendai Framework for Disaster Risk Reduction acknowledges that in order to strengthen disaster risk governance and manage disaster risk and risk reduction at global and regional levels, it is important "to promote transboundary cooperation to enable policy and planning for the implementation of ecosystem-based approaches with regard to shared resources, such as within river basins and along coastlines, to build resilience and reduce disaster risk, including epidemic and displacement risk".

Sustainable development policy

The Sustainable Development Goals (SDGs) are a collection of 17 global goals set by the United Nations General Assembly in 2015. Biodiversity and ecosystems feature prominently across many of the SDGs and associated targets. They contribute directly to human well-being and development priorities. Biodiversity is at the centre of many economic activities, particularly those related to crop and livestock agriculture, forestry, and fisheries. Globally, nearly half of the human population is directly dependent on natural resources for its livelihood, and many of the most vulnerable people depend directly on biodiversity to fulfil their daily subsistence needs. Ecosystem-based Adaptation offers potential to contribute towards the implementation of numerous SDGs, including the goals related to climate adaptation (SDG 13), eliminating poverty and hunger (SDGs 1 and 2), ensuring livelihoods and economic growth (SDG 8) and life on land and life under water (SDGs 14 and 15), among others.

Biodiversity conservation policy

The Strategic Plan for Biodiversity 2011-2020 and the Aichi Biodiversity Targets, under the Convention on Biological Diversity (CBD), aim to halt the loss of biodiversity to ensure ecosystems are resilient and continue to provide essential services. Most recently, the Conference of the Parties has adopted voluntary guidelines for the design and effective implementation of ecosystem-based approaches to adaptation and disaster risk reduction.

EbA and similar approaches have been called for in other policy frameworks, including the United Nations Convention to Combat Desertification (UNCCD) and the Ramsar Convention.

EbA knowledge exchange platforms

The following is an alphabetical list of EbA networks, working groups, and platforms that are exchanging knowledge and experiences in an effort to address and overcome the challenges of implementing EbA. This selection is not exhaustive.

AdaptationCommunity

Coastal EbA

EbA Community

Friends of EbA

International EbA Community of Practice

PANORAMA Solutions – EbA Portal

We Adapt