Saturday, 19 January 2013

Contradictions Inherent to Human Existence


Contradictions Inherent to Human Existence
Summary: Contradictions are inherent to human existence because of inbuilt contradictions among human needs. Contradictions give rise to conflicts and in order to keep existence, conflicts demand amicable intellectual resolution. One should not be unduly worried about contradictions and conflicts one faces in the due course of life.
We have been generally taught that food, clothing and shelter are basic human needs. It is generally assumed that satisfaction of these needs is all that is required for peaceful and happy life. This may generally be true among have nots in resource deficient environments. But among people with sufficient material resources satisfaction of these needs is insufficient to meet their ends.
All human beings besides having material and biological needs have other needs in the form of interests, sentiments and relationships.
 Interests generally refer to material goals and objectives of human living and may be rooted in other human needs for example a man in need of food is interested in getting food. Interests may also be contextual or culturally determined as generally accepted material entitlements. Interests may be protected by law and then interests are known as rights. Interests may be short term interests such as need for entertainment or long term interests such as the need to conserve relationships, carrier, business establishment, capital etc. Quite often there may be a conflict between short term interests and long term interests.
Sentiments or emotions are protective reflexes that direct action at a distance and thus have a directive influence on human needs. For example sight of the food you relish shall have a directive influence on your appetite and shall make you act to grab the food. The best case on this point is probably parental instinct leading to parental care and survival of species. Sentiments often influence our decisions regarding situations we want to get into or get away from and thus have a directive influence on our wants and desires. Sentiments are ephemeral in character, changing with changing mood, time, place etc. Sentiments may often be in conflict with long term interests.
Relationships are incidental to human need to live in groups such as family, society, work organizations etc. We have a vast variety of relationships such as father, mother, son, daughter, husband etc. Each and every relationship is unique in being governed by particular rules of relationship. In any relationship rules of the particular relationship prevail over self-interest and therefore a relationship demands commitment to rules governing the particular relationship. Relationships are long term phenomena and rules governing particular relationships generally do not vary with time and place.  Emotionally wholesome environment (entertainment) facilitates easy compliance with rules of relationship but any relationship can be satisfied only by commitment to rules of relationship. Therefore in a relationship, commitment prevails over sentiments and self-interests.
It is self-evident that human needs are diverse; therefore conflicts and contradictions are liable to arise at any point in time and space within an individual or between individuals. Short term pleasures can often be in conflict with long term prudence and pragmatism. Short term sentiments and self-interests can often run contrary to long term relationships. The opposite can also happen that for the sake of long term interests, short term needs are sacrificed. But one thing is certain that conflicts and contradictions are inherent to human existence and an individual has to relentlessly negotiate through.
Conflicts and contradictions being inherent to human condition demands provision for efficient conflict resolution mechanisms with sufficient resilience. We can’t sleep over conflicts or indulge in self-denial or self-deprivation. Conflicts often demand intellectual resolution to the greatest satisfaction of various concerns. Bullying, hegemony, self-denial, authoritarianism, self-deprivation, etc. should be avoided for the sake of mentally healthy individuals and healthy societies. Suppression of normal needs, wants and desires is not good for long term health of a society. Conflict resolution is a perpetual balancing act and we have to constantly act to keep the dynamic equilibrium, individually as well as collectively.
It demands that people adopt a life style (system of living) so that it is generally capable of meeting their short term as well as long term needs, interests, sentiments, relationships etc. Life style should be stable, progressive, well adapted to living conditions as well as adaptable to changing facts and circumstances. The life style should be capable of meeting any destabilizing influences i.e. conflicts and contradictions of diverse origin. This would also demand sufficient resilience within the system of living. So the life style is not only well adapted to living conditions but is also adaptable to future conditions. In any well organized system of living, an individual conflict or contradiction is a tiny fraction of the whole and therefore should not a cause to worry about.
There is also need to design a self-perpetuating sustainable culture which can naturally and organically take care of various human needs. It should have efficient conflict resolution mechanisms to ensure its adaptability to various challenges in the face of perpetual struggle for survival. Authoritarianism, egocentricity, will to dominate; hegemony can’t have a place in a sustainable culture.      
Lastly individuals as well as societies should not only be adapted to conditions of their existence but should also be adaptable to ever changing conditions of their existence. The issue is not existence of inherent conflicts; rather the issue is how effectively we deal with them. It demands a perpetual balancing act to sustain the dynamic equilibrium incidental to existence of an individual as well as any human society.
Author: Dr Mahesh C. Jain is a practicing medical doctor and has written the book “Encounter of Science with Philosophy – A synthetic view”. The book begins with first chapter devoted to scientifically valid concept of God and then explains cosmic phenomena right from origin of nature and universe up to origin of life and evolution of man. The book includes several chapters devoted to auxiliary concepts and social sciences as corollaries to the concept of God. This is the only book which deals with origin of nature and universe from null or Zero or nothing. 37th chapter of the book deals with Philosophy of Living.
http://curatio.in

Sunday, 13 January 2013

Origin of Life What is Wrong with RNA World Hypothesis


 Origin of Life: What is Wrong with RNA World Hypothesis

Summary: RNA world hypothesis about origin of life was based on known properties of RNA but in formulating this hypothesis, limitations of RNA as a molecule capable of independently supporting life like activities were overlooked. These limitations are pointed out and DNA is suggested as the more plausible alternative.
The phrase "RNA World" was first used by Nobel laureate Walter Gilbert in 1986, in a commentary on recent observations of the catalytic properties of various forms of RNA.
The RNA world hypothesis is supported by RNA's ability to store, transmit, and duplicate genetic information, as DNA does. RNA can act as a ribozyme, a special type of enzyme. Because it can perform the tasks of both DNA and enzymes, RNA is believed to have once been capable of supporting independent life forms. Some viruses use RNA as their genetic material, rather than DNA.
RNA world hypothesis is further supported by computational ability of RNA. All the three i.e. DNA, RNA and Peptides have been shown to possess computational ability.
 RNA computing has been used to find solutions to Knight Problem in chess. 1024 strands were used. RNA computing correctly identified 43 out of 512 possible solutions with one error. Considering very high specificity of natural biochemical reactions, error checking and correcting mechanisms must co-exist with RNA computing. This explains need for existence of antisense RNA but at the same time raises doubts about ability of RNA alone to support a living system or life like activity.
Self replicative ability of RNA is not without limitations. Only short RNA molecules have been shown to possess this ability and with a questionable fidelity.  One version, 189-bases long, had fidelity of 98.9% which would mean it would make an exact copy of an RNA molecule as long as itself in one of every eight copies. This 189 base pair ribozyme could polymerize a template of at most 14 nucleotides in length, which is too short for replication. However this level of infidelity and limitation to self replication is far too high for living systems to bear. Just a single mutation affecting just one base pair in the entire genome is known to be catastrophic, therefore the kind of self replication seen under lab conditions does not support RNA world hypothesis.
RNA is much more unstable then DNA. This inherent instability of RNA is a further limitation to the ability of RNA to account for origin of life. Living organisms keep their identity and integrity over eons of time and across a vast number of generations. With no provision for RNA repair mechanisms of the kind seen for DNA in living systems, RNA is inherently incapable of performing this task.
 Autocatalysis: Julius Rebek and his colleagues have shown that in an experimental system containing amino acid adenosine and penta fluorophenyl ester with autocatalyst Amino Adenosine triacid ester variants (AATE variants) wherein a particular AATE variant autocatalysed its own synthesis. Therefore, this experiment demonstrates that nucleic acids were not absolute necessity for initial life like activity. Autocatalytic, autoreplicative property may be regarded as one of the properties of matter. These autocatalysts can give rise to population of entities with heredity which could exhibit mutual competition. By no stretch of imagination the particular AATE variant can be regarded as living. Therefore presence of autoreplicative and autocatalyzing property is insufficient to account for origin of life.
All the properties of RNA which lend credibility to RNA world hypothesis are present in DNA but without the limitations of RNA. Moreover DNA unlike RNA is able to form much longer sequences and is much more stable then RNA (DNA has propensity to spontaneous hydrolytic cleavage @1 per million base pair per day with highly efficient DNA repair mechanisms to maintain the status quo) and thus is not only capable of keeping identity and integrity of the organism but also capable of supporting phenomenon of inheritance. Also only DNA is capable of carrying the amount of information needed to support a living system by virtue of its ability to form long sequences of nucleotide bases.
RNA world hypothesis finds some support due to existence of RNA viruses and viroids which are not dependent on DNA during their entire life cycle. But available evidence indicates that these are able to survive only within eukaryotic cells which further imply that RNA can’t account for origin of life. Since life originated about 4 billion years back whereas origin of eukaryotes has been estimated to be only 1.6 – 2.1 billion years back.
Moreover the lab conditions under which various experiments in support of RNA world hypothesis have been conducted have not been shown to naturally exist. Even the nature of chemistry demonstrated in support of RNA world hypothesis is stochastic and not definitive and deterministic. Definitive and deterministic chemistry is the hall mark of biochemistry with no room for aberrant, random, side reactions.
Therefore life could have originated only as a DNA molecule because DNA is the only molecule capable of independently supporting all life like activities.   
Author: Dr Mahesh C. Jain is a practicing medical doctor and has written the book “Encounter of Science with Philosophy – A synthetic view”. The book begins with first chapter devoted to scientifically valid concept of God and then explains cosmic phenomena right from origin of nature and universe up to origin of life and evolution of man. The book includes several chapters devoted to auxiliary concepts and social sciences as corollaries to the concept of God. This is the only book which deals with origin of nature and universe from null. Twenty-ninth chapter of the book deals with the subject matter of ‘Origin of Life’.
http://curatio.in
 Buy Now



Sunday, 6 January 2013

Darwinism versus Variations in Koala Bear


Darwinism versus Variations in Koala Bear
Summary: Darwinism says that random variations are the drivers of evolution, however geographical variations in Australian Koala point to the contrary. Therefore alternative mechanisms of evolution need to be found.
The koala (Phascolarctos cinereus) is an arboreal herbivorous marsupial native to Australia, and the only extant representative of the family Phascolarctidae.
The koala is found in coastal regions of eastern and southern Australia, from Adelaide to the southern part of Cape York Peninsula. Populations also extend for considerable distances inland in regions with enough moisture to support suitable woodlands.
Koalas have been divided into three subspecies and as a matter of rule individuals from southern cooler climates are larger.
VARIATIONS
 A typical Victorian koala (formerly P. cinereus victor) has longer, thicker fur; is a darker, softer grey, often with chocolate-brown highlights on the back and forearms; and has a more prominently light-colored ventral side and fluffy white ear tufts. Typical and New South Wales koala weights are 12 kg (26 lb) for males and 8.5 kg (19 lb) for females.
 The other extreme are Koalas in tropical and sub-tropical Queensland. In Queensland the koala is smaller (at around 6.5 kg (14 lb) for an average male and just over 5 kg (11 lb) for an average female); a lighter often rather scruffy grey in colour; and has shorter, thinner fur. In Queensland, the koala was previously classified as the subspecies P. cinereus adustus.
 Intermediate forms are found in New South Wales named as P. cinereus cinereus.
 A fourth variation, though not technically a subspecies, is the "golden koala", which has a slight golden tinge to the fur as a result of an absence of the melanin pigment that produces albinism in most other mammalian species.
The variation from one form to another is continuous. There are substantial differences between individual koalas in any given region such as hair colour. Koalas may also have white fur in rare cases due to a recessive gene.
Koala fossils are quite rare, but some have been found in northern Australia dating to 20 million years ago. During this time, the northern half of Australia was rainforest. The fossil record indicates that before 50,000 years ago, giant koalas inhabited the southern regions of Australia. The koala fills the same ecological role as the sloths of South America.
 Koala lives almost entirely on Eucalyptus leaves.  It has firm preferences for particular varieties of eucalypt and these preferences vary from one region to another: in the south Manna Gum, Tasmanian Blue Gum, and Swamp Gum are favoured; Grey Gum and Tallowwood are important in the north, and the ubiquitous River Red Gum of the isolated seasonal swamps and watercourses that meander across the dry inland plains allows the koala to live in surprisingly arid areas. Many factors determine which of the 680 species of eucalypt trees the koala eats.
DISCUSSION
From the above account of geography related variations in Koala size; fur color, length and texture; preference for different species of Eucalyptus trees in different regions it is obvious that 20 million years of existence of Koala in Australia have been insufficient to eliminate those variations. This is true despite there being no isolation and ample opportunities for dispersal and migration. These observations are in accordance with conclusions of J.C. Willis that dispersibility as an aid to invasion of unoccupied grounds is rarely significant for the purpose of evolution and the most cosmopolitan genera lacked such dispersion adaptations.
Darwinism says that evolution advances by accumulation of selected random variations and species come into being by dispersion of ancestral species followed by isolation of various populations followed by evolution of different populations into individual species by further accumulation of variations along divergent lines ultimately leading to origin of species.
However in the case of Koala bear we find:-
1.     Variations are not random, rather they are geography related. Even Darwin admitted that flora and fauna on Galapagos Islands varied according to some geographical rule.
2.     20 million years of existence of Koala bear are neither able to eliminate those differences nor evolve different subspecies into species despite geographical continuity or lack of geographical isolation or absence of any barrier to dispersion.
3.     Variations as well as species identity have been maintained despite geographical continuity.

Hence Darwinism can’t be reconciled with geography related variations in Australian Koala. Therefore Darwinism is not the final word about mechanism of evolution.
  Author: Dr Mahesh C. Jain is a practicing medical doctor and has written the book “Encounter of Science with Philosophy – A synthetic view”. The book begins with first chapter devoted to scientifically valid concept of God and then explains cosmic phenomena right from origin of nature and universe up to origin of life and evolution of man. The book includes several chapters devoted to auxiliary concepts and social sciences as corollaries to the concept of God. This is the only book which deals with origin of nature and universe from null or Zero or nothing.  Chapter 30 of the book is about Evolution of Life wherein author has worked out a new theory about evolution of life.
Visit:http:// www.sciencengod.com
          http://curatio.in
                                                                    Buy Now

Sunday, 30 December 2012

Shall NASA be Able to Re-position an Asteroid


Shall NASA be Able to Re-position an Asteroid?
Summary: NASA has recently announced its intention to capture an asteroid and re-position it close to moon, to be used as space station. However several conditions need to be taken into consideration to accomplish the task and hence it may really not be possible for NASA to meet its stated objectives.
American space agency has recently announced its intention to re-position an asteroid close to moon in an orbit and use it as a space station. NASA has claimed that it has all the technology to accomplish the task. It is expected to serve as a proving ground for hardware and crews en route to larger objects deeper into space.
In April, the Keck Institute for Space Studies at the California Institute of Technology reported its conclusion that a 5, 00,000-kg (1.1-million-lb.) near-Earth asteroid (NEA) could be discovered, tracked, captured and delivered to cislunar space by 2025 at a cost of about $2.65 billion.
Keck concluded that placing a 500-ton asteroid in high lunar orbit could provide a unique, meaningful and affordable destination for astronaut crews in the next decade. This disruptive capability would have a positive impact on a wide range of space exploration interests, which includes developing technology to deflect an asteroid on its way to a disastrous collision with Earth’s atmosphere.
Astronomers on the Keck team estimated that a “low-cost, ground based observation campaign” could identify five or so candidate targets per year in the desired 7-meter-dia. Range.
A spacecraft generating power with large circular “Mickey Mouse” solar arrays would use Xenon-based 10-kw Hall thrusters to spiral out to the desired NEA – firing four at a time, each with a specific impulse of 3,000 sec. As it approaches the target, it would use on board instruments to characterize its shape and rotation, and apply algorithms developed by the Defense Advanced Research Agency to match its spin. Then it would essentially lasso the NEA with a 15-meter dia. “capture bag” that would be clinched tight over the spinning space rock, once the spacecraft and asteroid are tightly secured together, the spacecraft would then de-tumble the combination. The Keck study experts calculate that it would take 300 kg of propellant to stabilize the asteroid.
After that, the spacecraft could use its solar-electric propulsion to work its way into a high lunar orbit or even one of the Earth- Moon Lagrangian points that NASA is studying as way stations that avoid fuel-consuming gravity wells en route to destinations beyond low Earth orbit.
It is well known that all celestial bodies maintain precise elliptical orbits. A circular orbit can easily be understood on the basis of balance of gravitational force of attraction and centrifugal force but elliptical orbits that are precisely maintained over an immense period of time can’t be thus explained. No doubt, Kepler’s laws of planetary motion have sufficient room for elliptical orbits but they only define the conditions that are met and not the mechanisms utilized to meet the conditions. It is implicit even in ‘Kepler’s equal area law’ that elliptical orbit requires mathematically-precise maintenance. There is really no room for a celestial body to wander about its elliptical path. Elliptical orbits, for example, involve precise movement of Earth towards Sun during part of its journey and precise movement of Earth away from Sun during another part of its journey. Not only this, it also involves precise conservation of total energy of a celestial body all the time. Therefore elliptical movement of celestial bodies is quite unlike the pendulum movement which involves total inter-conversion of kinetic energy into potential energy and vice versa. Elliptical orbits of celestial bodies involve mathematically precise partial inter-conversion of kinetic energy and potential energy. We just don’t know as to how celestial bodies conserve their energy, maintain precise elliptical paths, precisely regulate inter-conversion of kinetic energy into potential energy and vice versa; and precisely move towards or away from their Sun.
Re-0positioning an asteroid into a new orbit demands precise understanding of these considerations so that appropriate technology can be developed to meet above stated considerations. However, since astronomers/physicists have never posed these questions to themselves, therefore there can’t be any solutions to these questions either.
Hence, NASA may have the technology to be able to discover, track, capture and deliver an asteroid to cislunar space but it is unlikely to have technology to keep it in cislunar space along a precise mathematically predictable elliptical orbit. This must be true and correct at the present level of understanding and technology development.
Therefore NASA with all its resources is unlikely to be able to re-position an asteroid into a new home. Yet this technology may be useful to deflect an asteroid on its way to a disastrous collision with Earth’s atmosphere.
Author: Dr Mahesh C. Jain is a practicing medical doctor has written the book “Encounter of Science with Philosophy – A synthetic view”. The book begins with first chapter devoted to scientifically valid concept of God and then explains cosmic phenomena right from origin of nature and universe up to origin of life and evolution of man. The book includes several chapters devoted to auxiliary concepts and social sciences as corollaries to the concept of God. This is the only book that deals with origin of nature and universe from null (Zero or nothing). This article is in line with author’s understanding of nature.
Visit:  http//www.sciencengod.com      
          http://curatio.in
  Buy Now

Sunday, 23 December 2012

Whether or Not Horse Evolution Lends Any Credibility to Darwinism



Whether or Not Horse Evolution Lends Any Credibility to Darwinism

Posted by +Mahesh
Summary: Horse series is touted as the strongest evidence in support of Darwin’s mechanism of evolution. However this is not correct. Since, there is no evidence that supports migration of horse ancestors from North America to Asia across Bering Land Bridge.  
The evolution of the horse pertains to the phylogenetic ancestry of the modern horse from the small, dog-sized, forest-dwelling Eohippus over geologic time scales. Paleozoologists have been able to piece together a more complete picture of the modern horse's evolutionary lineage than that of any other animal.
The horse belongs to an order known as Perissodactyla, or "odd-toed ungulates", which all share hooved feet and an odd number of toes on each foot, as well as mobile upper lips and a similar tooth structure. This means that horses share a common ancestry with tapirs and rhinoceroses.
Horse evolution is cited as the best example in support of Darwin’s mechanism of evolution essentially consisting of continuous, gradual evolution by accumulation of random variations over immense periods of time.  In this context, Equidae fossils discovered are said to form a horse series that is consistent with Darwin’s mechanism of evolution.
North America is presumed to be horse’s natural habitat. About 55 million years ago there is supposed to be a dry land in the place where present strait of Bering is. However there is no geological or geographical evidence to support this contention. There are only presumptions. The ancestors of American horses migrated to Asia, later Europe and distant Africa along this “bridge”. Even archeologists cannot find their tracks. Even the timeline of horse migration is different in different references varying from 25 million years to 5 million years. For unknown reasons 30 million years ago horses disappeared from America. No reason for extinction of Equidae family from North America has ever been provided. One of the suppositions is that the sting of some fly was poisonous to horses. Moreover if horses became extinct from North America 25 million years back, then where were the horses left to migrate to Asia along Bering Land Bridge.Only in the 16th century horses were brought to America by conquistadors.

 The Bering Strait is approximately 82 kilometres (51 mi; 44 nmi) wide at its narrowest point, with depth varying between 98 feet (30 m) and 160 feet (49 m).It connects the Chukchi Sea (part of the Arctic Ocean) to the north with the Bering Sea (part of the Pacific Ocean) to the south. This is supposed to have transformed into Bering Land Bridge, several times in the geological and geographical history of Earth to permit migration of flora and fauna across North American and European continents and then to Asia and Africa. Bering Land Bridge is said to be 1000 Km wide from NORTH to SOUTH. However the only reason cited in support of such a contention is compulsion of Biogeography. To quote:
“Some, like the ancient saber-toothed cats, have a recurring geographical range: Europe, Africa, Asia, and North America. The only way they could reach the New World was by the Bering land bridge. Had this bridge not existed at that time, the fauna of the world would be very different.”
There is no independent geological or geographical evidence to support existence of Bering Land Bridge. Hence the only difficult with this presumption is that presumes the fact it has to prove.
Despite an excellent fossil record of the Equidae, there are still many gaps in our evolutionary knowledge. Only the modern horse, zebras, wild asses and donkey survive today, but many other lineages have become extinct over the last 50,000 years. Detailed fossil information on the rate and distribution of new equid species has also revealed that the progression between species was not as smooth and consistent as was once believed. Although some transitions, such as that of Dinohippus to Equus, indeed appear to be gradual progressions, a number of others, such as that of Epihippus to Mesohippus, were relatively abrupt in geologic time, taking place over only a few million years. The change in equids' traits was also not always a "straight line" from Eohippus to Equus: some traits reversed themselves at various points in the evolution of new equid species, such as size and the presence of facial fossae, and only in retrospect can certain evolutionary trends be recognized.
Therefore all the accumulated evidences points only to morphological trends and patterns in Equidae family on empirical basis and are no evidence to conclude any straight line evolution from  from the small, dog-sized, forest-dwelling Eohippus over geologic time scales to modern horse in accordance with Darwin’s Mechanism of Evolution. Hence, the observed evolutionary morphological trends and patterns lend no credibility to Darwin’s mechanism of Evolution. There is no evidence to show that ancestors of modern horse actually migrated to Europe through Bering Strait. In fact extinction of horses in North America 30 million years ago precludes such migration. In fact, all the evidence points to correlations, associations and correspondences; widely rampant in nature and for which no rational explanations are presently available.

Cumulative evidence suggests some other mechanism of evolution other than Darwinism. Observed morphological trends and patterns are nothing more than correlations, associations and correspondences that are commonly seen in our study of nature. Empirical data does not fit into Darwin’s mechanism of evolution.

Author: Dr Mahesh C. Jain is a practicing medical doctor and has written the book “Encounter of Science with Philosophy – A synthetic view”. The book begins with first chapter devoted to scientifically valid concept of God and then explains cosmic phenomena right from origin of nature and universe up to origin of life and evolution of man. The book includes several chapters devoted to auxiliary concepts and social sciences as corollaries to the concept of God. This is the only book which deals with origin of nature and universe from null. Thirtieth chapter of the book deals with the subject matter of ‘Evolution of Life’.
http://curatio.in

Monday, 17 December 2012

Whether or not Global Warming is Real – A View Point


Whether or not Global Warming is Real – A View Point

Summary: It is not disputed that mean temperature of Earth has increased by 0.8° C since the early 20th century. Various factors affecting Earth’s surface temperature have been examined and it is found that no mathematical correlation exists between those factors and Global Warming. It is suggested that Earth dynamically keeps its surface temperature.
 The purpose of this article is not to dispute generally accepted facts or to deny projected effects of Global Warming. The purpose of this article is to examine whether or not evidence that has accumulated is being correctly interpreted. Therefore cumulative evidence is generally presumed to be correct. I have principally relied upon Wikipedia to build up this article.
According to Wikipedia:-
“Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. Warming of the climate system is unequivocal, and scientists are more than 90% certain that it is primarily caused by increasing concentrations of greenhouse gases produced by human activities such as the burning of fossil fuels and deforestation. These findings are recognized by the national science academies of all major industrialized nations.
Climate model projections were summarized in the 2007 Fourth Assessment Report (AR4) by the Intergovernmental Panel on Climate Change (IPCC). They indicated that during the 21st century the global surface temperature is likely to rise a further 1.1 to 2.9 °C (2 to 5.2 °F) for their lowest emissions scenario and 2.4 to 6.4 °C (4.3 to 11.5 °F) for their highest. The ranges of these estimates arise from the use of models with differing sensitivity to greenhouse gas concentrations.”
Wikipedia further states:-
“Global warming controversy
The global warming controversy refers to a variety of disputes, significantly more pronounced in the popular media than in the scientific literature, regarding the nature, causes, and consequences of global warming. The disputed issues include the causes of increased global average air temperature, especially since the mid-20th century, whether this warming trend is unprecedented or within normal climatic variations, whether humankind has contributed significantly to it, and whether the increase is wholly or partially an artifact of poor measurements. Additional disputes concern estimates of climate sensitivity, predictions of additional warming, and what the consequences of global warming will be.
In the scientific literature, there is a strong consensus that global surface temperatures have increased in recent decades and that the trend is caused mainly by human-induced emissions of greenhouse gases. No scientific body of national or international standing disagrees with this view, though a few organizations hold non-committal position.
From 1990–1997 in the United States, conservative think tanks mobilized to undermine the legitimacy of global warming as a social problem. They challenged the scientific evidence.”
The difficulty with Global Warming is that cause-effect relationship between increased temperature and the alleged causes has never been scientifically established. Only certain associated changes have been alleged to be the cause. We are not certain if these associated changes are indeed the culprit. Moreover even these projections are based on empirically generated climate models. This is presumably because we do not yet understand how Earth keeps its climate/temperature. So literature has plenty of mutually contradictory observations, claims and counterclaims. Plenty of positive feedback and negative feedback cycles are known but all put together do not explain as to how Earth keeps its climate/temperature within a range. Attempts to link Earth’s temperature with solar constant and its variations just don’t meet the eye. Solar constant is highest during winters and lowest during summers. Variations in solar constant do not exceed 0.1%. Wikipedia states about Solar Constant as under:-
“Solar output is nearly, but not quite, constant. Variations in total solar irradiance were too small to detect with technology available before the satellite era. Total solar output is now measured to vary (over the last three 11-year sunspot cycles) by approximately 0.1%; see solar variation for details.
The solar constant includes all types of solar radiation, not just the visible light. It is measured by satellite to be roughly 1.361 kilowatts per square meter (kW/m²) at solar minimum and approximately 0.1% greater (roughly 1.362 kW/m²) at solar maximum. The actual direct solar irradiance at the top of the atmosphere fluctuates by about 6.9% during a year (from 1.412 kW/m² in early January to 1.321 kW/m² in early July) due to the Earth's varying distance from the Sun, and typically by much less than 0.1% from day to day. Thus, for the whole Earth (which has a cross section of 127,400,000 km²), the power is 1.740×1017 W, plus or minus 3.5%. The solar constant does not remain constant over long periods of time (see Solar variation), but over a year varies much less than the variation of direct solar irradiance at the top of the atmosphere arising from the ellipticity of the Earth's orbit. The approximate average value cited,1.361 kW/m², is equivalent to 1.952 calories per minute per square centimeter, or 1.952 langleys (Ly)—or, in SI units— about 81.672 kJ/m² per minute.
The Earth receives a total amount of radiation determined by its cross section (π·RE²), but as it rotates this energy is distributed across the entire surface area (4·π·RE²). Hence the average incoming solar radiation, taking into account the angle at which the rays strike and that at any one moment half the planet does not receive any solar radiation, is one-fourth the solar constant (approximately 340 W/m²). At any given moment, the amount of solar radiation received at a location on the Earth's surface depends on the state of the atmosphere, the location's latitude, and the time of day.”
The amount of solar energy Earth receives for sun is sufficient to increase surface temperature beyond 100° C in less than one hour. Moreover amount of energy can’t be correlated with observed weather conditions, being the highest in winters and lowest in summers. Even the extent of variation in solar constant can’t be correlated with rise of Earth’s temperature by 0.8° C during the last century. Moreover it is self-evident that Earth was unable to dissipate energy it receives from Sun; it would have been hot enough that no known life forms except (probably) some kind of Extremophiles could have survived. Even depletion of Ozone layer does not correlate with Global Warming.
 In 2008, total worldwide energy consumption was 474 exajoules (474×1018 J=132,000 TWh). This is equivalent to an average power use of 15 terawatts (1.504×1013 W). This is 0.009% of the amount of energy Earth receives from Sun during any year. Therefore increased energy consumption due to increased human activity can’t account for increase in mean temperature of Earth from 13.9° C to 14.6° C (approximate increase of 5.4%) during past 100 years.
From the above discussion, it is evident that Earth rigorously keeps its temperature and Earth’s temperature bears no direct correlation to amount of energy it receives from sun or released by burning of fuels to meet demands created by increased human activity. Further no cause-effect relationship with accumulation of so called green house gases and Earth’s temperature has been established. Increased concentration (16% to 167% since 1750) of naturally occurring greenhouse gases does not linearly correlate with extent of reported mean temperature change. Same is the case with increased positive radiative forcing.  Increased positive radiative forcing for different naturally occurring greenhouse gases has increased from 0.18 W/square meter to 1.79 W/square meter but bears no correlation with reported temperature increase.
Therefore all that can be said at the moment is that Earth’s surface temperature is the result of dynamic equilibrium which is attained and maintained by a variety of mechanisms having positive and negative feedback loops. So the reported increase in mean temperature of Earth may not be due to alleged accumulation of green house gases or increased human activity but may be the result of shift in dynamic equilibrium. How this dynamic equilibrium is determined, attained and maintained is the key issue to be resolved if we want to understand the reason underlying reported increase in mean temperature of Earth. Empirically worked out climate models are really not of much help because they indicate only association of facts and not the rationale behind those facts. Scientific resolution of problem of Global warming is not possible in the absence of proper understanding of the phenomenon. Last but not the least, nature is self-perpetuating and this invariably is the result of dynamic conservation of status-quo.  
Author: Dr Mahesh C. Jain is a practicing medical doctor and has written the book “Encounter of Science with Philosophy – A synthetic view”. The book begins with first chapter devoted to scientifically valid concept of God and then explains cosmic phenomena right from origin of nature and universe up to origin of life and evolution of man. The book includes several chapters devoted to auxiliary concepts and social sciences as corollaries to the concept of God. This is the only book which deals with origin of nature and universe from null or Zero or nothing. 
http://curatio.in