ජේම්ස් ලව්ලොක්

විකිපීඩියා, නිදහස් විශ්වකෝෂය වෙතින්
වෙත පනින්න: සංචලනය, සොයන්න
James Ephraim Lovelock
උපත 26 July 1919
Hertfordshire, England
පදිංචිය England
ජාතිකත්වය British
ක්ෂේත්‍රය Chemistry, Earth Science
ආයතන Independent researcher
ඉගෙනීම ලත් ශාස්ත්‍ර ශාලාව University of Manchester
London School of Hygiene & Tropical Medicine
University of London
Harvard Medical School
ප්‍රසිද්ධ වන ක්ශේත්‍රය Electron capture detector
Gaia hypothesis
සංගණ්ය ත්‍යාගයන් FRS, 1974
Tswett Medal, 1975
ACS, 1980
WMO Norbert Gerbier Prize, 1988
Dr A.H. Heineken Prize for the Environment, 1990
CBE, 1990
CH, 2003

James Ephraim Lovelock, CH, CBE, FRS (born 26 July 1919) is an independent scientist, author, researcher, environmentalist, and futurist who lives in Devon, in the south west of England. He is known for proposing the Gaia hypothesis, in which he postulates that the Earth functions as a kind of superorganism.

Biography[සංස්කරණය කරන්න]

He was born in Letchworth Garden City in Hertfordshire, England, but moved to London where he was, by his own account, an unhappy pupil at Strand School.[1] He studied chemistry at the University of Manchester, before taking up a Medical Research Council post at the Institute for Medical Research in London[2]. His student status enabled temporary deferment of military service during the Second World War, but he registered as a conscientious objector[3]. He later abandoned this position in the light of Nazi atrocities and tried to enlist for war service, but was told that his medical research was too valuable for this to be considered.

In 1948 Lovelock received a Ph.D. degree in medicine at the London School of Hygiene and Tropical Medicine. Within the United States he has conducted research at Yale, Baylor College of Medicine, and Harvard University[2].

Career[සංස්කරණය කරන්න]

A lifelong inventor, Lovelock has created and developed many scientific instruments, some of which were designed for NASA in its programme of planetary exploration. It was while working as a consultant for NASA that Lovelock developed the Gaia Hypothesis, for which he is most widely known.

In early 1961, Lovelock was engaged by NASA to develop sensitive instruments for the analysis of extraterrestrial atmospheres and planetary surfaces. The Viking program that visited Mars in the late-1970s was motivated in part to determining whether Mars supported life, and many of the sensors and experiments that were ultimately deployed aimed to resolve this issue. During work on a precursor of this program, Lovelock became interested in the composition of the Martian atmosphere, reasoning that many life forms on Mars would be obliged to make use of it (and, thus, alter it). However, the atmosphere was found to be in a stable condition close to its chemical equilibrium, with very little oxygen, methane, or hydrogen, but with an overwhelming abundance of carbon dioxide. To Lovelock, the stark contrast between the Martian atmosphere and chemically-dynamic mixture of that of our Earth's biosphere was strongly indicative of the absence of life on the planet[4]. However, when they were finally launched to Mars, the Viking probes still searched (unsuccessfully) for extant life there.

Lovelock invented the electron capture detector, which ultimately assisted in discoveries about the persistence of CFCs and their role in stratospheric ozone depletion[5][6][7]. After studying the operation of the Earth's sulfur cycle[8], Lovelock and his colleagues developed the CLAW hypothesis as a possible example of biological control of the Earth's climate[9].

Lovelock was elected a Fellow of the Royal Society in 1974. He served as the president of the Marine Biological Association (MBA) from 1986 to 1990, and has been a Honorary Visiting Fellow of Green Templeton College, Oxford (formerly Green College, Oxford) since 1994. He has been awarded a number of prestigious prizes including the Tswett Medal (1975), an ACS chromatography award (1980), the WMO Norbert Gerbier Prize (1988), the Dr A.H. Heineken Prize for the Environment (1990) and the RGS Discovery Lifetime award (2001). He became a CBE in 1990, and a Companion of Honour in 2003.

An independent scientist, inventor, and author, Lovelock works out of a barn-turned-laboratory in Devon.

CFCs[සංස්කරණය කරන්න]

Reconstructed time-series of atmospheric concentrations of CFC-11[10].

After the development of his electron capture detector, in the late 1960s, Lovelock was the first to detect the widespread presence of CFCs in the atmosphere[5]. He found a concentration of 60 parts per trillion of CFC-11 over Ireland and, in a partially self-funded research expedition in 1972, went on to measure the concentration of CFC-11 from the northern hemisphere to the Antarctic aboard the research vessel RRS Shackleton[6][11]. He found the gas in each of the 50 air samples that he collected but, not realising that the breakdown of CFCs in the stratosphere would release chlorine that posed a threat to the ozone layer, concluded that the level of CFCs constituted "no conceivable hazard"[11]. He has since stated that he meant "no conceivable toxic hazard".

However, the experiment did provide the first useful data on the ubiquitous presence of CFCs in the atmosphere. The damage caused to the ozone layer by the photolysis of CFCs was later discovered by Frank Rowland and Mario Molina. After hearing a lecture on the subject of Lovelock's results[12], they embarked on research that resulted in the first published paper that suggested a link between stratospheric CFCs and ozone depletion in 1974, and later shared the 1995 Nobel Prize in Chemistry for their work[13].

Gaia[සංස්කරණය කරන්න]

First formulated by Lovelock during the 1960s as a result of work for NASA concerned with detecting life on Mars[14], the Gaia hypothesis proposes that living and non-living parts of the earth form a complex interacting system that can be thought of as a single organism[15][16]. Named after the Greek goddess Gaia, the hypothesis postulates that the biosphere has a regulatory effect on the Earth's environment that acts to sustain life.

While the Gaia Hypothesis was readily accepted by many in the environmentalist community, it has not been fully accepted within the scientific community. Among its more famous critics are the evolutionary biologists Richard Dawkins and Ford Doolittle. These (and other) critics have questioned how natural selection operating on individual organisms can lead to the evolution of planetary-scale homeostasis.[17]

Lovelock has responded to these criticisms with models such as Daisyworld, that illustrate how individual-level effects can translate to planetary homeostasis. However, as Earth Systems Science is still in its infancy, it is not yet clear how well Daisyworld applies to the full complexity of the Earth's biosphere and climate. For instance, climatologists believe that the models used by Lovelock[18] were overly-sensitive to organisms[තහවුරු කරන්න].

Nuclear power[සංස්කරණය කරන්න]

Lovelock has become concerned about the threat of global warming from the greenhouse effect. In 2004 he caused a media sensation when he broke with many fellow environmentalists by pronouncing that "only nuclear power can now halt global warming". In his view, nuclear energy is the only realistic alternative to fossil fuels that has the capacity to both fulfill the large scale energy needs of mankind while also reducing greenhouse emissions. He is an open member of Environmentalists for Nuclear Energy.

In 2005, against the backdrop of renewed UK government interest in nuclear power, Lovelock again publicly announced his support for nuclear energy, stating, "I am a Green, and I entreat my friends in the movement to drop their wrongheaded objection to nuclear energy"[19]. Although these interventions in the public debate on nuclear power are recent, his views on it are longstanding. In his 1988 book The Ages of Gaia he states:

"I have never regarded nuclear radiation or nuclear power as anything other than a normal and inevitable part of the environment. Our prokaryotic forebears evolved on a planet-sized lump of fallout from a star-sized nuclear explosion, a supernova that synthesised the elements that go to make our planet and ourselves."[11]

In The Revenge of Gaia[20] (2006), where he puts forward the concept of sustainable retreat, Lovelock writes:

"A television interviewer once asked me, 'But what about nuclear waste? Will it not poison the whole biosphere and persist for millions of years? ' I knew this to be a nightmare fantasy wholly without substance in the real world... One of the striking things about places heavily contaminated by radioactive nuclides is the richness of their wildlife. This is true of the land around Chernobyl, the bomb test sites of the Pacific, and areas near the United States' Savannah River nuclear weapons plant of the Second World War. Wild plants and animals do not perceive radiation as dangerous, and any slight reduction it may cause in their lifespans is far less a hazard than is the presence of people and their pets... I find it sad, but all too human, that there are vast bureaucracies concerned about nuclear waste, huge organisations devoted to decommissioning power stations, but nothing comparable to deal with that truly malign waste, carbon dioxide."

On 30 May 2006, Lovelock told the Australian Lateline television program: "Modern nuclear power stations are useless for making bombs"[21]. This view may be based on fact that plutonium-239 from the nuclear reactor of a power plant is contaminated with a significant amount of plutonium-240, complicating its use in nuclear weapons[22]. It is easier to enrich uranium than to separate 240Pu from 239Pu to produce weapons-grade material, although even reactor-grade plutonium can in fact be used in weapons eg. dirty bombs[23][24]. Friends of the Earth Australia responded: "Lovelock's claim that nuclear power plants cannot be used for weapons production is false, irresponsible and dangerous. A typical nuclear power reactor produces about 300 kilograms of plutonium each year, enough for 30 nuclear weapons"[21].

Climate and mass human mortality[සංස්කරණය කරන්න]

Writing in the British newspaper The Independent in January 2006, Lovelock argues that, as a result of global warming, "billions of us will die and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable" by the end of the 21st century[25]. He has been quoted in The Guardian that 80% of humans will perish by 2100 AD, and this climate change will last 100,000 years.

He further predicts, the average temperature in temperate regions will increase by as much as 8°C and by up to 5°C in the tropics, leaving much of the world's land uninhabitable and unsuitable for farming, with northerly migrations and new cities created in the Arctic. He predicts much of Europe will become uninhabitable having turned to desert and Britain will become Europe's "life-raft" due to Britain's stable temperature from being surrounded by the ocean. He suggests that "we have to keep in mind the awesome pace of change and realise how little time is left to act, and then each community and nation must find the best use of the resources they have to sustain civilisation for as long as they can"[25].

He partly retreated from this position in a September 2007 address to the World Nuclear Association's Annual Symposium, suggesting that climate change would stabilise and prove survivable, and that the Earth itself is in "no danger" because it would stabilise in a new state. Life, however, might be forced to migrate en masse to remain in habitable climes[26].

Ocean Pipes proposal[සංස්කරණය කරන්න]

In September 2007, Lovelock and Chris Rapley proposed the construction of ocean pipes "100 to 200 metres long, 10 metres in diameter and with a one-way flap valve at the lower end for pumping by wave movement" to pump water up from below the thermocline to "fertilize algae in the surface waters and encourage them to bloom"[27]. The intention of this scheme is to accelerate the transfer of carbon dioxide from the atmosphere to the ocean by increasing primary production and enhancing the export of organic carbon (as marine snow) to the deep ocean. The idea is theoretical, and the authors note that it "may fail, perhaps on engineering or economic grounds", and that "the impact on ocean acidification will need to be taken into account".

The proposal attracted widespread media attention[28][29][30][31], although also criticism[32][33][34]. Commenting on the proposal, Corinne Le Quéré, a University of East Anglia researcher, said "It doesn’t make sense. There is absolutely no evidence that geoengineering options work or even go in the right direction. I’m astonished that they published this. Before any geoengineering is put to work a massive amount of research is needed – research which will take 20 to 30 years"[28]. Other researchers have claimed that "this scheme would bring water with high natural pCO2 levels (associated with the nutrients) back to the surface, potentially causing exhalation of CO2"[34].

A similar scheme to that proposed by Lovelock and Rapley is already being developed by a commercial company[35].

Books[සංස්කරණය කරන්න]

  • Lovelock, James (2000) [1979]. Gaia: A New Look at Life on Earth (3rd ed. සංස්.). Oxford University Press. ISBN 0-19-286218-9. 
  • Lovelock, James; Michael Allaby (1983). Great Extinction. Doubleday. ISBN 0-385-18011-X. 
  • Lovelock, James; Michael Allaby (1984). The Greening of Mars. Warner Books. ISBN 0-446-32967-3. 
  • Lovelock, James (1995) [1988]. Ages of Gaia. Oxford University Press. ISBN 0-393-31239-9. 
  • Lovelock, James (2001) [Gaia Books 1991]. Gaia: The Practical Science of Planetary Medicine. Oxford University Press US. ISBN 0-19-521674-1. 
  • Lovelock, James (1991). Scientists on Gaia. Cambridge, Mass., USA: MIT Press. ISBN 0-262-19310-8. 
  • Lovelock, James (2005). Gaia: Medicine for an Ailing Planet. Gaia Books. ISBN 1-85675-231-3. 
  • Lovelock, James (2000). Homage to Gaia: The Life of an Independent Scientist. Oxford University Press. ISBN 0-19-860429-7.  (Lovelock's autobiography)
  • Lovelock, James (2006). The Revenge of Gaia: Why the Earth Is Fighting Back - and How We Can Still Save Humanity. Santa Barbara (California): Allen Lane. ISBN 0-7139-9914-4. 
  • Lovelock, James (2009). The Vanishing Face of Gaia: A Final Warning: Enjoy It While You Can. Allen Lane. ISBN 978-1846141850. 

References[සංස්කරණය කරන්න]

  1. Homage to Gaia
  2. 2.0 2.1 Biography of James Lovelock, Association of Environmentalists For Nuclear Energy. Retrieved 30 October 2007.
  3. James Lovelock: The green man, Ian Irvine, The Independent, 3 December 2005. Retrieved 14 May 2008.
  4. Lovelock, J.E. (1968). A Physical Basis for Life Detection Experiments. Nature 207, 568-570.
  5. 5.0 5.1 Lovelock, J.E. (1971). Atmospheric Fluorine Compounds as Indicators of Air Movements. Nature 230, 379.
  6. 6.0 6.1 Lovelock, J.E., Maggs, R.J. and Wade, R.J. (1973). Halogenated Hydrocarbons in and over the Atlantic. Nature 241, 194-196.
  7. Travels with an Electron Capture Detector, acceptance speech for Blue Planet Prize 1997
  8. Lovelock, J.E., Maggs, R.J. and Rasmussen, R.A. (1972). Atmospheric Dimethyl Sulphide and the Natural Sulphur Cycle. Nature 237, 452-453.
  9. Charlson, R. J., Lovelock, J. E., Andreae, M. O. and Warren, S. G. (1987). Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate. Nature 326, 655-661.
  10. Walker, S.J., Weiss, R.F. and Salameh, P.K. (2000) Reconstructed histories of the annual mean atmospheric mole fractions for the halocarbons CFC-11, CFC-12, CFC-113 and carbon tetrachloride. Journal of Geophysical Research 105, 14285—14296.
  11. 11.0 11.1 11.2 Lovelock, J.E. (1989). The Ages of Gaia. Oxford University Press, Oxford, UK. ISBN 0-19-286090-9.
  12. F. Sherwood Rowland and Mario J. Molina (2000-12-07). "CFC-Ozone Puzzle: Lecture". සම්ප්‍රවේශය 2007-12-10. 
  13. The Nobel Prize in Chemistry 1995 "for ... work in atmospheric chemistry, particularly concerning the formation and decomposition of ozone", Nobel Foundation. Retrieved 9 May 2008.
  14. Lovelock, J.E. (1965). "A physical basis for life detection experiments". Nature 207 (7): 568–570. doi:10.1038/207568a0. 
  15. J. E. Lovelock (1972). "Gaia as seen through the atmosphere". Atmospheric Environment 6 (8): 579–580. doi:10.1016/0004-6981(72)90076-5. 
  16. Lovelock, J.E.; Margulis, L. (1974). "Atmospheric homeostasis by and for the biosphere- The Gaia hypothesis". Tellus 26 (1): 2–10. 
  17. Dawkins, Richard (1999) [1982]. The Extended Phenotype. Oxford University Press. ISBN 0-19-288051-9. 
  18. Lovelock, J.E.; Kump, L.R. (1995). "Weathering and glacial cycles". Nature 373 (6510): 110–110. doi:10.1038/373110b0. 
  19. Nukes Are Green, Nicholas Kristof, The New York Times, 9 April 2005. Retrieved 4 October 2007.
  20. Lovelock, James (2006). The Revenge of Gaia. Reprinted Penguin, 2007. ISBN 978-0-141-02990-0
  21. 21.0 21.1 James Lovelock urged to get his nuclear facts straight, Friends of the Earth, 4 July 2007. Retrieved 4 October 2007.
  22. Reactor-Grade and Weapons-Grade Plutonium in Nuclear Explosives, Canadian Coalition for Nuclear Responsibility. Retrieved 23 November 2007.
  23. Additional information concerning underground nuclear weapon test of reactor-grade plutonium describing a US test, Canadian Coalition for Nuclear Responsibility. Retrieved 23 November 2007.
  24. Lovins, A.B. (1980). Nuclear weapons and power-reactor plutonium. Nature 283, pp. 817-823.
  25. 25.0 25.1 The Earth is about to catch a morbid fever that may last as long as 100,000 years, James Lovelock, The Independent, 16 January 2006. Retrieved 4 October 2007.
  26. Lovelock: "Respect the Earth", World Nuclear News, 6 September 2007. Retrieved 4 October 2007.
  27. Lovelock, J.E. and Rapley, C.G. (2007). Ocean pipes could help the Earth to cure itself. Nature 449, 403.
  28. 28.0 28.1 Scientists propose 'plumbing' method to solve crisis of global warming, Lewis Smith, The Times, 26 September 2007. Retrieved 3 October 2007.
  29. James Lovelock's plan to pump ocean water to stop climate change, Roger Highfield, The Daily Telegraph, 26 September 2007. Retrieved 4 October 2007.
  30. Pipes hung in the sea could help planet to 'heal itself', Michael McCarthy, The Independent, 27 September 2007. Retrieved 4 October 2007.
  31. How sea tubes could slow climate change, Alok Jha, The Guardian, 27 September 2007. Retrieved 4 October 2007.
  32. Cold water on global warming plans, Phillip Williamson, The Guardian, 1 October 2007. Retrieved 4 October 2007.
  33. The last green taboo: engineering the planet, Johann Hari, The Independent, 4 October 2007. Retrieved 4 October 2007.
  34. 34.0 34.1 Shepherd, J.G., Inglesias-Rodriguez, D. and Yool, A. (2007). Geo-engineering might cause, not cure, problems. Nature 449, 781.
  35. Biological Ocean Sequestration of සැකිල්ල:CO2 Using Atmocean Upwelling, Atmocean. Retrieved 3 October 2007.

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