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| TEMPERATURE CHANGES ON EARTH
  DURING  THE
  PAST 18,000 YEARS FROM 2005 AD  [Contacts]   NOTE:  Data obtained from Internet sources and
  checked with various
  authors for relative accuracy as of 2020   CLICK All
  To Enlarge | 
      
 
 
       DATE APROXIMATIONS                                                                                 DISCUSSION            REFERENCES
 
| 80,000 B.C. ---------  80-40,000 B.C. ----   40,000 B.C. ---------  39,000 B.C. --------   28,000 B.C. ---------  16,000 B.C. ---------  12,000 B.C. ---------  10,000 B.C. ---------   9,000
  B.C. ---------                                   8,000 B.C. ---------   
 5,500 - 6,000 B.C.--  6,000-3,500 B.C.----  4,000 B.C. -----------  1,700 B.C. -----------   1,420 
  B.C. -----------  1,290 1,180 B.C. -- 1,100 B.C. --------       
  597 A.D. ----------   600-700 A.D. -----    
  635 A.D. ----------  c 950-1250
  A.D.
  ----  c 1360-1860
  A.D.
  ---- 1870  2020 ---    | Modern humans appear in southern Africa (judged from jewelry
  production) Several catastrophic climatic changes decimate human population Small group of modern humans cross Red
  Sea to Yemen Artistic cave paintings appear at diverse locations Small carvings of human females appear from Europe through Asia The climate begins to warm Flooding over vast areas of the earth intensifies Development of reliable ocean navigation opened up the world around  Mini Ice Age lasts a few
  hundred years.  Seafarers from Morocco
  and northern  Spain explore entire west coast of Europe.  Caucasian race appears in Libya Ice Age mega fauna goes
  extinct.  Societies become
  more centrally directed.  Specialized trades expand, longevity increases.  Ireland to Scandinavia colonized. Language becomes more organized and developed (See Linguistics) Migrations out of North Africa to points east and north (as desert
  expands)  The Holocene Maximum warm
  period Peteroborough, Canada petroglyphs carved (See Bronze Age) Isle of Thera volcano erupts, devastating Crete & other areas Major attacks by Sea Peoples on Egypt (attempt
  to reestablish Goddess religion) Hebrews leave Egypt Benedictine clerics expand Christian conversion activity in Europe Horsecreek Petroglyph carved in
  West Virginia ? (See Horsecreek) Roman Catholic sponsored Invention of modern European languages
  expanded Medieval Warm Period Little Ice Age Industrial Age , Global Warming   | 
 
|               The Earth has been ice-free (even
  at the poles) for most of its history. 
  However, these iceless periods have been interrupted by several major
  glaciations (called Glacial Epochs)
  and we are in one now in the 21st Century.   Each glacial epoch consists
  of many advances and retreats of ice fields.  These ice fields tend to
  wax and wane in about 100,000, 41,000 and 21,000 year cycles.  Each
  advance of ice has been referred to as an "Ice Age" but it is
  important to realize that these multiple events are just variations of the
  same glacial epoch.  The retreat of ice during a glacial epoch is called
  an Inter-Glacial Period and this is our present climate system.              The existing Plio-Pleistocene
  Glacial Epoch began about 3.2 million years ago and is
  probably linked to the tectonic construction of the Isthmus of Panama which
  prevented the circulation of Atlantic and Pacific waters and eventually triggered
  a slow sequence of events that finally led to cooling of the atmosphere and
  the formation of new ice fields by about 2.5 million years ago.              Thus far, the Earth has had around
  15 to 20 individual major advances and subsequent retreats of the ice field
  in our current Glacial Epoch.  The last major
  advance of glacial ice peaked about 18,000 years ago and since that time the
  ice has generally been retreating although with some short-term interruptions
  (See Graph above). 
  What we are presently experiencing in Greenland and other continents
  is a rapid melting of surrounding sea ice by rising ocean temperatures and a
  widening of the Gulf Stream.  Greenland's continental glaciers are also
  retreating due to an accumulation of atmospheric soot and a reduction of
  fresh snow to cover it.  Oceanic
  islands are vulnerable to inundation by subsequent rising ocean levels and
  destruction of protective coral reefs as a consequence of higher  ocean temperatures.   Abramov, O. & Mojzsis, S. J. Microbial habitability
  of the Hadean Earth during the late heavy bombardment. Nature 459, 419422
  (2009). Allwood, A. C. et al. Stromatolite reef from the early
  Archean era of Australia. Nature 441, 714718 (2006). Anbar, A. D. et al. A whiff of oxygen before the Great
  Oxidation Event? Science 317, 19031906 (2007). Beerling, D. et al. Methane and the CH4-related
  greenhouse effect over the past 400 million years. American Journal of
  Science 309, 97113 (2009). Bekker, A. & Kaufman, A. J. Oxidative forcing of
  global climate change; A biogeochemical record across the oldest
  Paleoproterozoic ice age in North America. Earth and Planetary Science
  Letters 258, 486499 (2007). Bekker, A. et al. Dating the rise of atmospheric oxygen.
  Nature 427, 117120 (2004). Berner, R. A. GEOCARBSULF: A combined model for
  Phanerozoic atmospheric O2 and CO2. Geochimica et Cosmochimica Acta 70,
  56535664 (2006). Berner, R. A. Phanerozoic atmospheric oxygen: New
  results using the GEOCARBSULF model. American Journal of Science 309, 603606
  (2009). Blake, R. E., Chang, S. J. & Lepland, A. Phosphate
  oxygen isotope evidence for a temperate and biologically active Archean
  ocean. Nature 464, 10291033. Brocks, J. J. et al. Archean molecular fossils and the
  early rise of Eukaryotes. Science 285, 10331036 (1999). Byerly, G. R. et al. An Archean impact layer from the
  Pilbara and Kaapvaal cratons. Science 297, 13251327 (2002). Canfield, D. E. & Teske, A. Late Proterozoic rise in
  atmospheric oxygen concentration inferred from phylogenetic and
  sulphur-isotope studies. Nature 382, 127132 (1996). Canfield, D. E., Poulton, S. W. & Narbonne, G. M.
  Late-Neoproterozoic deep-ocean oxygenation and the rise of animal life.
  Science 315, 9295 (2006). Catling, D. C., Zahnle, K. J. & McKay, C. P.
  Biogenic methane, hydrogen escape, and the irreversible oxidation of early
  Earth. Science 293, 839843 (2001). Clayton, R. N., ONeil, J. R. & Mayeda, T. K. Oxygen
  isotope exchange between quartz and water. Journal of Geophysical Research
  77, 30573067 (1972). Des Marais, D. J. et al. Carbon isotope evidence for the
  stepwise oxidation of the Proterozoic environment. Nature 359, 605609
  (1992). Eugster, H. P. Sodium carbonate-bicarbonate minerals as
  indicators of PCO2. Journal of Geophysical Research 71, 33693378 (1966). Evans, D. A. A fundamental PrecambrianPhanerozoic shift
  in Earths glacial style? Tectonophysics 375, 353385 (2003). Evans, D. A., Beukes, N. J. & Kirschvink, J. L.
  Low-latitude glaciations in the Paleoproterozoic era. Nature 386, 262266
  (1997). Farquhar, J., Bao, H. & Thiemans, M. Atmospheric
  influences of Earths earliest sulfur cycle. Science 289, 756758 (2000). Goldblatt, C. & Zahnle, K. J. Clouds and the faint
  young Sun paradox. Climate of the Past 7, 203220 (2011). Goldblatt, C., Lenton, T. M. & Watson, A. J.
  Bistability of atmospheric oxygen and the Great Oxidation. Nature 443,
  683686 (2006). Gough, D. O. Solar interior structure and luminosity
  variations. Solar Physics 74, 2134 (1981). Haqq-Misra, J. D. et al. Revised, hazy methane
  greenhouse for the Archean Earth. Astrobiology 8, 11271137 (2008). Hessler, A. M. & Lowe, D. R. Weathering and sediment
  generation in the Archean: An integrated study of the evolution of
  siliciclastic sedimentary rocks of the 3.2 Ga Moodies Group, Barberton
  Greenstone Belt, South Africa. Precambrian Research 151, 185210 (2006). Hessler, A. M. et al. A lower limit for atmospheric
  carbon dioxide levels 3.2 billion years ago. Nature 428, 736738 (2004). Heubeck, C. An early ecosystem of Archean tidal
  microbial mats (Moodies Group, South Africa, ca. 3.2 Ga). Geology 37, 931934
  (2009). Hofmann, H. J. Precambrian microflora, Belcher Islands,
  Canada: Significance and systematics. Journal of Paleontology 50, 10401073
  (1976). Hofmann, H. J. et al. Origin of 3.45 Ga coniform
  stromatolites in Warrawoona Group, Western Australia. Geological Society of
  America Bulletin 111, 12561262 (1999). Holland, H. D. The oxygenation of the atmosphere and
  oceans. Philosophical Transactions of the Royal Society B: Biological
  Sciences 361, 903915 (2006). Hren, M. T., Tice, M. M. & Chamberlain, C. P. Oxygen
  and hydrogen isotope evidence for a temperate climate 3.42 billion years ago.
  Nature 205, 205208 (2009). Jaffres, J. B. D., Shields, G. A. & Wallmann, K. The
  oxygen isotope evolution of sea water; A critical review of a long standing
  controversy and an improved geological water cycle model for the past 3.4
  billion years. Earth-Science Reviews 83, 83122 (2007). Kashefi, K. & Lovley, D. R. Extending the upper
  temperature limit for life. Science 301, 934 (2003). Kasting, J. F. Theoretical constraints on oxygen and
  carbon dioxide concentrations in the Precambrian atmosphere. Precambrian
  Research 34, 205229 (1987). Kasting, J. F. Earths early atmosphere. Science 259,
  920926 (1993). Kasting, J. F., Liu, S. C. & Donahue, T. M. Oxygen
  levels in the prebiological atmosphere. Journal of Geophysical Research 84,
  30973107 (1979). Kasting, J. F. et al. Paleoclimates, ocean depth, and the
  oxygen isotopic composition of seawater. Earth and Planetary Science Letters
  252, 8293 (2006). Kharecha, P., Kasting, J. & Seifert, J. A. A coupled
  atmosphere-ecosystem model of the early Archean Earth. Geobiology 3, 5376
  (2005). Knauth, L. P. & Lowe, D. R. High Archean climatic
  temperatures inferred from oxygen isotope geochemistry of cherts in the 3.5
  Ga Swaziland Supergroup, South Africa. Geological Society of America Bulletin
  155, 566580 (2003). Knoll, A. H. The early evolution of eukaryotic organisms:
  A geological perspective. Science 256, 922627 (1992). Knoll, A. H. et al. Eukaryotic organisms in Proterozoic
  oceans. Philosophical Transactions of the Royal Society B: Biological
  Sciences 361, 10231038 (2006). Kopp, R. E. et al. The Paleoproterozoic snowball Earth:
  A climatic disaster triggered by the evolution of oxygenic photosynthesis.
  Proceedings of the National Academy of Sciences of the United States of
  America 102, 1113111136 (2005). Kreidenweis, S. M. & Seinfeld, J. H. Nucleation of
  sulfuric acid-water and methanesulfonic acid-water solution particles:
  Implications for the atmospheric chemistry of organosulfur species.
  Atmosphere Environment 22, 283296 (1988). Lin, L-H. et al. Long-term sustainability of a
  high-energy, low-diversity crustal biome. Science 314, 479482 (2006). Locklair, R. E. & Lerman, A. A model of Phanerozoic
  cycles of carbon and calcium in the global ocean: Evaluation and constraints
  on ocean chemistry and input fluxes. Chemical Geology 217, 113126 (2005). Lowe, D. R. Restricted shallow water sedimentation of
  Early Archean stromatolitic and evaporitic strata of the Strelley Pool Chert,
  Pilbara Block, Western Australia. Precambrian Research 19, 239283 (1983). Lowe, D. R. & Tice, M. M. Geologic evidence for
  Archean atmosphere and climatic evolution: Fluctuating levels of CO2, CH4,
  and O2 with an overriding tectonic control. Geology 32, 493496 (2004). Mather, T. A., Pyle, D. M. & Allen, A. G. Volcanic
  source for fixed nitrogen in the early Earths atmosphere. Geology 32, 905908
  (2004). Maas, R. et al. The Earths oldest known crust: A
  geochronological and geochemical study of 39004200 Ma detrital zircons from
  Mt. Narryer and Jack Hills, Western Australia. Geochimica et Cosmochimica
  Acta 56, 12811300 (1992). Marmo, J. S. & Ojakangas, R. W. Lower Proterozoic
  glaciogenic deposits, eastern Finland. Geological Society of America Bulletin
  98, 10551062 (1984). Melezhik, V. A. Multiple causes of Earths earliest
  global glaciations. Terra Nova 18, 130137 (2006). Mojzsis, S. J., Harrison, T. M. & Pidgeon, R. T.
  Oxygen-isotope evidence from ancient zircons for liquid water at the Earths
  surface 4,300 Myr ago. Nature 409, 178181 (2001). Narbonne, G. M. & Gehling, J. G. Life after snowball:
  The oldest complex Ediacaran fossils. Geology 31, 2730 (2003). Noffke, N. et al. A new window into Early Archean life:
  Microbial mats in Earths oldest siliciclastic tidal deposits (3.2 Ga Moodies
  Group, South Africa). Geology 34, 253256 (2006). Pavlov, A. A. & Kasting, J. F. Mass-independent
  fractionation of sulfur isotopes in Archean sediments: Strong evidence for an
  anoxic Archean atmosphere. Astrobiology 2, 2741 (2002). Pavlov, A. A. et al. Greenhouse warming by CH4 in the
  atmosphere of early Earth. Journal of Geophysical Research 105, 1198111990
  (2000). Pavlov, A. A. et al. Methane-rich Proterozoic
  atmosphere? Geology 31, 8790 (2003). Peck, W. H. et al. Oxygen isotope ratios and rare earth
  elements in 3.3 to 4.4 Ga zircons: Ion microprobe evidence for high delta
  O-18 continental crust and oceans in the Early Archean. Geochimica et
  Cosmochimica Acta 65, 42154229 (2001). Rashby, S. E. et al. Biosynthesis of
  2-methylbacteriohopanepolyols by an anoxygenic phototroph. Proceedings of the
  National Academy of Sciences of the United States of America 104, 1509915014
  (2007). Rasmussen, B. & Buick, R. Redox state of the Archean
  atmosphere: Evidence from detrital heavy minerals in ca. 32502750 Ma
  sandstones from the Pilbara Craton, Australia. Geology 27, 115118 (1999). Rasmussen, B. et al. Reassessing the first appearance of
  eukaryotes and cyanobacteria. Nature 455, 11011105 (2008). Rondanelli, R. & Lindzen, R. S. Can thin cirrus
  clouds in the tropics provide a solution to the faint young Sun paradox?
  Journal of Geophysical Research 115, 689690 (2010). Rosing, M. T. 13C-depleted carbon microparticles in
  >3700-Ma sea-floor sedimentary rocks from west Greenland. Science 283,
  674676 (1999). Rosing, M. T. et al. No climate paradox under the faint
  Sun. Nature 464, 744747 (2010). Rossow, W. B., Henderson-Sellers, A. & Weinreich, S.
  K. Cloud feedback: A stabilizing effect for the early Earth? Science 217,
  12471247 (1982). Sagan, C. & Mullen, G. Earth and Mars  Evolution of
  atmospheres and surface temperatures. Science 177, 5256 (1972). Sheldon, N. D. Precambrian paleosols and atmospheric CO2
  levels. Precambrian Research 147, 148155 (2006). Sleep, N. H. & Hessler, A. M. Weathering of quartz
  as an Archean climatic indicator. Earth and Planetary Science Letters 241,
  594602 (2006). Summons, R. E. et al. 2-methyl-hopanoids as biomarkers
  for cyanobacterial oxygenic photosynthesis. Nature 400, 554557 (1999). Tice, M. M. & Lowe, D. R. Hydrogen-based carbon
  fixation in the earliest known photosynthetic organisms. Geology 34, 3740
  (2006). Trainer, M. G. et al. Organic haze on Titan and the
  early Earth. Proceedings of the National Academy of Sciences of the United
  States of America 103, 1803518042 (2006). Valley, J. W. et al. A cool early Earth. Geology 30, 351354
  (2002). Wilde, S. A. et al. Evidence from detrital zircons for
  the existence of continental crust and oceans on the Earth 4.4 Gyr ago.
  Nature 409, 175178 (2001). Zachos, J. et al. Trends, rhythms, and aberrations in
  global climate 65 Ma to present. Science 292, 686693 (2001). Zahnle, K. J.
  Photochemistry of methane and formation of hydrocyanic acid (HCN) in the
  Earths early atmosphere. Journal of Geophysical Research 91, 28192834
  (1986).   |