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24-591: The Piacenzian is roughly coeval with the European land mammal age MN 16, overlaps the late Chapadmalalan and early Uquian South American land mammal age and falls inside the more extensive Blancan North American land mammal age . It also correlates with the Astian, Redonian, Reuverian and Romanian regional stages of Europe, and the Waipipian and Mangapanian stages of New Zealand . Some authorities describe

48-638: A cause for Dansgaard–Oeschger cycles. A five year study lead by the Oxford School of Archaeology and additionally conducted by Royal Holloway , University of London , the Oxford University Museum of Natural History , and the National Oceanography Centre Southampton completed in 2013 called "Response of Humans to Abrupt Environmental Transitions" and referred to as "RESET" aimed to see if

72-496: A different mode on a time scale that is faster than the responsible forcing. In terms of impacts, an abrupt change is one that takes place so rapidly and unexpectedly that human or natural systems have difficulty adapting to it. These definitions are complementary: the former gives some insight into how abrupt climate change comes about; the latter explains why there is so much research devoted to it." Timescales of events described as abrupt may vary dramatically. Changes recorded in

96-480: A few decades and several thousand years. Finally, Earth System's models project that under ongoing greenhouse gas emissions as early as 2047, the Earth's near surface temperature could depart from the range of variability in the last 150 years. Several periods of abrupt climate change have been identified in the paleoclimatic record. Notable examples include: There are also abrupt climate changes associated with

120-408: A few decades and several thousand years. In comparison, climate models predict that under ongoing greenhouse gas emissions , the Earth's near surface temperature could depart from the usual range of variability in the last 150 years as early as 2047. Abrupt climate change can be defined in terms of physics or in terms of impacts: "In terms of physics, it is a transition of the climate system into

144-499: A flood cutting a new river channel. The best-known examples are the several dozen shutdowns of the North Atlantic Ocean 's Meridional Overturning Circulation during the last ice age , affecting climate worldwide. It has been postulated that teleconnections – oceanic and atmospheric processes on different timescales – connect both hemispheres during abrupt climate change. One source of abrupt climate change effects

168-572: A site called Ledi-Geraru between the Mille and Awash rivers, in Afar Regional State (near 11°22′N 40°52′E  /  11.36°N 40.86°E  / 11.36; 40.86 ). Based on geological evidence from the Afar region, the individual would have lived just after a major climate shift , during which forests and waterways were rapidly replaced by arid savanna . Regarding

192-414: Is a feedback process, in which a warming event causes a change that adds to further warming. The same can apply to cooling. Examples of such feedback processes are: The probability of abrupt change for some climate related feedbacks may be low. Factors that may increase the probability of abrupt climate change include higher magnitudes of global warming, warming that occurs more rapidly and warming that

216-801: Is named after the Italian city of Piacenza . The base of the Piacenzian is at the base of the Gauss chronozone and at the extinction of the planktonic forams Globorotalia margaritae and Pulleniatina primalis . The GSSP for the Piacenzian Stage is at Punta Piccola on Sicily , Italy. The top of the Piacenzian (the base of the Quaternary System and the Pleistocene Series) is defined magnetostratigraphically as

240-569: Is sustained over longer time periods. Possible tipping elements in the climate system include regional effects of climate change , some of which had abrupt onset and may therefore be regarded as abrupt climate change. Scientists have stated, "Our synthesis of present knowledge suggests that a variety of tipping elements could reach their critical point within this century under anthropogenic climate change". Isostatic rebound in response to glacier retreat (unloading) and increased local salinity have been attributed to increased volcanic activity at

264-572: The external forcing , though it may include sudden forcing events such as meteorite impacts . Abrupt climate change therefore is a variation beyond the variability of a climate . Past events include the end of the Carboniferous Rainforest Collapse , Younger Dryas , Dansgaard–Oeschger events , Heinrich events and possibly also the Paleocene–Eocene Thermal Maximum . The term is also used within

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288-402: The Afar region, and as stated in the journal Science : "Vertebrate fossils record a faunal turnover indicative of more open and probable arid habitats than those reconstructed earlier in this region, in broad agreement with hypotheses addressing the role of environmental forcing in hominin evolution at this time." This interpretation is consistent with hypotheses that emphasize the savanna as

312-568: The British Red Crag Formation and Waltonian Stage as late Piacenzian, while others regard them as early Pleistocene. Carbon dioxide levels during the Piacenzian were similar to those of today, making this age, with global mean temperature 2–3 °C higher and sea levels about twenty meters higher than today, an important analogue for predictions of the future of our world. The Piacenzian was introduced in scientific literature by Swiss stratigrapher Karl Mayer-Eymar in 1858. It

336-632: The Zanclean. Deposition of sediments and mollusks of the Piacenzian correspond with the rise in sea level creating the Tamiami Subsea and Jackson Subsea of Florida, Duplin Subsea generally of South Carolina , and Yorktown Subsea of the Outer Banks and inland North Carolina . Dates have been established on the basis of the genera and species of mollusks found. The late Piacenzian may be when

360-473: The ancestral environment which shaped the evolution of early Homo and other hominins. Coeval Read the Wiktionary entry "coeval" You can also: Abrupt climate change An abrupt climate change occurs when the climate system is forced to transition at a rate that is determined by the climate system energy-balance . The transition rate is more rapid than the rate of change of

384-718: The base of the Matuyama (C2r) chronozone (at the Gauss-Matuyama reversal ), and isotopic stage 103. Above this point there are notable extinctions of the calcareous nannofossils : Discoaster pentaradiatus and Discoaster surculus . The Piacenzian was the last age before the Quaternary glaciations started to take hold in the Northern hemisphere. The ice sheet of Antarctica was also less prominent than today and sea levels were approximately twenty meters higher than

408-609: The carbon dioxide concentration stabilizes at this level. In particular, the KM5c interglacial during the Mid-Piacenzian Warm Period occurred during an orbital configuration close to the current situation, with similar geographical distribution of solar insolation . Climate of the Piacenzian would have started as a somewhat wet and warm period in North America occurring just after a brief cooling period of

432-651: The catastrophic draining of glacial lakes. One example of this is the 8.2-kiloyear event , which is associated with the draining of Glacial Lake Agassiz . Another example is the Antarctic Cold Reversal , c. 14,500 years before present ( BP ), which is believed to have been caused by a meltwater pulse probably from either the Antarctic ice sheet or the Laurentide Ice Sheet . These rapid meltwater release events have been hypothesized as

456-564: The climate of Greenland at the end of the Younger Dryas, as measured by ice-cores, imply a sudden warming of +10 °C (+18 °F) within a timescale of a few years. Other abrupt changes are the +4 °C (+7.2 °F) on Greenland 11,270 years ago or the abrupt +6 °C (11 °F) warming 22,000 years ago on Antarctica . By contrast, the Paleocene–Eocene Thermal Maximum may have initiated anywhere between

480-448: The context of climate change to describe sudden climate change that is detectable over the time-scale of a human lifetime. Such a sudden climate change can be the result of feedback loops within the climate system or tipping points in the climate system . Scientists may use different timescales when speaking of abrupt events . For example, the duration of the onset of the Paleocene–Eocene Thermal Maximum may have been anywhere between

504-488: The genus Homo developed out of the ancestral genus Australopithecus . While the oldest known fossils unambiguously identified as Homo habilis date to just after the end of the Piacenzian (2.58 Ma), a fossilized jawbone that exhibits traits that are transitional between Australopithecus and Homo habilis was discovered in the Afar Triangle in 2015. The find was made by Ethiopian student Chalachew Seyoum at

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528-400: The hypothesis that humans have major development shifts during or immediately after abrupt climate changes with the aid of knowledge pulled from research on the palaeoenvironmental conditions, prehistoric archaeological history, oceanography, and volcanic geology of the last 130,000 years and across continents. It also aimed to predict possible human behavior in the event of climate change, and

552-483: The present. The global mean temperature was 2–3 °C warmer than the pre-industrial temperature. During the Mid-Piacenzian Warm Period the concentration of carbon dioxide peaked at approximately 389 ppm (in the range 381–427 ppm with 95% confidence), thus similar to the concentration during the 2010s. The Piacenzian can therefore be used as an analogue to the future climate and sea level to expect if

576-591: The timing of climate change. A 2017 study concluded that similar conditions to today's Antarctic ozone hole (atmospheric circulation and hydroclimate changes), ~17,700 years ago, when stratospheric ozone depletion contributed to abrupt accelerated Southern Hemisphere deglaciation . The event coincidentally happened with an estimated 192-year series of massive volcanic eruptions, attributed to Mount Takahe in West Antarctica . Most abrupt climate shifts are likely due to sudden circulation shifts, analogous to

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