Medieval Warm Period

{{short description|Period of warm climate in North Atlantic region lasting from about 950 CE to about 1250}}

File:2000+ year global temperature including Medieval Warm Period and Little Ice Age - Ed Hawkins.svg

The Medieval Warm Period (MWP), also known as the Medieval Climate Optimum or the Medieval Climatic Anomaly, was a time of warm climate in the North Atlantic region that lasted from about {{CE|950|link=yes}} to about {{CE|1250}}. Climate proxy records show peak warmth occurred at different times for different regions, which indicate that the MWP was not a globally uniform event.{{cite book |author=Solomon, Susan Snell; Intergovernmental Panel on Climate Change |url=http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html |title=Climate change 2007: the physical science basis: contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change |publisher=Cambridge University Press for the Intergovernmental Panel on Climate Change |year=2007 |isbn=978-0-521-70596-7 |location=Cambridge |chapter=6.6 The Last 2,000 Years |chapter-url=http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch6s6-6.html }} [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch6s6-6.html Box 6.4] {{Webarchive|url=https://web.archive.org/web/20150328093747/http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch6s6-6.html |date=2015-03-28 }} Some refer to the MWP as the Medieval Climatic Anomaly to emphasize that climatic effects other than temperature were also important.

The MWP was followed by a regionally cooler period in the North Atlantic and elsewhere, which is sometimes called the Little Ice Age (LIA).

Possible causes of the MWP include increased solar activity, decreased volcanic activity, and changes in ocean circulation.{{cite web |title=How does the Medieval Warm Period compare to current global temperatures? |url=http://www.skepticalscience.com/medieval-warm-period.htm |access-date=October 12, 2017 |work=SkepticalScience}} Modelling evidence has shown that natural variability is insufficient on its own to explain the MWP and that an external forcing had to be one of the causes.{{Cite journal |last=Hunt |first=B. G. |date=11 May 2006 |title=The Medieval Warm Period, the Little Ice Age and simulated climatic variability |url=http://link.springer.com/10.1007/s00382-006-0153-5 |journal=Climate Dynamics |language=en |volume=27 |issue=7–8 |pages=677–694 |doi=10.1007/s00382-006-0153-5 |bibcode=2006ClDy...27..677H |s2cid=128890550 |issn=0930-7575 |access-date=5 September 2023|url-access=subscription }}

Research

The MWP is generally thought to have occurred from about {{CE|950}} to about {{CE|1250}}, during the European Middle Ages. Some researchers divide the MWP into two phases: MWP-I, which began around {{CE|450}} and ended around {{CE|900}}, and MWP-II, which lasted from about {{CE|1000}} to about {{CE|1300}}; MWP-I is called the early Medieval Warm Period while MWP-II is called the conventional Medieval Warm Period.{{Cite journal |last1=Cronin |first1=T.M |last2=Dwyer |first2=G.S |last3=Kamiya |first3=T |last4=Schwede |first4=S |last5=Willard |first5=D.A |date=March 2003 |title=Medieval Warm Period, Little Ice Age and 20th century temperature variability from Chesapeake Bay |url=https://linkinghub.elsevier.com/retrieve/pii/S0921818102001613 |journal=Global and Planetary Change |language=en |volume=36 |issue=1–2 |pages=17–29 |doi=10.1016/S0921-8181(02)00161-3 |bibcode=2003GPC....36...17C |access-date=5 September 2023|hdl=10161/6578 |hdl-access=free }} In 1965, Hubert Lamb, one of the first paleoclimatologists, published research based on data from botany, historical document research, and meteorology, combined with records indicating prevailing temperature and rainfall in England around {{CE|1200}} and around {{CE|1600}}. He proposed,{{cite journal |doi=10.1016/0031-0182(65)90004-0 |title=The early medieval warm epoch and its sequel |year=1965 |last1=Lamb |first1=H.H. |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=1 |pages=13–37|bibcode=1965PPP.....1...13L }}

{{blockquote |text=evidence has been accumulating in many fields of investigation pointing to a notably warm climate in many parts of the world, that lasted a few centuries around {{CE|1000–1200}}, and was followed by a decline of temperature levels till between around {{CE|1500–1700}} the coldest phase since the last ice age occurred.}}

The era of warmer temperatures became known as the Medieval Warm Period and the subsequent cold period the Little Ice Age (LIA). However, the view that the MWP was a global event was challenged by other researchers. The IPCC First Assessment Report of 1990 discussed the:

{{blockquote |text=Medieval Warm Period around {{CE|1000}} (which may not have been global) and the Little Ice Age which ended only in the middle to late nineteenth century.}}

It stated that temperatures in the:IPCC First Assessment Report Working Group 1 report, [https://www.ipcc.ch/site/assets/uploads/2018/03/ipcc_far_wg_I_chapter_07-1.pdf Chapter 7], Executive Summary p. 199, Climate of the Past 5,000,000 Years p. 202.

{{blockquote |text=late tenth to early thirteenth centuries (about {{CE|950–1250}}) appear to have been exceptionally warm in western Europe, Iceland and Greenland.}}

The IPCC Third Assessment Report from 2001 summarized newer research:

{{blockquote |text=evidence does not support globally synchronous periods of anomalous cold or warmth over this time frame, and the conventional terms of 'Little Ice Age' and 'Medieval Warm Period' are chiefly documented in describing northern hemisphere trends in hemispheric or global mean temperature changes in past centuries.}}

Global temperature records taken from ice cores, tree rings, and lake deposits have shown that the Earth may have been slightly cooler globally (by {{convert|0.03|C-change|1|disp=or}}) than in the early and the mid-20th century.

Palaeoclimatologists developing region-specific climate reconstructions of past centuries conventionally label their coldest interval as "LIA" and their warmest interval as the "MWP". Others follow the convention, and when a significant climate event is found in the "LIA" or "MWP" timeframes, they associate their events to the period. Some "MWP" events are thus wet events or cold events, rather than strictly warm events, particularly in central Antarctica, where climate patterns that are opposite to those of the North Atlantic have been noticed.

Using methods of historical climatology, Christian Pfister and Heinz Wanner reconstructed the seasonal temperature conditions for Western and Central Europe in 2021 on the basis of indices from CE 1000 to 1999 (the autumns only from 1500 onwards).{{Cite journal |last1=Wanner |first1=Heinz |last2=Pfister |first2=Christian |last3=Neukom |first3=Raphael |date=2022-07-01 |title=The variable European Little Ice Age |url=https://linkinghub.elsevier.com/retrieve/pii/S0277379122001627 |journal=Quaternary Science Reviews |volume=287 |pages=107531 |doi=10.1016/j.quascirev.2022.107531 |bibcode=2022QSRv..28707531W |issn=0277-3791|url-access=subscription }}{{Cite book |last1=Pfister |first1=Christian |title=Klima und Gesellschaft in Europa: die letzten tausend Jahre |last2=Wanner |first2=Heinz |date=2021 |publisher=Haupt Verlag |isbn=978-3-258-08182-3 |edition= |location=Bern}}

Global climate during the Medieval Warm Period

The nature and extent of the MWP has been marked by long-standing controversy over whether it was a global or regional event.{{cite journal |last1=Broecker |first1=Wallace S. |date=23 February 2001 |title=Was the Medieval Warm Period Global? |url=https://www.science.org/doi/full/10.1126/science.291.5508.1497 |journal=Science |volume=291 |issue=5508 |pages=1497–1499 |doi=10.1126/science.291.5508.1497 |pmid=11234078 |s2cid=17674208 |access-date=18 June 2023|url-access=subscription }}{{cite journal |last1=Hughes |first1=Malcolm K. |last2=Diaz |first2=Henry F. |date=March 1994 |title=Was there a 'medieval warm period', and if so, where and when? |url=https://link.springer.com/article/10.1007/BF01092410 |journal=Climatic Change |volume=26 |issue=2–3 |pages=109–142 |bibcode=1994ClCh...26..109H |s2cid=128680153 |doi=10.1007/BF01092410 |access-date=18 June 2023|url-access=subscription }} In 2019, by using an extended proxy data set,{{Cite journal |last1=Emile-Geay |first1=Julien |last2=McKay |first2=Nicholas P.|last3=Kaufman |first3=Darrell S. |last4=von Gunten |first4=Lucien |last5=Wang |first5=Jianghao |last6=Anchukaitis |first6=Kevin J. |last7=Abram |first7=Nerilie J. |last8=Addison |first8=Jason A. |last9=Curran |first9=Mark A.J. |last10=Evans |first10=Michael N. |last11=Henley |first11=Benjamin J. |date=2017-07-11 |title=A global multiproxy database for temperature reconstructions of the Common Era |journal=Scientific Data |language=en |volume=4 |issue=1 |pages=170088 |doi=10.1038/sdata.2017.88 |pmid=28696409 |pmc=5505119 |bibcode=2017NatSD...470088E |issn=2052-4463 |doi-access=free}} the Pages-2k consortium confirmed that the Medieval Climate Anomaly was not a globally synchronous event. The warmest 51-year period within the MWP did not occur at the same time in different regions. They argue for a regional instead of global framing of climate variability in the preindustrial Common Era to aid in understanding.{{Cite journal |last1=Neukom |first1=Raphael |last2=Steiger |first2=Nathan |last3=Gómez-Navarro |first3=Juan José |last4=Wang |first4=Jianghao |last5=Werner |first5=Johannes P. |date=2019 |title=No evidence for globally coherent warm and cold periods over the preindustrial Common Era |url=https://www.nature.com/articles/s41586-019-1401-2 |journal=Nature |language=en |volume=571 |issue=7766 |pages=550–554 |doi=10.1038/s41586-019-1401-2 |pmid=31341300 |bibcode=2019Natur.571..550N |s2cid=198494930 |issn=1476-4687|url-access=subscription }}

North Atlantic

File:Greenland ice sheet temperatures Vinther et al 2009.png

Lloyd D. Keigwin's 1996 study of radiocarbon-dated box core data from marine sediments in the Sargasso Sea found that its sea surface temperature was approximately {{convert|1|C-change|1}} cooler approximately 400 years ago, during the LIA, and 1700 years ago, and was approximately {{convert|1|C-change|1}} warmer 1000 years ago, during the MWP.

Using sediment samples from Puerto Rico, the Gulf Coast, and the Atlantic Coast from Florida to New England, Mann et al. found consistent evidence of a peak in North Atlantic tropical cyclone activity during the MWP, which was followed by a subsequent lull in activity.{{cite journal |doi=10.1038/nature08219 |title=Atlantic hurricanes and climate over the past 1,500 years |year=2009 |last1=Mann |first1=Michael E. |author1-link=Michael E. Mann |last2=Woodruff |first2=Jonathan D. |last3=Donnelly |first3=Jeffrey P. |last4=Zhang |first4=Zhihua |journal=Nature |volume=460 |issue=7257 |pages=880–3 |pmid=19675650 |bibcode = 2009Natur.460..880M |hdl=1912/3165 |s2cid=233167 |hdl-access=free}}

= Iceland =

Iceland was first settled between about 865 and 930, during a time believed to be warm enough for sailing and farming.{{Cite book |last=Gunnar Karlsson |url=https://www.worldcat.org/oclc/42736334 |title=The history of Iceland |date=2000 |publisher=University of Minnesota Press |isbn=0-8166-3588-9 |location=Minneapolis, Minn. |oclc=42736334}}{{Cite book |last=Lamb |first=H. H. |url=https://www.worldcat.org/oclc/900419132 |title=Climate : present, past and future. Volume 2, Climatic history and the future |date=2011 |publisher=Routledge |isbn=978-0-203-80430-8 |location=Abingdon, Oxon |oclc=900419132}} By retrieval and isotope analysis of marine cores and from examination of mollusc growth patterns from Iceland, Patterson et al. reconstructed a stable oxygen (δ¹⁸ O) and carbon (δ¹³ C) isotope record at a decadal resolution from the Roman Warm Period to the MWP and the LIA.{{cite journal |doi=10.1073/pnas.0902522107 |title=Two millennia of North Atlantic seasonality and implications for Norse colonies |year=2010 |last1=Patterson |first1=W. P. |last2=Dietrich |first2=K. A. |last3=Holmden |first3=C. |last4=Andrews |first4=J. T. |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=107 |issue=12 |pages=5306–10 |bibcode = 2010PNAS..107.5306P |pmid=20212157 |pmc=2851789|doi-access=free }} Patterson et al. conclude that the summer temperature stayed high but winter temperature decreased after the initial settlement of Iceland.

= Greenland =

File:Hvalsey Church.jpg are from an Icelandic marriage in 1408 but were recorded later in Iceland, at Hvalsey Church, which is now the best-preserved of the Norse ruins.]]

The Mann et al. study found warmth exceeding 1961–1990 levels in southern Greenland and parts of North America during the MWP, which the study defines as from 950 to 1250, with warmth in some regions exceeding temperatures of the 1990–2010 period. Much of the Northern Hemisphere showed a significant cooling during the LIA, which the study defines as from 1400 to 1700, but Labrador and isolated parts of the United States appeared to be approximately as warm as during the 1961–1990 period. Greenlandic winter oxygen isotope data from the MWP display a strong correlation with the North Atlantic Oscillation (NAO).{{cite journal |doi=10.1016/j.quascirev.2009.11.002 |title=Climatic signals in multiple highly resolved stable isotope records from Greenland |date=February 2010 |url=https://www.sciencedirect.com/science/article/abs/pii/S0277379109003655 |last1=Vinther |first1=B. M. |last2=Jones |first2=P. D. |last3=Briffa |first3=K. R. |last4=Clausen |first4=H. B. |last5=Andersen |first5=K. K. |last6=Dahl-Jensen |first6=D. |author-link6=Dorthe Dahl-Jensen |last7=Johnsen |first7=S. J. |journal=Quaternary Science Reviews |volume=29 |issue=3–4 |pages=522–538 |bibcode = 2010QSRv...29..522V |url-access=subscription }}File:Skálholt-Karte.png map, based on documentary information about earlier Norse sites in America.]]

The Norse colonization of the Americas has been associated with warmer periods.{{cite journal |last1=D'Andrea |first1=William J. |last2=Huang |first2=Yongsong |last3=Fritz |first3=Sherilyn C. |last4=Anderson |first4=N. John |date=31 May 2011 |title=Abrupt Holocene climate change as an important factor for human migration in West Greenland |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=108 |issue=24 |pages=9765–9769 |doi=10.1073/pnas.1101708108 |pmid=21628586 |pmc=3116382 |bibcode=2011PNAS..108.9765D |doi-access=free }} The common theory is that Norsemen took advantage of ice-free seas to colonize areas in Greenland and other outlying lands of the far north.{{cite book |last=Diamond |first=Jared |url=https://archive.org/details/collapse00jare |title=Collapse: How Societies Choose to Fail or Succeed |publisher=Penguin Books |year=2005 |isbn=0-670-03337-5 |location=New York |author-link=Jared Diamond|pages=216–220}} However, a study from Columbia University suggests that Greenland was not colonized in warmer weather, but the warming effect in fact lasted for only very briefly.{{cite web |title=Study Undercuts Idea That 'Medieval Warm Period' Was Global – The Earth Institute – Columbia University |url=http://www.earth.columbia.edu/articles/view/3266 |access-date=7 April 2018 |website=earth.columbia.edu}} Around {{CE|1000}} the climate was sufficiently warm for the Vikings to journey to Newfoundland and to establish a short-lived outpost there.{{Cite book |author=Ingstad, Anne Stine |url=https://archive.org/details/vikingdiscoveryo00ings/page/141 |title=The Viking Discovery of America |publisher=Checkmark |year=2001 |isbn=978-0-8160-4716-1 |editor1=Helge Ingstad |location=New York |pages=[https://archive.org/details/vikingdiscoveryo00ings/page/141 141–169] |chapter=The Excavation of a Norse Settlement at L'Anse aux Meadows, Newfoundland |oclc=46683692 |author-link=Anne Stine Ingstad |editor2=Anne Stine Ingstad |chapter-url=https://archive.org/details/vikingdiscoveryo00ings}}

File:Authentic Viking recreation.jpg, Newfoundland, today, with a reconstruction of a Viking settlement.]]Around 985, Vikings founded the Eastern and Western Settlements, both near the southern tip of Greenland. In the colony's early stages, they kept cattle, sheep, and goats, with around a quarter of their diet from seafood. After the climate became colder and stormier around 1250, their diet steadily shifted towards ocean sources. By around 1300, seal hunting provided over three quarters of their food.

By 1350, there was reduced demand for their exports, and trade with Europe fell away. The last document from the settlements dates from 1412, and over the following decades, the remaining Europeans left in what seems to have been a gradual withdrawal, which was caused mainly by economic factors such as increased availability of farms in Scandinavian countries.{{Cite web |last=Stockinger |first=Günther |date=10 January 2012 |title=Archaeologists Uncover Clues to Why Vikings Abandoned Greenland |url=http://www.spiegel.de/international/zeitgeist/archaeologists-uncover-clues-to-why-vikings-abandoned-greenland-a-876626.html |access-date=12 January 2013 |publisher=Der Spiegel Online}}

= Europe =

Substantial glacial retreat in southern Europe was experienced during the MWP. While several smaller glaciers experienced complete deglaciation, larger glaciers in the region survived and now provide insight into the region's climate history.{{Cite journal |last1=Moreno |first1=Ana |last2=Bartolomé |first2=Miguel |last3=López-Moreno |first3=Juan Ignacio |last4=Pey |first4=Jorge |last5=Corella |first5=Juan Pablo |last6=García-Orellana |first6=Jordi |last7=Sancho |first7=Carlos |last8=Leunda |first8=María |last9=Gil-Romera |first9=Graciela |last10=González-Sampériz |first10=Penélope |last11=Pérez-Mejías |first11=Carlos |date=3 March 2021 |title=The case of a southern European glacier which survived Roman and medieval warm periods but is disappearing under recent warming |url=https://tc.copernicus.org/articles/15/1157/2021/ |journal=The Cryosphere |language=English |volume=15 |issue=2 |pages=1157–1172 |doi=10.5194/tc-15-1157-2021 |bibcode=2021TCry...15.1157M |s2cid=232275176 |issn=1994-0416 |doi-access=free |hdl=10810/51794 |hdl-access=free }} In addition to warming induced glacial melt, sedimentary records reveal a period of increased flooding, coinciding with the MWP, in eastern Europe that is attributed to enhanced precipitation from a positive phase NAO.{{Cite journal |last1=Perșoiu |first1=Ioana |last2=Perșoiu |first2=Aurel |date=2019 |title=Flood events in Transylvania during the Medieval Warm Period and the Little Ice Age |journal=The Holocene |language=en |volume=29 |issue=1 |pages=85–96 |doi=10.1177/0959683618804632 |bibcode=2019Holoc..29...85P |s2cid=134035133 |issn=0959-6836|doi-access=free }} Other impacts of climate change can be less apparent such as a changing landscape. Preceding the MWP, a coastal region in western Sardinia was abandoned by the Romans. The coastal area was able to substantially expand into the lagoon without the influence of human populations and a high stand during the MWP. When human populations returned to the region, they encountered a land altered by climate change and had to reestablish ports.{{Cite journal |last1=Pascucci |first1=V. |last2=De Falco |first2=G. |last3=Del Vais |first3=C. |last4=Sanna |first4=I. |last5=Melis |first5=R. T. |last6=Andreucci |first6=S. |date=1 January 2018 |title=Climate changes and human impact on the Mistras coastal barrier system (W Sardinia, Italy) |url=https://www.sciencedirect.com/science/article/pii/S0025322717302372 |journal=Marine Geology |language=en |volume=395 |pages=271–284 |doi=10.1016/j.margeo.2017.11.002 |bibcode=2018MGeol.395..271P |issn=0025-3227|url-access=subscription }} In the Iberian Central Range, there was elevated lake productivity and soil erosion, along with frequent intense runoff events.{{Cite journal |last1=Sánchez-López |first1=G. |last2=Hernández |first2=A. |last3=Pla-Rabes |first3=S. |last4=Trigo |first4=R.M. |last5=Toro |first5=M. |last6=Granados |first6=I. |last7=Sáez |first7=A. |last8=Masqué |first8=P. |last9=Pueyo |first9=J.J. |last10=Rubio-Inglés |first10=M.J. |last11=Giralt |first11=S. |date=October 2016 |title=Climate reconstruction for the last two millennia in central Iberia: The role of East Atlantic (EA), North Atlantic Oscillation (NAO) and their interplay over the Iberian Peninsula |url=https://linkinghub.elsevier.com/retrieve/pii/S0277379116302566 |journal=Quaternary Science Reviews |language=en |volume=149 |pages=135–150 |doi=10.1016/j.quascirev.2016.07.021 |bibcode=2016QSRv..149..135S |access-date=13 April 2024 |via=Elsevier Science Direct|hdl=2445/101594 |hdl-access=free }}

Other regions

= North America =

In Chesapeake Bay (now in Maryland and Virginia, United States), researchers found large temperature excursions (changes from the mean temperature of that time) during the MWP (about 950–1250) and the Little Ice Age (about 1400–1700, with cold periods persisting into the early 20th century), which are possibly related to changes in the strength of North Atlantic thermohaline circulation.{{cite web| url=http://geology.er.usgs.gov/eespteam/Atlantic/GPCabs.htm| title=Medieval Warm Period, Little Ice Age and 20th Century Temperature Variability from Chesapeake Bay| publisher=USGS| access-date=2006-05-04| url-status=dead| archive-url=https://web.archive.org/web/20060630212731/http://geology.er.usgs.gov/eespteam/Atlantic/GPCabs.htm| archive-date=2006-06-30}} Sediments in Piermont Marsh of the lower Hudson Valley show a dry MWP from 800 to 1300.{{cite web|url=http://eobglossary.gsfc.nasa.gov/Newsroom/NasaNews/2005/2005051918986.html |date=May 19, 2005 |publisher=Earth Observatory News |title=Marshes Tell Story Of Medieval Drought, Little Ice Age, And European Settlers Near New York City |access-date=2006-05-04 |url-status=dead |archive-url=https://web.archive.org/web/20061002151119/http://eobglossary.gsfc.nasa.gov/Newsroom/NasaNews/2005/2005051918986.html |archive-date=October 2, 2006 }} In the Hammock River marsh in Connecticut, salt marshes extended {{convert|15|km}} farther westward than they do in the present due to higher sea levels.{{cite journal |last1=Van de Plassche |first1=Orson |last2=Van der Borg |first2=Klaas |last3=De Jong |first3=Arie F. M. |date=1 April 1998 |title=Sea level–climate correlation during the past 1400 yr |url=https://pubs.geoscienceworld.org/gsa/geology/article-abstract/26/4/319/206863/Sea-level-climate-correlation-during-the-past-1400 |journal=Geology |volume=26 |issue=4 |pages=319–322 |doi=10.1130/0091-7613(1998)026<0319:SLCCDT>2.3.CO;2 |bibcode=1998Geo....26..319V |access-date=14 July 2023|url-access=subscription }}

Prolonged droughts affected many parts of what is now the Western United States, especially eastern California and the west of Great Basin. Alaska experienced three intervals of comparable warmth: 1–300, 850–1200, and since 1800.{{cite journal |doi=10.1073/pnas.181333798 |title=Pronounced climatic variations in Alaska during the last two millennia |year=2001 |last1=Hu |first1=F. S. |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=98 |issue=19 |pages=10552–10556|bibcode = 2001PNAS...9810552H |pmid=11517320 |pmc=58503|doi-access=free }} Knowledge of the MWP in North America has been useful in dating occupancy periods of certain Native American habitation sites, especially in arid parts of the Western United States.{{cite journal |doi=10.1007/BF01092416 |title=The medieval warm period on the southern Colorado Plateau |year=1994 |last1=Dean |first1=Jeffrey S. |journal=Climatic Change |volume=26 |issue=2–3 |pages=225–241|bibcode=1994ClCh...26..225D |s2cid=189877071 }}C. Michael Hogan (2008) [http://www.megalithic.co.uk/article.php?sid=18353 Los Osos Back Bay], Megalithic Portal, editor A. Burnham. Aridity was more prevalent in the southeastern United States during the MWP than the following LIA, but only slightly; this difference may be statistically insignificant.{{Cite journal |last1=Stahle |first1=David W. |last2=Cleaveland |first2=Malcolm K. |date=March 1994 |title=Tree-ring reconstructed rainfall over the southeastern U.S.A. during the medieval warm period and little ice age |url=http://link.springer.com/10.1007/BF01092414 |journal=Climatic Change |language=en |volume=26 |issue=2–3 |pages=199–212 |doi=10.1007/BF01092414 |bibcode=1994ClCh...26..199S |s2cid=189878139 |issn=0165-0009 |access-date=5 September 2023|url-access=subscription }} Droughts in the MWP may have impacted Native American settlements also in the Eastern United States, such as at Cahokia.{{Cite journal |last1=Benson |first1=Larry V. |last2=Pauketat |first2=Timothy R. |last3=Cook |first3=Edward R. |date=2009 |title=Cahokia's Boom and Bust in the Context of Climate Change |url=https://www.cambridge.org/core/journals/american-antiquity/article/cahokias-boom-and-bust-in-the-context-of-climate-change/450C4880F8F28C35181AFBF94A075B38 |journal=American Antiquity |language=en |volume=74 |issue=3 |pages=467–483 |doi=10.1017/S000273160004871X |s2cid=160679096 |issn=0002-7316|url-access=subscription }}{{Cite journal |last1=White |first1=A. J. |last2=Stevens |first2=Lora R. |last3=Lorenzi |first3=Varenka |last4=Munoz |first4=Samuel E. |last5=Schroeder |first5=Sissel |last6=Cao |first6=Angelica |last7=Bogdanovich |first7=Taylor |date=19 March 2019 |title=Fecal stanols show simultaneous flooding and seasonal precipitation change correlate with Cahokia's population decline |journal=Proceedings of the National Academy of Sciences of the United States of America |language=en |volume=116 |issue=12 |pages=5461–5466 |doi=10.1073/pnas.1809400116|issn=0027-8424 |pmc=6431169 |pmid=30804191 |bibcode=2019PNAS..116.5461W |doi-access=free}} Review of more recent archaeological research shows that as the search for signs of unusual cultural changes has broadened, some of the early patterns (such as violence and health problems) have been found to be more complicated and regionally varied than had been previously thought. Other patterns, such as settlement disruption, deterioration of long-distance trade, and population movements, have been further corroborated.{{cite journal |doi=10.1016/j.quaint.2007.07.007 |title=Archaeological perspectives on the effects of medieval drought in prehistoric California |year=2008 |last1=Jones |first1=Terry L. |last2=Schwitalla |first2=Al |journal=Quaternary International |volume=188 |issue=1 |pages=41–58|bibcode = 2008QuInt.188...41J|url=https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1014&context=ssci_fac |url-access=subscription }}

= Africa =

The climate in equatorial eastern Africa has alternated between being drier than today and relatively wet. The climate was drier during the MWP (1000–1270).{{cite web|url=http://earthobservatory.nasa.gov/Newsroom/MediaAlerts/2004/2004100717709.html |date=2004-10-07

|title=Drought In West Linked To Warmer Temperatures |publisher=Earth Observatory News |access-date=2006-05-04 |url-status=dead

|archive-url=https://web.archive.org/web/20061004115822/http://earthobservatory.nasa.gov/Newsroom/MediaAlerts/2004/2004100717709.html |archive-date=2006-10-04}} Off the coast of Africa, Isotopic analysis of bones from the Canary Islands' inhabitants during the MWP to LIA transition reveal the region experienced a {{convert|5|C-change|1|adj=on}} decrease in air temperature. Over this period, the diet of inhabitants did not appreciably change, which suggests they were remarkably resilient to climate change.{{Cite journal |last1=Lécuyer |first1=Christophe |last2=Goedert |first2=Jean |last3=Klee |first3=Johanne |last4=Clauzel |first4=Thibault |last5=Richardin |first5=Pascale |last6=Fourel |first6=François |last7=Delgado-Darias |first7=Teresa |last8=Alberto-Barroso |first8=Verónica |last9=Velasco-Vázquez |first9=Javier |last10=Betancort |first10=Juan Francisco |last11=Amiot |first11=Romain |date=2021-04-01 |title=Climatic change and diet of the pre-Hispanic population of Gran Canaria (Canary Archipelago, Spain) during the Medieval Warm Period and Little Ice Age |url=https://www.researchgate.net/publication/349279673 |journal=Journal of Archaeological Science |language=en |volume=128 |pages=105336 |doi=10.1016/j.jas.2021.105336 |bibcode=2021JArSc.128j5336L |s2cid=233597524 |issn=0305-4403 |doi-access=free |access-date=18 June 2023}}

= Antarctica =

The onset of the MWP in the Southern Ocean lagged the MWP's onset in the North Atlantic by approximately 150 years.{{cite journal |last1=Goosse |first1=H. |last2=Masson-Delmotte |first2=V. |last3=Renssen |first3=H. |last4=Delmotte |first4=M. |last5=Fichefet |first5=T. |last6=Morgan |first6=V. |last7=Van Ommen |first7=T. |last8=Khim |first8=B. K. |last9=Stenni |first9=B. |date=17 March 2004 |title=A late medieval warm period in the Southern Ocean as a delayed response to external forcing? |journal=Geophysical Research Letters |volume=31 |issue=6 |pages=1–5 |doi=10.1029/2003GL019140 |bibcode=2004GeoRL..31.6203G |s2cid=17322719 |doi-access=free }} A sediment core from the eastern Bransfield Basin, in the Antarctic Peninsula, preserves climatic events from both the LIA and the MWP. The authors noted, "The late Holocene records clearly identify Neoglacial events of the LIA and Medieval Warm Period (MWP)."{{cite journal |bibcode=2002QuRes..58..234K |title=Unstable Climate Oscillations during the Late Holocene in the Eastern Bransfield Basin, Antarctic Peninsula |last1=Khim |first1=B. |volume=58 |year=2002 |pages=234 |journal=Quaternary Research |doi=10.1006/qres.2002.2371 |last2=Yoon |first2=Ho Il |last3=Kang |first3=Cheon Yun |last4=Bahk |first4=Jang Jun |issue=3|s2cid=129384061}} Some Antarctic regions were atypically cold, but others were atypically warm between 1000 and 1200.{{Cite journal |last1=Lüning |first1=Sebastian |last2=Gałka |first2=Mariusz |last3=Vahrenholt |first3=Fritz |date=15 October 2019 |title=The Medieval Climate Anomaly in Antarctica |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=532 |pages=109251 |doi=10.1016/j.palaeo.2019.109251 |bibcode=2019PPP...53209251L |issn=0031-0182 |doi-access=free}}

= Pacific Ocean =

Corals in the tropical Pacific Ocean suggest that relatively cool and dry conditions may have persisted early in the millennium, which is consistent with a La Niña-like configuration of the El Niño-Southern Oscillation patterns.{{cite web| url=http://www.pac.ne.jp/IUGG2003/EN/program.asp?session_id=MC12&program_id=022025-1| publisher=The Climate of the Holocene (ICCI) 2003| date=July 8, 2003| title=The Medieval Cool Period And The Little Warm Age In The Central Tropical Pacific? Fossil Coral Climate Records Of The Last Millennium| first=Kim M.| last=Cobb|author2=Chris Charles |author3=Hai Cheng |author4=R. Lawrence Edwards | access-date=4 May 2006 |archive-url = https://web.archive.org/web/20040825145637/http://www.pac.ne.jp/IUGG2003/EN/program.asp?session_id=MC12&program_id=022025-1 |archive-date = August 25, 2004}}

In 2013, a study from three US universities was published in Science magazine and showed that the water temperature in the Pacific Ocean was {{convert|0.9|C-change|1}} warmer during the MWP than during the LIA and {{convert|0.65|C-change|1}} warmer than the decades before the study.{{Cite journal |last1=Rosenthal |first1=Yair |last2=Linsley |first2=Braddock K. |last3=Oppo |first3=Delia W. |date=2013-11-01 |title=Pacific Ocean Heat Content During the Past 10,000 Years |url=https://www.science.org/doi/10.1126/science.1240837 |journal=Science |language=en |volume=342 |issue=6158 |pages=617–621 |doi=10.1126/science.1240837 |issn=0036-8075 |pmid=24179224 |bibcode=2013Sci...342..617R |s2cid=140727975|url-access=subscription }}

= South America =

The MWP has been noted in Chile in a 1500-year lake bed sediment core,{{cite journal |title=Vegetation, climate and fire regime changes in the Andean region of southern Chile (38°S) covaried with centennial-scale climate anomalies in the tropical Pacific over the last 1500 years |last1=Fletcher |first1=M-S. |last2=Moreno |first2=P.I. |journal=Quaternary Science Reviews |volume=46 |pages=46–56 |date=16 July 2012 |doi=10.1016/j.quascirev.2012.04.016 |bibcode = 2012QSRv...46...46F|hdl=10533/131338 |hdl-access=free }} as well as in the Eastern Cordillera of Ecuador.{{cite journal | last1 = Ledru | first1 = M.-P. | last2 = Jomelli | first2 = V. | last3 = Samaniego | first3 = P. | last4 = Vuille | first4 = M. | last5 = Hidalgo | first5 = S. | last6 = Herrera | first6 = M. | last7 = Ceron | first7 = C. | year = 2013 | title = The Medieval Climate Anomaly and the Little Ice Age in the eastern Ecuadorian Andes | url =https://hal.archives-ouvertes.fr/hal-01066834/document | journal = Climate of the Past | volume = 9 | issue = 1| pages = 307–321 | doi = 10.5194/cp-9-307-2013 | bibcode = 2013CliPa...9..307L | doi-access = free }}

A reconstruction, based on ice cores, found that the MWP could be distinguished in tropical South America from about 1050 to 1300 and was followed in the 15th century by the LIA. Peak temperatures did not rise as to the level of the late 20th century, which were unprecedented in the area during the study period of 1600 years.{{cite journal |doi=10.1029/2009JD012603 |title=Ammonium concentration in ice cores: A new proxy for regional temperature reconstruction? |year=2010 |last1=Kellerhals |first1=T. |last2=Brütsch |first2=S. |last3=Sigl |first3=M. |last4=Knüsel |first4=S. |last5=Gäggeler |first5=H. W. |last6=Schwikowski |first6=M. |journal=Journal of Geophysical Research |volume=115 |issue=D16 |pages=D16123 |bibcode=2010JGRD..11516123K|url=https://www.dora.lib4ri.ch/psi/islandora/object/psi%3A23618 |url-access=subscription }}

= East Asia =

Ge et al. studied temperatures in China for the past 2000 years and found high uncertainty prior to the 16th century but good consistency over the last 500 years highlighted by the two cold periods, 1620s–1710s and 1800s–1860s, and the 20th-century warming. They also found that the warming from the 10th to the 14th centuries in some regions might be comparable in magnitude to the warming of the last few decades of the 20th century, which was unprecedented within the past 500 years.{{cite journal |bibcode=2010GeoRL..37.3703G |title=Temperature variation through 2000 years in China: An uncertainty analysis of reconstruction and regional difference |url=https://www.researchgate.net/publication/248815851 |last1=Ge |first1=Q.-S. |last2=Zheng |first2=J.-Y. |last3=Hao |first3=Z.-X. |last4=Shao |first4=X.-M. |last5=Wang |first5=Wei-Chyung |last6=Luterbacher |first6=Juerg |volume=37 |year=2010 |pages=03703 |journal=Geophysical Research Letters |doi=10.1029/2009GL041281 |issue=3 |s2cid=129457163 |doi-access=free |access-date=18 June 2023}} Generally, a warming period was identified in China, coinciding with the MWP, using multi-proxy data for temperature. However, the warming was inconsistent across China. Significant temperature change, from the MWP to LIA, was found for northeast and central-east China but not for northwest China and the Tibetan Plateau.{{Cite journal |last1=Hao |first1=Zhixin |last2=Wu |first2=Maowei |last3=Liu |first3=Yang |last4=Zhang |first4=Xuezhen |last5=Zheng |first5=Jingyun |date=2020-01-01 |title=Multi-scale temperature variations and their regional differences in China during the Medieval Climate Anomaly |journal=Journal of Geographical Sciences |language=en |volume=30 |issue=1 |pages=119–130 |doi=10.1007/s11442-020-1718-7 |s2cid=209843427 |issn=1861-9568|doi-access=free |bibcode=2020JGSci..30..119H }} During the MWP, the East Asian Summer Monsoon (EASM) was the strongest it has been in the past millennium{{Cite journal |last1=Zhou |first1=XiuJi |last2=Zhao |first2=Ping |last3=Liu |first3=Ge |last4=Zhou |first4=TianJun |date=24 September 2011 |title=Characteristics of decadal-centennial-scale changes in East Asian summer monsoon circulation and precipitation during the Medieval Warm Period and Little Ice Age and in the present day |journal=Chinese Science Bulletin |language=en |volume=56 |issue=28–29 |page=3003 |doi=10.1007/s11434-011-4651-4 |issn=1001-6538 |doi-access=free |bibcode=2011ChSBu..56.3003Z }} and was highly sensitive to the El Niño Southern Oscillation (ENSO).{{cite journal |last1=Zhang |first1=Zhenqiu |last2=Liang |first2=Yijia |last3=Wang |first3=Yongjin |last4=Duan |first4=Fucai |last5=Yang |first5=Zhou |last6=Shao |first6=Qingfeng |last7=Liu |first7=Shushuang |date=15 December 2021 |title=Evidence of ENSO signals in a stalagmite-based Asian monsoon record during the medieval warm period |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018221004995 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=584 |page=110714 |doi=10.1016/j.palaeo.2021.110714 |bibcode=2021PPP...58410714Z |s2cid=239270259 |access-date=8 July 2023|url-access=subscription }} The Mu Us Desert witness increased moisture in the MWP.{{Cite journal |last1=Liu |first1=Xiaokang |last2=Lu |first2=Ruijie |last3=Jia |first3=Feifei |last4=Chen |first4=Lu |last5=Li |first5=Tengfei |last6=Ma |first6=Yuzhen |last7=Wu |first7=Yongqiu |date=5 March 2018 |title=Holocene water-level changes inferred from a section of fluvio-lacustrine sediments in the southeastern Mu Us Desert, China |url=https://linkinghub.elsevier.com/retrieve/pii/S1040618216302518 |journal=Quaternary International |language=en |volume=469 |pages=58–67 |doi=10.1016/j.quaint.2016.12.032 |bibcode=2018QuInt.469...58L |access-date=23 September 2023|url-access=subscription }} Peat cores from peatland in southeast China suggest changes in the EASM and ENSO are responsible for increased precipitation in the region during the MWP.{{Cite journal |last1=Sun |first1=Jia |last2=Ma |first2=Chunmei |last3=Zhou |first3=Bin |last4=Jiang |first4=Jiawei |last5=Zhao |first5=Cheng |date=2021 |title=Biogeochemical evidence for environmental and vegetation changes in peatlands from the middle Yangtze river catchment during the medieval warm period and little ice Age |url=http://journals.sagepub.com/doi/10.1177/09596836211025966 |journal=The Holocene |language=en |volume=31 |issue=10 |pages=1571–1581 |bibcode=2021Holoc..31.1571S |doi=10.1177/09596836211025966 |issn=0959-6836 |s2cid=237010950|url-access=subscription }} However, other sites in southern China show aridification and not humidification during the MWP, showing that the MWP's influence was highly spatially heterogeneous.{{Cite journal |last1=Chu |first1=Peter C. |last2=Li |first2=Hong-Chun |last3=Fan |first3=Chenwu |last4=Chen |first4=Yong-Heng |date=11 December 2012 |title=Speleothem evidence for temporal–spatial variation in the East Asian Summer Monsoon since the Medieval Warm Period |url=https://onlinelibrary.wiley.com/doi/10.1002/jqs.2579 |journal=Journal of Quaternary Science |language=en |volume=27 |issue=9 |pages=901–910 |doi=10.1002/jqs.2579 |bibcode=2012JQS....27..901C |s2cid=9727512 |issn=0267-8179 |access-date=23 September 2023|hdl=10945/36182 |hdl-access=free }} Modelling evidence suggests that EASM strength during the MWP was low in early summer but very high during late summer.{{Cite journal |last1=Kamae |first1=Youichi |last2=Kawana |first2=Toshi |last3=Oshiro |first3=Megumi |last4=Ueda |first4=Hiroaki |date=4 August 2017 |title=Seasonal modulation of the Asian summer monsoon between the Medieval Warm Period and Little Ice Age: a multi model study |journal=Progress in Earth and Planetary Science |language=en |volume=4 |issue=1 |page=22 |doi=10.1186/s40645-017-0136-7 |issn=2197-4284 |doi-access=free |bibcode=2017PEPS....4...22K |hdl=2241/00148518 |hdl-access=free }}

In far eastern Russia, continental regions experienced severe floods during the MWP while nearby islands experienced less precipitation leading to a decrease in peatland. Pollen data from this region indicates an expansion of warm climate vegetation with an increasing number of broadleaf and decreasing number of coniferous forests.{{Cite journal |last1=Razjigaeva |first1=Nadezhda G. |last2=Ganzey |first2=Larisa A. |last3=Bazarova |first3=Valentina B. |last4=Arslanov |first4=Khikmatulla A. |last5=Grebennikova |first5=Tatiana A. |last6=Mokhova |first6=Ludmila M. |last7=Belyanina |first7=Nina I. |last8=Lyaschevskaya |first8=Marina S. |date=10 June 2019 |title=Landscape response to the Medieval Warm Period in the South Russian Far East |url=https://www.sciencedirect.com/science/article/pii/S1040618218302866 |journal=Quaternary International |series=The 3rd ASQUA Conference (Part II) |language=en |volume=519 |pages=215–231 |bibcode=2019QuInt.519..215R |doi=10.1016/j.quaint.2018.12.006 |issn=1040-6182 |s2cid=134246491 |access-date=18 June 2023|url-access=subscription }}

Adhikari and Kumon (2001), investigating sediments in Lake Nakatsuna, in central Japan, found a warm period from 900 to 1200 that corresponded to the MWP and three cool phases, two of which could be related to the LIA.{{cite journal |last1=Adhikari |first1=D. P. |last2=Kumon |first2=F. |year=2001 |title=Climatic changes during the past 1300 years as deduced from the sediments of Lake Nakatsuna, central Japan |journal=Limnology |volume=2 |issue=3 |pages=157 |doi=10.1007/s10201-001-8031-7 |bibcode=2001Limno...2..157A |s2cid=20937188}} Other research in northeastern Japan showed that there was one warm and humid interval, from 750 to 1200, and two cold and dry intervals, from 1 to 750 and from 1200 to now.{{cite journal |last1=Yamada |first1=Kazuyoshi |last2=Kamite |first2=Masaki |last3=Saito-Kato |first3=Megumi |last4=Okuno |first4=Mitsuru |last5=Shinozuka |first5=Yoshitsugu |last6=Yasuda |first6=Yoshinori |date=June 2010 |title=Late Holocene monsoonal-climate change inferred from Lakes Ni-no-Megata and San-no-Megata, northeastern Japan |url=https://www.researchgate.net/publication/248478987 |journal=Quaternary International |volume=220 |issue=1–2 |pages=122–132 |bibcode=2010QuInt.220..122Y |doi=10.1016/j.quaint.2009.09.006 |access-date=8 July 2023}}

= South Asia =

The Indian Summer Monsoon (ISM) was also enhanced during the MWP with a temperature driven change to the Atlantic Multi-decadal Oscillation (AMO),{{Cite journal |last1=Naidu |first1=Pothuri Divakar |last2=Ganeshram |first2=Raja |last3=Bollasina |first3=Massimo A. |last4=Panmei |first4=Champoungam |last5=Nürnberg |first5=Dirk |last6=Donges |first6=Jonathan F. |date=2020-01-28 |title=Coherent response of the Indian Monsoon Rainfall to Atlantic Multi-decadal Variability over the last 2000 years |journal=Scientific Reports |language=en |volume=10 |issue=1 |pages=1302 |bibcode=2020NatSR..10.1302N |doi=10.1038/s41598-020-58265-3 |issn=2045-2322 |pmc=6987308 |pmid=31992786}} bringing more precipitation to India.{{Cite journal |last1=Naidu |first1=Pothuri Divakar |last2=Ganeshram |first2=Raja |last3=Bollasina |first3=Massimo A. |last4=Panmei |first4=Champoungam |last5=Nürnberg |first5=Dirk |last6=Donges |first6=Jonathan F. |date=28 January 2020 |title=Coherent response of the Indian Monsoon Rainfall to Atlantic Multi-decadal Variability over the last 2000 years |journal=Scientific Reports |language=en |volume=10 |issue=1 |pages=1302 |bibcode=2020NatSR..10.1302N |doi=10.1038/s41598-020-58265-3 |issn=2045-2322 |pmc=6987308 |pmid=31992786}} Vegetation records in Lahaul in Himachal Pradesh confirm a warm and humid MWP from 1,158 to 647 BP.{{Cite journal |last1=Rawat |first1=Suman |last2=Gupta |first2=Anil K. |last3=Sangode |first3=S. J. |last4=Srivastava |first4=Priyeshu |last5=Nainwal |first5=H.C. |date=15 April 2015 |title=Late Pleistocene–Holocene vegetation and Indian summer monsoon record from the Lahaul, Northwest Himalaya, India |url=https://linkinghub.elsevier.com/retrieve/pii/S0277379115000566 |journal=Quaternary Science Reviews |language=en |volume=114 |pages=167–181 |doi=10.1016/j.quascirev.2015.01.032 |bibcode=2015QSRv..114..167R |access-date=23 September 2023|url-access=subscription }} Pollen from Madhya Pradesh dated to the MWP provides further direct evidence for increased monsoonal precipitation.{{Cite journal |last1=Quamar |first1=M. F. |last2=Chauhan |first2=M. S. |date=19 March 2014 |title=Signals of Medieval Warm Period and Little Ice Age from southwestern Madhya Pradesh (India): A pollen-inferred Late-Holocene vegetation and climate change |url=https://www.sciencedirect.com/science/article/pii/S1040618213003947 |journal=Quaternary International |series=Holocene Palynology and Tropical Paleoecology |volume=325 |pages=74–82 |doi=10.1016/j.quaint.2013.07.011 |bibcode=2014QuInt.325...74Q |issn=1040-6182 |access-date=23 September 2023|url-access=subscription }} Multi-proxy records from Pookode Lake in Kerala also reflect the warmth of the MWP.{{Cite journal |last1=Veena |first1=M.P. |last2=Achyuthan |first2=Hema |last3=Eastoe |first3=Christopher |last4=Farooqui |first4=Anjum |date=19 March 2014 |title=A multi-proxy reconstruction of monsoon variability in the late Holocene, South India |url=https://linkinghub.elsevier.com/retrieve/pii/S1040618213007982 |journal=Quaternary International |language=en |volume=325 |pages=63–73 |doi=10.1016/j.quaint.2013.10.026 |bibcode=2014QuInt.325...63V |access-date=23 September 2023|url-access=subscription }}

= Middle East =

Sea surface temperatures in the Arabian Sea increased during the MWP, owing to a strong monsoon.{{Cite journal |last1=Gupta |first1=Anil K. |last2=Anderson |first2=David M. |last3=Overpeck |first3=Jonathan T. |date=23 January 2003 |title=Abrupt changes in the Asian southwest monsoon during the Holocene and their links to the North Atlantic Ocean |url=https://www.nature.com/articles/nature01340 |journal=Nature |language=en |volume=421 |issue=6921 |pages=354–357 |doi=10.1038/nature01340 |pmid=12540924 |bibcode=2003Natur.421..354G |s2cid=4304234 |issn=1476-4687|url-access=subscription }} During the MWP, the Arabian Sea exhibited heightened biological productivity.{{Cite journal |last1=Agnihotri |first1=Rajesh |last2=Dutta |first2=Koushik |last3=Bhushan |first3=Ravi |last4=Somayajulu |first4=B. L. K |date=15 May 2002 |title=Evidence for solar forcing on the Indian monsoon during the last millennium |url=https://www.sciencedirect.com/science/article/pii/S0012821X02005307 |journal=Earth and Planetary Science Letters |volume=198 |issue=3 |pages=521–527 |doi=10.1016/S0012-821X(02)00530-7 |bibcode=2002E&PSL.198..521A |issn=0012-821X |access-date=30 September 2023|url-access=subscription }} The Arabian Peninsula, already extremely arid in the present day, was even drier during the MWP. Prolonged drought was a mainstay of the Arabian climate until around 660 BP, when this hyperarid interval was terminated.{{cite journal |last1=Kalman |first1=Akos |last2=Katz |first2=Timor |last3=Hill |first3=Paul |last4=Goodman-Tchernov |first4=Beverly |date=21 March 2020 |title=Droughts in the desert: Medieval Warm Period associated with coarse sediment layers in the Gulf of Aqaba-Eilat, Red Sea |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/sed.12737 |journal=Sedimentology |volume=67 |issue=6 |pages=3152–3166 |doi=10.1111/sed.12737 |s2cid=216335544 |access-date=18 June 2023|url-access=subscription }}

= Oceania =

There is an extreme scarcity of data from Australia for both the MWP and the LIA. However, evidence from wave-built shingle terraces for a permanently-full Lake Eyre{{cite report|author=Allen, Robert J. |title=The Australasian Summer Monsoon, Teleconnections, and Flooding in the Lake Eyre Basin |publisher=Royal Geographical Society of Australasia, S.A. Branch |year=1985|page=43|isbn=978-0-909112-09-7}} during the 9th and the 10th centuries is consistent with a La Niña-like configuration, but the data are insufficient to show how lake levels varied from year to year or what climatic conditions elsewhere in Australia were like.

A 1979 study from the University of Waikato found,{{cite journal |doi=10.1038/279315a0 |title=Short-term climate change and New Zealand temperatures during the last millennium |year=1979 |last1=Wilson |first1=A. T. |last2=Hendy |first2=C. H. |last3=Reynolds |first3=C. P. |journal=Nature |volume=279 |issue=5711 |pages=315|bibcode = 1979Natur.279..315W|s2cid=4302802 }}

{{blockquote |text=Temperatures derived from an ¹⁸O/¹⁶O profile through a stalagmite found in a New Zealand cave ({{coord |40.67|S|172.43|E}}) suggested the Medieval Warm Period to have occurred between [... about {{CE|1050–1400}}] and to have been {{convert|0.75|C-change|1|disp=sqbr}} warmer than the Current Warm Period.}}

More evidence in New Zealand is from an 1100-year tree-ring record.{{cite journal |bibcode=2002GeoRL..29.1667C |title=Evidence for a 'Medieval Warm Period' in a 1,100 year tree-ring reconstruction of past austral summer temperatures in New Zealand |last1=Cook |first1=Edward R. |last2=Palmer |first2=Jonathan G. |last3=d'Arrigo |first3=Rosanne D. |author-link3=Rosanne D'Arrigo|volume=29 |year=2002 |pages=12 |journal=Geophysical Research Letters |doi=10.1029/2001GL014580 |issue=14|s2cid=34033855 |doi-access=}}

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{{cite book | first=Emmanuel Le Roy | last=Ladurie | title=Times of Feast, Times of Famine: a History of Climate Since the Year 1000 | isbn=978-0-374-52122-6 | publisher=Farrar Straus & Giroux | year=1971 }}{{Page needed|date=March 2012}}

{{cite journal |doi=10.1038/369546a0 |title=Extreme and persistent drought in California and Patagonia during mediaeval time |year=1994 |last1=Stine |first1=Scott |journal=Nature |volume=369 |issue=6481 |pages=546–549|bibcode = 1994Natur.369..546S |s2cid=4315201 }}

{{cite journal |doi=10.1126/science.1177303 |title=Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly |year=2009 |last1=Mann |first1=M. E. |last2=Zhang |first2=Z. |last3=Rutherford |first3=S. |last4=Bradley |first4=R. S. |last5=Hughes |first5=M. K. |last6=Shindell |first6=D. |last7=Ammann |first7=C. |last8=Faluvegi |first8=G. |last9=Ni |first9=F.|display-authors=3 |journal=Science |volume=326 |issue=5957 |pages=1256–60 |pmid=19965474|bibcode = 2009Sci...326.1256M |s2cid=18655276 |url=http://www.geo.umass.edu/climate/papers2/Mann2009.pdf }}

{{cite journal |doi=10.1126/science.1090372 |title=CLIMATE CHANGE: Climate in Medieval Time |year=2003 |last1=Bradley |first1=R. S. |journal=Science |volume=302 |issue=5644 |pages=404–5 |pmid=14563996 |last2=Hughes |first2=MK |last3=Diaz |first3=HF|s2cid=130306134 }}

{{cite journal |doi=10.1579/0044-7447-29.1.51 |title=How Warm Was the Medieval Warm Period? |year=2000 |last1=Crowley |first1=Thomas J. |last2=Lowery |first2=Thomas S. |journal=Ambio: A Journal of the Human Environment |volume=29 |issue=1 |pages=51–54|bibcode=2000Ambio..29...51C |s2cid=86527510 }}

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External links

[http://www.historicalclimatology.com HistoricalClimatology.com], further links, resources, and relevant news, updated 2016
[http://www.climatehistory.net Climate History Network]
[https://web.archive.org/web/20090318081017/http://agu.org/revgeophys/mayews01/node5.html The Little Ice Age and Medieval Warm Period] at the American Geophysical Union

Category:950 establishments

Category:1250 disestablishments

Category:10th century

Category:11th century

Category:12th century

Category:13th century

Category:History of climate variability and change

Category:Holocene