- The present-day baseline used for comparison to the temperatures in the Medieval warm period is 1960-1990. ...
- The Medieval warm period is an asynchronous regional warming caused by natural (not human-driven) climatic variation, whereas we are facing a homogeneous and global warming caused by human activity releasing too much greenhouse gas into the atmosphere.
Why did the Medieval Warm Period happen?
The medieval warming period was essentially a lull between cooling events, specifically large volcanic eruptions. Large volcanic eruptions spew ash into the atmosphere that reflects heat from the sun, causing cooling. In 535, a cooling period occurred, thought to have been caused by the eruption of Tierra Blanca Joven in El Salvador.
What caused the Minoan warm period?
The Minoan civilization was an Aegean Bronze Age civilization that arose on the island of Crete and other Aegean islands and flourished from approximately 3650 BC to 1400 BC. Clearly, sea travel must have emerged for the people to migrate from Turkey to Crete. Civilization appeared to emerge with this warming period.
What event started the medieval period?
- September 4th, 476 AD- The Roman Emperor Romulus Augustus defeated by the leader of German Scirii and Heruli tribes, Odoacer.
- 481 AD- The Frankish tribes are united by Clovis after he became the king of Franks by defeating the Visigoths in the Battle of Vouille.
- 529 AD- The Code of Civil Law published by Justinian 1. ...
Was there a Medieval Warm Period?
medieval warm period (MWP), also called medieval warm epoch or little climatic optimum, brief climatic interval that is hypothesized to have occurred from approximately 900 ce to 1300 (roughly coinciding with the Middle Ages in Europe ), in which relatively warm conditions are said to have prevailed in various parts of the world, though predominantly in the Northern Hemisphere from Greenland eastward through Europe and parts of Asia.
What happened in the Medieval Warm Period?
During the Medieval Warm Period, roughly from 800 to 1200 AD, temperatures rose a few degrees above average. That warming has been connected to improved crop yields in parts of Europe, and the temporary Viking occupation of Greenland.
When was the medieval warming period?
950 AD – 1250Medieval Warm Period / Period
Was the medieval warming period warmer than today?
The Medieval Warm Period was approximately 1 °C warmer than present, and the Little Ice Age 0.6 °C cooler than present, in central Greenland.
What is the Medieval Warming Period and the Little Ice Age?
The Medieval Warm Period (MWP) is generally considered to be an episode of above average temperatures for the years 950–1200 ad, while the Little Ice Age (LIA) was an episode of below average temperatures from 1550 to 1850 ad (Brazdil et al. 2005).
What was the hottest period in human history?
One of the warmest times was during the geologic period known as the Neoproterozoic, between 600 and 800 million years ago. Conditions were also frequently sweltering between 500 million and 250 million years ago.
When was the last warming period on Earth?
Earth has experienced cold periods (or “ice ages”) and warm periods (“interglacials”) on roughly 100,000-year cycles for at least the last 1 million years. The last of these ices ended around 20,000 years ago.
What year was the Little Ice Age?
1303 – 1850Little Ice Age / Period
Was the Earth hotter in Roman times?
The trend came about because of reduced solar heating caused by changes to the Earth's orbit known as Milankovitch wobbles, says Esper. His results suggest the Roman world was 0.6 °C warmer than previously thought – enough to make grape vines in northern England a possibility.
Has temperature risen in 100 years?
Over the last century, the average surface temperature of the Earth has increased by about 1.0o F. The eleven warmest years this century have all occurred since 1980, with 1995 the warmest on record.
Will there be a mini ice age in 2030?
"Pink elephant in the room" time: There is no impending “ice age” or "mini ice age" if there's a reduction in the Sun's energy output in the next several decades. Through its lifetime, the Sun naturally goes through changes in energy output.
What are some of the characteristics of the medieval warming period?
It usually brings clouds and rain in the western tropical Pacific while making regions in the eastern tropical Pacific relatively drier and cooler. During the Medieval warm period, an increase in solar radiation and decrease in volcanic eruptions created a La Niña-like event that changed the usual patterns.
Are we due a mini ice age?
Scientists have predicted that Earth is 15 years away from a "mini ice age," The Telegraph reports. Using a new model of the sun's activity, the solar researchers estimate that in the 2030s the movements of two waves of fluids within the star will lead to a 60% reduction in solar activity.
Where did the Medieval Warm Period occur?
Despite being predominantly recorded in Europe, south-western North America and in some tropical regions, the Medieval warm period affected both the northern and southern hemispheres. But the temperature increase was not universal, varying across regions of the world, and did not happen simultaneously everywhere.
What year was the Little Ice Age?
1303 – 1850Little Ice Age / Period
When was the Roman warm period?
The Empire coincided with a 500-year period, from AD 1 to AD 500, that was the warmest period of the last 2,000 years in the almost completely land-locked sea. The climate later progressed towards colder and arid conditions that coincided with the historical fall of the Empire, scientists claim.
How warm was Greenland during the Medieval Warm Period?
Overall, the climate was about 1.5-degrees Celsius warmer than the surrounding cooling centuries. This warmer period was similar to southern Greenland's temperatures today, which hover around 10-degrees Celsius (50-degrees Fahrenheit) in summer.
What makes the medieval warm period irrelevant?
Despite the uncertainties, the climate characteristics of the Medieval warm period make it an irrelevant analogue for the magnitude of climate change we are facing.
What was the Medieval Warm Period?
The Medieval warm period was by and large a regional event. Its presence or absence reflects a redistribution of heat around the planet, and this suggests drivers other than a global increase in atmospheric greenhouse gases such as carbon dioxide.
Why does the medieval warm period seem to fit the bill?
This evokes the idea that if natural global warming and all its effects occurred in the past without humans causing them , then perhaps we are not responsible for this one. And it does not really matter because if we survived one in the past, then we can surely survive one now.
What caused the wetter conditions in Australasia?
Stronger trade winds pushing more warm water towards Asia created wetter conditions in Australasia, droughts in the southern US and South and Central America, and heavy rains and flooding in the Pacific Northwest and Canada.
What was the beginning of the conquests of Genghis Khan?
The early 13th Century marked the beginning of the conquests of Genghis Khan and his Mongol hordes. Read more: Wet climate helped Genghis Khan conquer Asia. With sea ice and land ice in the Arctic shrinking with the rising temperatures, new lands became accessible and Vikings travelled farther north than before.
How does the eastern Pacific affect the climate?
This recurring climate pattern of winds and sea-surface temperatures over the tropical eastern Pacific affects the climate and weather of much of the tropics and subtropics. It usually brings clouds and rain in the western tropical Pacific while making regions in the eastern tropical Pacific relatively drier and cooler.
What is climate explained?
Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.
What is the medieval warm period?
Global average temperatures show that the Medieval Warm Period was not a planet-wide phenomenon. The Medieval Warm Period ( MWP) also known as the Medieval Climate Optimum, or Medieval Climatic Anomaly was a time of warm climate in the North Atlantic region lasting from c. 950 to c. 1250. It was likely related to warming elsewhere ...
When was the warm period in the Middle Ages?
The Medieval Warm Period (MWP) is generally thought to have occurred from c. 950 – c. 1250, during the European Middle Ages. 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 c. 1200 and around c. 1600. He proposed, "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 c. 1000 – c. 1200 AD, and was followed by a decline of temperature levels till between c. 1500 and c. 1700 the coldest phase since the last ice age occurred."
How many times did Alaska experience warm weather?
Alaska experienced three time intervals of comparable warmth: 1–300, 850–1200, and post-1800. Knowledge of the North American Medieval Warm Period has been useful in dating occupancy periods of certain Native American habitation sites, especially in arid parts of the western United States. MWP droughts may have also impacted Native American ...
How long has Japan been warm?
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. 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.
What was the warm period called?
The warm period became known as the Medieval Warm Period, and the cold period was called the Little Ice Age (LIA). However, that view was questioned by other researchers. The IPCC First Assessment Report of 1990 discussed the "Medieval Warm Period around 1000 AD (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 "late tenth to early thirteenth centuries (about AD 950-1250) appear to have been exceptionally warm in western Europe, Iceland and Greenland." The IPCC Third Assessment Report from 2001 summarized newer research: "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."
How long did the dry period last in the Hudson Valley?
Sediments in Piermont Marsh of the lower Hudson Valley show a dry Medieval Warm period from 800 to 1300. Prolonged droughts affected many parts of the western United States and especially eastern California and the west of Great Basin. Alaska experienced three time intervals of comparable warmth: 1–300, 850–1200, and post-1800.
When was the warm period in New Zealand?
A 1979 study from the University of Waikato found, "Temperatures derived from an 18 O/ 16 O profile through a stalagmite found in a New Zealand cave (40.67°S, 172.43°E) suggested the Medieval Warm Period to have occurred between AD c. 1050 and c. 1400 and to have been 0.75 °C warmer than the Current Warm Period." More evidence in New Zealand is from an 1100-year tree-ring record.
What were the effects of the Medieval Warm Period?
During the Medieval warm period, an increase in solar radiation and decrease in volcanic eruptions created a La Niña-like event that changed the usual patterns. Stronger trade winds pushing more warm water towards Asia created wetter conditions in Australasia, droughts in the southern US and South and Central America, and heavy rains and flooding in the Pacific Northwest and Canada.
What were the mechanisms driving the medieval warm period?
Mechanisms driving the Medieval warm period. The Medieval warm period was by and large a regional event. Its presence or absence reflects a redistribution of heat around the planet, and this suggests drivers other than a global increase in atmospheric greenhouse gases such as carbon dioxide. The most likely cause of the regional changes in ...
Why does the medieval warm period seem to fit the bill?
This evokes the idea that if natural global warming and all its effects occurred in the past without humans causing them , then perhaps we are not responsible for this one. And it does not really matter because if we survived one in the past, then we can surely survive one now.
What were the effects of the warm climate on the Earth?
The warm conditions during this period brought many benefits to Earth's plant and animal life, but in some other parts of the world, people's lives were instead made worse by intense droughts.
Where did the Medieval Warm Period occur?
Despite being predominantly recorded in Europe, south-western North America and in some tropical regions, the Medieval warm period affected both the northern and southern hemispheres. But the temperature increase was not universal, varying across regions of the world, and did not happen simultaneously everywhere.
How does the eastern Pacific affect the climate?
This recurring climate pattern of winds and sea-surface temperatures over the tropical eastern Pacific affects the climate and weather of much of the tropics and subtropics. It usually brings clouds and rain in the western tropical Pacific while making regions in the eastern tropical Pacific relatively drier and cooler.
What was the beginning of the 13th century?
The early 13th Century marked the beginning of the conquests of Genghis Khan and his Mongol hordes. Credit: Wikimedia, CC BY-SA. With sea ice and land ice in the Arctic shrinking with the rising temperatures, new lands became accessible and Vikings traveled farther north than before.
When did the sun start warming?
The numbers line up well with the warming that began around 20,000 years ago . Hotter sun not required. Only the Earth’s orbit, though we can never been entirely certain and an extended solar sunspot cycle may have played some role, but likely a smaller role.
What causes glacial periods?
It’s Northern Hemisphere insolation during summer months that causes and ends glacial periods. Solar minimums and maximums may play a role, but a smaller role. The rise and fall of glacial periods (called ice ages by some) matches Earth’s orbital cycles. There’s 2.6 million years of geological evidence to support that.
What is the most important thing about the Northern Hemisphere?
Northern Hemisphere summers are the most important. When the summer’s are hot, ice melts. When the summers are cold, ice, which falls in the winter, doesn’t melt. It’s that simple.
What was the temperature during the Holocene?
Temperatures peaked about 0,2 to 0,6 K above modern temperatures during the “Holocene Climate Optimum”, and were also warmer than present during the “Medieval Warm Period” , cooled between 0,2 and 0,7K below current temperatures during the “Li
When the Sun is tilted, the Sun is higher in the summer and lower in the winter?
When the Axial Tilt is 24.5 degrees, the Sun is higher in the summer and lower in the winter in both hemispheres. The Axial tilt was at it’s maximum about 11,700 years ago, but the ice melt occurs not just at the maximum, but as it approaches the maximum and as it moves away, think between the 10 O’clock and 2′Oclock periods or about 1/3rd of the cycle, between 18,500 years ago and 4,900 years ago, give or take. That was the Axial tilt driven warm period, which coincides with a lot of the ice melt.
Was the Little Ice Age a real ice age?
If talking about the “little Ice age”, it was a period of cold weather in north west Europe. It was not global, as a real ice age, and may have been caused by a decrease in Gulf stream strength. A decrease that in turn could possibly have been caused by melt-water from Greenland or northern Canada. If so the end was due to restoration of the Gulf stream that in turn was triggered by reduced melting on Greenland.
Was there a medieval warm period?
Well, for a start, there wasn’t really a “medieval warm period”. There were several events during which some parts of the planet were warmer but these did not coincide, really there were three different ones each separated by a century or so, in each of these while some areas were warmer others were cooler and at no point was the whole earth significantly warmer than average. All the planet experienced some warming during a period of aroud 500 years but thise wan’t all together - three different regions had their own warming periods which did not overlap with the others. A detailed meta-analys
When was the medieval warm period?
The information available places the “Medieval Warm Period” (MWP) roughly between the 10th and 13th centuries (Lamb, 1977, 1982 ). During this period, cultivation limits were higher in elevation and farther north than at present, and the tree-line migrated upward in parts of central and northern Europe.
Which region experienced a warmer climate than the present?
D., analysis of historical, botanical and paleoclimatic records suggests that parts of Europe, North America and the North Atlantic experienced a relatively warmer climate than the present.
How cold was the last glacial maximum?
The Wisconsin–Holocene deglacial transition was very large in central Greenland ( Figure 2 ), at least 15 °C between the mean glacial climate and the mean Holocene, with the Last Glacial Maximum being at least 20 °C colder than present ( Cuffey et al., 1995; Johnsen et al., 1995; Cuffey and Clow, 1997; Dahl-Jensen et al., 1998 ). Such extremely low surface temperatures appear to be consistent with the large expansion of continental ice sheets and sea ice extent during the glacial climate, coupled with the global reduction in atmospheric greenhouse gas concentrations.
What was the most recent cold event in the Holocene?
The most recent Holocene cold event is the Little Ice Age (LIA; see Figs. 2 and 3). This event really consisted of two cold periods, the first of which followed the Medieval Warm Period (MWP) that ended ∼ 1000 years ago. This first cold period is often referred to as the Medieval Cold Period (MCP) or LIAb. The MCP played a role in extinguishing Norse colonies on Greenland and caused famine and mass migration in Europe. It started gradually before 1200 CE and ended at about 1650 CE. This second cold period, may have been the most rapid and the largest change in the North Atlantic during the Holocene, as suggested from ice-core and deep-sea sediment records. The Little Ice Age events are characterized by a drop in temperature of 0.5–1 °C in Greenland and sea surface temperature decreases of 4 °C off the coast of west Africa and 2 °C off the Bermuda Rise (see Fig. 3 ).
What was the first cold period?
This first cold period is often referred to as the Medieval Cold Period (MCP) or LIAb. The MCP played a role in extinguishing Norse colonies on Greenland and caused famine and mass migration in Europe. It started gradually before 1200 CE and ended at about 1650 CE.
Did Greenland have a warm period?
In contrast to some other regions of the Arctic, such as northern Alaska and Siberia, Greenland did not have renewed warming through the latter decades of the twentieth century. The Medieval Warm Period was approximately 1 °C warmer than present, and the Little Ice Age 0.6 °C cooler than present, in central Greenland.
Is Greenland warmer than the Holocene?
These also reveal a persistent Climatic Optimum through the early–mid Holocene with temperatures at least 2 °C warmer than present (in central Greenland), terminating in cooling between 4 and 2 ka BP ( Cuffey and Clow, 1997; Dahl-Jensen et al., 1998 ). All of these Holocene variations appear to have been larger in southern than in central Greenland ( Dahl-Jensen et al., 1998 ).
When was the medieval warm period?
Medieval Warm Period. The Medieval Warm Period (MWP) occurred around one thousand years ago. This is known by examinations of ice core records and multiple proxy models from multiple interrelated disciplines. There is no controversy about the existence of the Medieval Warm Period scientifically or in the popular press.
What is the lead scientific theory of the oceanic heat?
The lead scientific theory is that it was a naturally occurring event, and data indicate it was a Dansgaard-Oeschger (D-O) event. These events seem to occur on 1470 year intervals with periodic skips in interval. Generally this is an overturn of the oceanic heat content between the northern and southern hemispheres.
Was the MWP a global event?
The current scientific understanding is that the MWP was not 'as much' of a global event as it was a see-saw of the global heat content between the two hemispheres. Evidence also indicates that there was a slight global rise in temperatures.
What makes the medieval warm period irrelevant?
Despite the uncertainties, the climate characteristics of the Medieval warm period make it an irrelevant analogue for the magnitude of climate change we are facing.
What were the effects of the Medieval Warm Period?
During the Medieval warm period, an increase in solar radiation and decrease in volcanic eruptions created a La Niña-like event that changed the usual patterns. Stronger trade winds pushing more warm water towards Asia created wetter conditions in Australasia, droughts in the southern US and South and Central America, and heavy rains and flooding in the Pacific Northwest and Canada.
Why does the medieval warm period seem to fit the bill?
This evokes the idea that if natural global warming and all its effects occurred in the past without humans causing them , then perhaps we are not responsible for this one. And it does not really matter because if we survived one in the past, then we can surely survive one now.
How does the eastern Pacific affect the climate?
This recurring climate pattern of winds and sea-surface temperatures over the tropical eastern Pacific affects the climate and weather of much of the tropics and subtropics. It usually brings clouds and rain in the western tropical Pacific while making regions in the eastern tropical Pacific relatively drier and cooler.
Where did the Medieval Warm Period occur?
Despite being predominantly recorded in Europe, south-western North America and in some tropical regions, the Medieval warm period affected both the northern and southern hemispheres. But the temperature increase was not universal, varying across regions of the world, and did not happen simultaneously everywhere.
What is the most likely cause of the regional changes in temperature?
The most likely cause of the regional changes in temperature was related to a modification of the El Niño–Southern Oscillation.
What was the beginning of the conquests of Genghis Khan?
The early 13th Century marked the beginning of the conquests of Genghis Khan and his Mongol hordes. Read more: Wet climate helped Genghis Khan conquer Asia. With sea ice and land ice in the Arctic shrinking with the rising temperatures, new lands became accessible and Vikings travelled farther north than before.
What is the warm period of the medieval era?
Today Lamb's Medieval Warm Epoch has become widely known as the Medieval Warm Period (MWP). Of course, history in the Americas had followed a very different trajectory; and would continue to do so until Columbus crossed the Atlantic in 1492 and 'Old' and 'New' worlds finally met. (See also Note at bottom of Mesoamericans page.)
Who wrote the medieval warm period?
This timespan is necessary both to provide explanation and set Hubert Lamb's Medieval Warm Period (MWP) in a context. All that is below was unknown to Lamb when he wrote ' Climate, History and the Modern World ' (1982). Lamb was the first to use the term Medieval Warm Epoch.
What is the most striking aspect of the period of American climate, between the 2nd and 16th Centuries,?
The most striking aspect of the period of American climate, between the 2nd and 16th Centuries, is the incidence, extent, prevalence, duration and severity of drought s, throughout the Americas; particularly - but by no means exclusively - over western and central regions of the Americas.
When did the Maya drought start?
In the Maya lowlands, in northern Guatemala, a great drought slowly developed between 125–210 AD. This was a very long dry spell (85 years) of slowly decreasing precipitation.
When did the Pacific Ocean cool down?
The effect that this 450-1300 AD cooling of the eastern side of the tropical Pacific ocean appears to have had on much of the Americas, not only cuts right through the epoch known as Lamb's Medieval Warm Period but continued into the centuries that followed it well into the 16th Century.
When was the warm epoch?
Lamb was the first to use the term Medieval Warm Epoch. Lamb thought that this epoch was at its maximum between 1000 AD–1300 AD, and that it peaked in the 11th Century.
How thick was the El Nino flood?
These show that the sediment layer created by the 1995 El Nino flood was 10-15 cm thick. The layers for two floods in 500 AD and 1100 AD were each over 100 cm thick. The 1100 AD flood marked the collapse of El Tajin and the end of the period on the Gulf coast known as Classic Veracruz.
What caused the medieval warm period?
It has now become clear to scientists that the Medieval Warm Period occurred during a time which had higher than average solar radiation and less volcanic activity (both resulting in warming).
When did the warm places average out with the cool places?
All in all, when the warm places are averaged out with the cool places, it becomes clear that the overall warmth was likely similar to early to mid 20th century warming. Since that early century warming, temperatures have risen well-beyond those achieved during the Medieval Warm Period across most of the globe.
Why did the Vikings travel further north?
This warming thereby allowed Vikings to travel further north than had been previously possible because of reductions in sea ice and land ice in the Arctic.
Is there a need for a lighter approach to climate science?
I understand your position, Doug. Unfortunately, there seems to be an unmet need for a lighter approach to climate science and global warming. Parts of this website fit the bill, others fall short. Mind you, I love listening in on your arguments and appreciate the intellectual rigor. However, I can tell you, most people have neither the education nor the time to understand climate science at this level and are, therefore, easy prey for the skeptics. Ultimately, of course, you will need to bring us along with you to achieve significant policy change... Is that the goal of this website?
Was the Medieval Warm Period warmer than current conditions?
"The Medieval Warm Period was warmer than current conditions. This means recent warming is not unusual and hence must be natural, not man-made." The argument is also logically invalid, even if the premise were true. Otherwise the following argument of the same form would be correct: 'The Black Death in the middle ages is estimated to have killed more of Europe's population than World War 2. This means that deaths during World War 2 were not unusual, and hence must be due to natural causes, not man-made'
Is the medieval period warmer than today?
Climate Myth... " For now, though, it is enough just to see the Medieval WARM Period shown to be global, and warmer than today.". ( Musings from the Chiefio) One of the most often cited arguments of those skeptical of global warming is that the Medieval Warm Period (800-1400 AD) was as warm as or warmer than today.
Can you use temperature to prove global MWP?
MrOTLChamp, firstly you can't use the temperature at one particular spot, in one particular period, to prove a global MWP - which is why you see a difference between the graph and the paper you mention. As for the Northern Hemisphere being warmer than the Southern Hemisphere, have a look at this NASA GISS graph to see the difference between Northern and Southern Hemisphere temperatures in recent times. I'm not directly comparing between now and then but it shows that there is/can be a difference (without the Earth necessarily tipping over too much), particularly due to the amounts of land and sea surfaces. KR has already given you the evidence for the extra reconstructions produced by others apart from Mann. Finally, can you give any other more representative examples as to why you 'don't have much faith in science lately' ? In the meantime, would you know whether the Geological Society of America (Climate Change statement) receives government funds ? If so, how much do they receive ?
The Medieval Climate Anomaly
Mechanisms Driving The Medieval Warm Period
- The Medieval warm period was by and large a regional event. Its presence or absence reflects a redistribution of heat around the planet, and this suggests drivers other than a global increase in atmospheric greenhouse gases such as carbon dioxide. The most likely cause of the regional changes in temperature was related to a modification of the El N...
Unequal Consequences For People and Environments
- For about 300 years, these new climate conditions changed ecosystems and radically altered human societies. As northern Europe became warmer, agriculture spread and generated food surpluses. At the time, England was warm enough to support vineyards, centralised governments in Europe were becoming stronger, people no longer needed fortifications to protect their once li…
What This Means For The Future
- The fact that some areas of the world actually prospered during the Medieval warm period gives ammunition to the global warming sceptics’ position. But there are two fundamental differences that make the Medieval warm period different from what we are experiencing now. 1. The present-day baseline used for comparison to the temperatures in the Medieval warm period is 1960-199…
Overview
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 c. 950 to c. 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.
North Atlantic
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 1 °C (1.8 °F) cooler approximately 400 years ago, during the LIA, and 1700 years ago and was approximately 1 °C warmer 1000 years ago, during the MWP.
Research
The Medieval Warm Period (MWP) is generally thought to have occurred from c. 950–c. 1250, during the European Middle Ages. 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 c. 1200 and around c. 1600. He proposed, "Evidence has been accumulating in many fields of investigati…
Global climate during the Medieval Warm Period
In 2019, by using an extended proxy data set, 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.
Other regions
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. Sediments in Piermont Marsh of the lower Hudson Valley show a dry M…
See also
• Classic Maya collapse – concurrent with the Medieval Warm Period and marked by decades long droughts
• Cretaceous Thermal Maximum – Period of climatic warming that reached its peak approximately 90 million years ago
• Description of the Medieval Warm Period and Little Ice Age in IPCC reports
Further reading
• Hughes, Malcolm K.; Diaz, Henry F. (1994). "Was there a 'medieval warm period', and if so, where and when?" (PDF). Climatic Change. 26 (2–3): 109–42. Bibcode:1994ClCh...26..109H. doi:10.1007/BF01092410. S2CID 128680153.
• Fagan, Brian (2000). The Little Ice Age: How Climate Made History, 1300–1850. Basic Books. ISBN 978-0-465-02272-4.
External links
• HistoricalClimatology.com, further links, resources, and relevant news, updated 2016
• Climate History Network
• The Little Ice Age and Medieval Warm Period at American Geophysical Union