Was the Medieval Warm Period Global?

  title={Was the Medieval Warm Period Global?},
  author={Wallace S. Broecker},
  pages={1497 - 1499}
  • W. Broecker
  • Published 23 February 2001
  • History, Environmental Science
  • Science
During the Medieval Warm Period (800 to 1200 A.D.), the Vikings colonized Greenland. In his Perspective, Broecker discusses whether this warm period was global or regional in extent. He argues that it is the last in a long series of climate fluctuations in the North Atlantic, that it was likely global, and that the present warming should be attributed in part to such an oscillation, upon which the warming due to greenhouse gases is superimposed. 

Extensive glaciers in northwest North America during Medieval time

The Medieval Warm Period is an interval of purportedly warm climate during the early part of the past millennium. The duration, areal extent, and even existence of the Medieval Warm Period have been

The Medieval Warm Period and the Little Ice Age from a sediment record of Lake Ebinur, northwest China

Ma, L., Wu, J., Yu, H., Zeng, H. & Abuduwaili, J. 2011: The Medieval Warm Period and the Little Ice Age from a sediment record of Lake Ebinur, northwest China. Boreas, Vol. 40, pp. 518–524.

The IPCC on a heterogeneous Medieval Warm Period

In their 2007 report, IPCC working group 1 refers to an increased heterogeneity of climate during medieval times about 1000 years ago. This conclusion would be of relevance, as it implies a contrast

Evidence for a ‘Medieval Warm Period’ in a 1,100 year tree‐ring reconstruction of past austral summer temperatures in New Zealand

The occurrence of the Medieval Warm Period (MWP) in the Southern Hemisphere is uncertain because of the paucity of well‐dated, high‐resolution paleo‐temperature records covering the past 1,000 years.

Climate Change and Cultural Dynamics: A Global Perspective on Mid-Holocene Transitions

The Middle Holocene epoch (8,000 to 3,000 years ago) was a time of dramatic changes in the physical world and in human cultures. Across this span, climatic conditions changed rapidly, with cooling in

A late medieval warm period in the Southern Ocean as a delayed response to external forcing?

On the basis of long simulations performed with a three‐dimensional climate model, we propose an interhemispheric climate lag mechanism, involving the long‐term memory of deepwater masses. Warm

High-Frequency Holocene Glacier Fluctuations in New Zealand Differ from the Northern Signature

A high-resolution 10Be chronology of glacier fluctuations in New Zealand’s Southern Alps over the past 7000 years, including at least five events during the last millennium is presented, suggesting that atmospheric circulation changes in the southwest Pacific were one important factor in forcing high-frequency Holocene glacier fluctuations.

Termination of the Medieval Warm Period: Linking sub-polar and tropical N Atlantic circulation changes to ENSO

PAGES News • Vol.17 • No 2 • June 2009 Sc ie nc e H ig hl ig ht s: P ol ar P al eo sc ie nc e A dd en du m Termination of the Medieval Warm Period: Linking subpolar and tropical N Atlantic



Little Ice Age

The term Little Ice Age was originally coined by F Matthesin 1939 to describe the most recent 4000 year climaticinterval (the Late Holocene) associated with a particularlydramatic series of mountain


Hughen et al. [1998] have documented that during the first 200 years of Younger Dryas time the 14C content of atmospheric CO2 increased by ∼50‰ and that during the remainder of this

Late Quaternary temperature changes seen in world‐wide continental heat flow measurements

Analysis of more than six thousand continental heat flow measurements as a function of depth has yielded a reconstruction of a global average ground surface temperature history over the last 20,000

Synchronous climate changes in antarctica and the north atlantic

  • SteigBrook Clow
  • Environmental Science, Geography
  • 1998
It is shown here that two of the most prominent North Atlantic events-the rapid warming that marks the end of the last glacial period and the Bolling/Allerod-Younger Dryas oscillation-are also recorded in an ice core from Taylor Dome, in the western Ross Sea sector of Antarctica.

Extreme and persistent drought in California and Patagonia during mediaeval time

STUDIES from sites around the world1–5 have provided evidence for anomalous climate conditions persisting for several hundred years before about AD 1300. Early workers emphasized the temperature

Northern hemisphere temperatures during the past millennium: Inferences, uncertainties, and limitations

Building on recent studies, we attempt hemispheric temperature reconstructions with proxy data networks for the past millennium. We focus not just on the reconstructions, but the uncertainties

Swiss glacier recession since the Little Ice Age: Reconciliation with climate records

Since the culmination of the Little Ice Age, Alpine glaciers have been in a state of general retreat. The present study, focusing on the Swiss Alps between 1850 and 1973, seeks to relate the

A possible 20th-century slowdown of southern ocean deep water formation

Physical oceanographic and geochemical studies in the Southern Ocean suggest that no more than 5 x 10(6) cubic meters per second of ventilated deep water is currently being produced, which conflicts with conclusions based on the distributions of the carbon-14/carbon ratio and a quasi-conservative property in the deep sea.

INTCAL98 radiocarbon age calibration, 24,000-0 cal BP.

The focus of this paper is the conversion of radiocarbon ages to calibrated (cal) ages for the interval 24,000–0 cal BP (Before Present, 0 cal BP = AD 1950), based upon a sample set of