Climate Discussion Nexus. An intriguing new paper in the Journal of Marine Biology and Aquascape challenges conventional wisdom based on photographic and archaeological indicators of tropical sea levels.
Instead of rising gently for hundreds of years until a 20th-century man-made acceleration, they were similar to the present 850 years ago, then rose instead of falling during the Little Ice Age, up to 50 centimeters in many places by the 1600s, then retreated to their current, relatively stable levels. The Medieval Warm Period. The theory of Anthropogenic Global Warming (AGW) holds that the warming trend since the end of the Little Ice Age (LIA) is unnatural and therefore human caused by way of fossil fuel emissions.
The fossil fuel argument becomes relevant because the end of the LIA coincides with the Industrial Revolution such that the whole of the current warming event has occurred “in the industrial economy” making it useful to describe the current warming as “since pre-industrial times”.Skeptics have argued that natural variability must be considered before the industrial economy is taken to be the cause of the recovery from the LIA because the timing of the glacial melt event in Europe (in particular the Colle Gnifetti) that is generally accepted as the marker between the LIA and the current warming period is controversial as described in related a post [LINK]. Hughes 1994: Hughes, Malcolm K., and Henry F. Diaz. “Was there a ‘Medieval Warm Period’, and if so, where and when?.” Like this: Mann, Hayhoe try to erase the Medieval warm period.
Climate alarmists Michael Mann and Katharine Hayhoe have been caught using dubious, revisionist temperature data in their attempt, as one Climategate email author put it, to “deal a mortal blow” to the extensively documented Medieval Warm Period.
Before climate change became a political issue, it was scientifically well-established that a significant global warming event occurred between approximately 900 AD and 1200 AD. For example, the United Nations Intergovernmental Panel on Climate Change (IPCC) First Assessment Report presented a temperature history and visual graph documenting that the Medieval Warm Period existed and that it brought temperatures at least as warm as today (at pg. 7). Multiple peer-reviewed studies provided additional confirmation of the Medieval Warm Period.
The warming climate of the Medieval Warm Period spurred abundant crop production, fewer extreme droughts and floods, growing human population, and improving living standards. James Taylor James M. A review of temperature reconstructions. Guest essay by Andy May In previous posts (here and here), I’ve compared historical events to the Alley and KobashiGISP2 Central Greenland Temperature reconstructions for the past 4,000 years.
Unfortunately, these two reconstructions are very different. Recently Steve McIntyre has suggested a third reconstruction by Bo Vinther. Vinther’s data can be found here. Unfortunately, Vinther is often significantly different from the other two. All three reconstructions are shown in Figure 1. Figure 1. Loehle: Vindication. Guest Post by Craig Loehle (cloehle -at- ncasi.org) When I published my 2000 year reconstruction (Loehle, C. 2007.
A 2000 Year Global Temperature Reconstruction based on Non-Treering Proxy Data. Energy & Environment 18:1049-1058) and the subsequent correction with better confidence intervals (Loehle, C. and Hu McCulloch. 2008. 18 New Papers Link High Solar Activity To Medieval And Modern Warmth, Low Solar Activity To Little Ice Age Cooling. “It is generally accepted that the climate warms during periods of strong solar activity (e.g., the Medieval Warm Period) and cools during periods of low solar activity (e.g., the Little Ice Age).”
—Lyu et al., 2016. Medieval Warm Period Project. Medieval Warm Period Project Project Overview Study Description and Results Africa Antarctica Asia Australia/New Zealand Europe North America Northern Hemisphere Oceans South America MWP-CWP Quantitative Temperature Differentials MWP-CWP Qualitative Temperature Differentials Interactive Map and Time Domain Plot To view this feature, your computer must be configured to run applets that use Java technology.
List of Scientists Whose Work We Cite. Medieval Warm Period. New Study Shows Medieval Climate Period Was Global, Driven By Natural “Atmospheric-Ocean Cycles”, Not CO2. By Die kalte Sonne For a long time it was said that the Medieval Warm Period was a North Atlantic phenomenon.
This proved to be wrong. On June 15, 2019, a paper by Lüning et al. 2019 on the Medieval Warm Period in Oceania appeared in the journal Environmental Reviews. Here is the short version: The Medieval Climate Anomaly in Oceania Temperatures in Oceania have risen by 0.5-1°C over the past 100 years, resulting e.g. in significant retreat of New Zealand’s glaciers. Medieval Warmth Was GLOBAL…Confirmed By Over 1200 Publications At Google Maps. More than 1200 publications show the Medieval Warm Period (MWP) was global – an embarrassment to global warming alarmists who claimed it was regional Global warming alarmist scientists like claiming that the well documented Medieval Warm Period (MWP) was mostly a regional, North Atlantic phenomenon, and was not global, and so we just move along and stop questioning man-made global warming.
For example, the online Britanica entry on the Medieval Warm Period written by John P. Rafferty writes that it occurred “predominantly in the Northern Hemisphere from Greenland eastward through Europe and parts of Asia.” Britanica does state that the claim of a global extent is highly controversial, though it really isn’t as we are about to see. More than 1200 papers evidence it was global Indeed the claim that it was global is now backed up by a huge body of scientific studies meticulously compiled by Dr.
Body Of Proof: Large Number Of Studies Show Medieval Warm Period “Prominent In Southern Hemisphere” Remember how in the late 1990s/early 2000s the Medieval Warm Period (MWP) was made to disappear, and it was claimed that it was mainly a local, North Atlantic phenomenon.
Unfortunately for those trumpeting this claim, a comprehensive worldwide survey of scientific literature is now showing that the MWP was in fact a global phenomenon, suggesting large-scale natural cycles are what is really driving the climate. . ================================= The Medieval Warm Period – a global phenomenon, unprecedented warming, or unprecedented data manipulation? Originally in German here, with some portions translated to English using the Google translator below.
Google translator is largely imperfect, but to read the Google translation in English go here. If anyone wishes to do a personal translation for the entire article, please leave a note in comments and I will replace it. Of great interest is the global graphic below, which shows that the MWP is a worldwide event, not just limited to portions of the Northern Hemisphere. “ “Who controls the past controls the future: who controls the present controls the past.” – George Orwell, 1984 We live in an age of superlatives.
Naturally, also the reporting on climate change must follow this trend. What is the purpose of all this? Click for an interactive graphic that will expand each graph on mouseover. Documenting the Global Extent of the Medieval Warm Period. By Angus McFarlane Introduction In this article I pose the following questions: Was the Medieval Warm Period (MWP) a global event? Where the MWP temperatures higher than recent times? The reasons for asking these questions are that climate establishment have tried to sideline the MWP as a purely local North Atlantic event. I attempt to answer these questions below.
MWP in Europe and Asia. MWP in Africa and the Middle East. MWP in South America. MWP in Australia and New Zealand. MWP in Antarctica. Medieval Climate Anomaly Now Confirmed In Southern Hemisphere On All Four Continents. By Die kalte Sonne (German text translated in the English by P Gosselin) Image Source: Lüning et al. 2019 For a long time it has been said that the Medieval Warm Period was a purely North Atlantic phenomenon.
This has proved to be wrong. The Hockey Sticks. When the IPCC 'disappeared' the Medieval Warm Period. Erasing The Medieval Warm Period. In 1981, NASA’s James Hansen showed a Medieval Warm Period – based on temperatures in Greenland, California and England. In 1981, NASA’s Global temperature trend is based on temperatures in central England, the tree limit in the White Mountains of California, and oxygen isotope measurements in the Greenland ice (W. Dansgaard of the Geophysical Isotope Laboratory, University of Copenhagen, pers. comm.), with the temperature scale set by the variations in the last 100 yearsChallenge_chapter2.pdf The 1990 IPCC report showed the same thing. ipcc_far_wg_I_chapter_07.pdf Overlaying Hansen’s 1981 graph on the 1990 IPCC graph, it can be seen that they are almost identical.
This research was reported in Nature in 1975. 24 May 1975, Page 12 – Ames Daily Tribune The Medieval Warm Period has been known for over 80 years. January 22, 1934 – NYTimes.com. Rise and Fall of the Modern Warming Spike. The first graph appeared in the IPCC 1990 First Assessment Report (FAR) credited to H.H.Lamb, first director of CRU-UEA. The second graph was featured in 2001 IPCC Third Assessment Report (TAR) the famous hockey stick credited to M.
Mann. A previous post Rise and Fall of CAGW described the process that began with Hansen’s flashy Senate testimony in 1988, later supported by Santer’s flashy paper in 1996. This post traces a second iteration that ensued following Michael Mann’s production of the infamous Climate Hockey Stick graph in 1998. Unscientific hockey sticks and hidden data. These maps and graphs make it clear just how brazenly unscientific the Hockey Stick is.