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Paleoclimate

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In the last 10,000 years, was climate fairly stable until the advent of increased carbon dioxide in the atmosphere post industrialization? Or was there considerable variability in climate with temperatures higher than those measured today?

There is considerable evidence for the Medieval Warm Period and other periods of warmer temperatures. An argument can be made that our current warming is a continuation of the warming that began at the end of the Little Ice Age. Check the resources in this section for more... Inconvenient: new treeline paper suggests temperatures were warmer 9000 years ago. It’s Here: A 1900-2010 Instrumental Global Temperature Record That Closely Aligns With Paleo-Proxy Data. A global-scale instrumental temperature record that has not been contaminated by (a) artificial urban heat (asphalt, machines, industrial waste heat, etc.), (b) ocean-air affected biases (detailed herein), or (c) artificial adjustments to past data that uniformly serve to cool the past and warm the present . . . is now available.

Composed of 450 instrumental records from temperature stations sheltered from ocean-air/urbanization/adjustment biases throughout the world, a new 20th/21st century global temperature record introduced previously here very closely aligns with paleoclimate evidence from tree rings, ice cores, fossil pollen and other temperature proxies. The Alignment Of Paleoclimate Proxy Data & Instrumental Records In 2016, Dr. Image Source: Xing et al., 2016 (MDVM Reconstructed NH Temperature) Christiansen and Lungqvist (2012) utilize proxies from 91 locations across the extra-tropical Northern Hemisphere to reveal no net warming since the 1940s. Image Source: Stoffel et al., 2015.

81 Graphs From 62 New (2018) Papers Invalidate Claims Of Unprecedented Global-Scale Modern Warming. By Kenneth Richard on 10. May 2018 During 2017, there were 150 graphs from 122 scientific papers published in peer-reviewed journals indicating modern temperatures are not unprecedented, unusual, or hockey-stick-shaped — nor do they fall outside the range of natural variability. We are a little over 4 months into the new publication year and already 81 graphs from 62 scientific papers undermine claims that modern era warming is climatically unusual. Zheng et al., 2018 “In this study we present a detailed GDGT data set covering the last 13,000 years from a peat sequence in the Changbai Mountain in NE China.

The brGDGT-based temperature reconstruction from Gushantun peat indicates that mean annual air temperatures in NE China during the early Holocene were 5–7°C higher than today. Furthermore, MAAT records from the Chinese Loess Plateau also suggested temperature maxima 7–9°C higher than modern during the early Holocene (Peterse et al., 2014; Gao et al., 2012; Jia et al., 2013). Mikis, 2018.

Medieval Warm Period (MWP)

Little Ice Age (LIA) and Other Mini-Ice-Ages. The Roman Warm Period. Holocene Thermal Optimum. The Hockey Sticks. 200 Non-Hockey Stick Graphs Published Since 2017 Invalidate Claims Of Unprecedented, Global-Scale Warming. By Kenneth Richard on 22. March 2018 46 New (2018) Non-Warming Graphs Affirm Nothing Climatically Unusual Is Happening Image Source: Lansner and Pepke Pederson, 2018 During 2017, there were 150 graphs from 122 scientific papers published in peer-reviewed journals indicating modern temperatures are not unprecedented, unusual, or hockey-stick-shaped — nor do they fall outside the range of natural variability. We are less than 3 months into the new publication year. Already 46 new graphs from 40+ scientific papers undermine claims that modern era warming — or, in some regions, modern cooling — is climatically unusual. 2018 and 2017 Non-Hockey Stick Graphs (~200) Maley et al., 2018 Polovodova Asteman et al., 2018 Wündsch et al., 2018 McGowan et al., 2018 “Our reconstructed Tmax [temperature maximum] for these warmer conditions peaks around 1390 CE at + 0.8 °C above the 1961–90 mean, similar to the peak Tmax during the RWP [Roman Warm Period].

Wu et al., 2018 Hanna et al., 2018 Li et al., 2018 Eck, 2018. Climate and Human Civilization over the last 18,000 years. Paleoclimate Page | Watts Up With That? 472 Years – CET Extended Graph – Tony Brown – Graph Background Tony Brown – Climate Etc. – Click the pic to view at source 600 Years Arctic Temperature – Overpeck et al. 1997 NOAA NCDC – Click the pic to view at source 1,100 Years – Ljungqvist et al CO2Science.Org – Click the pic to view at source 1,100 Years Ljungqvist et al JoNova.com – Click the pic to view at source 1,100 Years Kirby Kirkby 2007 Harvard – Kirby – Click the pic to view at source 1,100 Years – Lamb – IPCC Assessment Report 1 – Graph Background JoNova – IPCC AR1 – Click the pic to view at source 1,205 Years – M.L.

BioCab.org – Click the pic to view at source 2,000 Years – “Loehle and McCulloch 2008 Graph Background Craig Loehle, Ph.D. and J. 2,000 Years – J. J. 2,000 Years Christiansen 2,100 Years – Law Dome O18 Climate Audit – Law Dome – Click the pic to view at source 2,500 Years – GISP2 – Alley, 2000 Photobucket.com – Click the pic to view at source 3,000 Years – GISP2 – Alley, 2000, Moberg, Keigwin & HadCRUT3 10,000 Years – Vostok E.

Lindzen, Soon and Spencer debunked? By Andy May On Bret Stephens facebook page, I complimented Mr. Stephens on what I thought was a very good column. I also noted that the eminent climate scientist Dr. Richard Lindzen had said similar things. “Few “skeptics” have been debunked as much as Lindzen and Spencer.” Link to comment here. If you follow the link you will see it is followed with a google search for “Lindzen debunked.” The first reference in my search led to desmogblog, here. Their arguments appear to be as vacuous as their resumes. Figure 1 (source here) Below we see Dr. Figure 2 (source here) All of this “hottest year on record” nonsense is absurd, we are talking about very small changes in the average temperature.

Figure 3 (Data sources here and here) There is a secular warming trend that has persisted since the end of the Little Ice Age in the 19th century. Figure 4, “Anthropogenic Climate Change” (source here) Then, as now, the public chose to blame people for climate change without proof. Figure 6 (source) A Holocene Temperature Reconstruction Part 1: the Antarctic. By Andy May The only recent attempt at a global Holocene temperature reconstruction available today is the one by Marcott, et al. (2013), the paper abstract can be viewed here. His reconstruction is shown in figure 1. Figure 1 The Y axis is a reconstructed global temperature anomaly from the 1961-1990 mean. The reconstruction in figure 1 goes from the present (1950) on the left to nearly the beginning of the Holocene about 11,700 years ago on the right. The reconstruction shows an abrupt warming in the last 100 years (see the left side of figure 1). “We showed that no temperature variability is preserved in our reconstruction at cycles shorter than 300 years, 50% is preserved at 1000-year time scales, and nearly all is preserved at 2000-year periods and longer.

The problem is that 300 years is a very long time. This is a new look at Marcott’s proxies. Proxy selection The proxies were examined considering the criticism of Marcott’s analysis by Javier, McIntyre and Foster. Figure 2 Table 1. A Holocene Temperature Reconstruction Part 2: More reconstructions. By Andy May In the last post (see here) we introduced a new Holocene temperature reconstruction for Antarctica using some of the Marcott, et al. (2013) proxies. In this post, we will present two more reconstructions, one for the Southern Hemisphere mid-latitudes (60°S to 30°S) and another for the tropics (30°S to 30°N).

The next post will present the Northern Hemisphere mid-latitudes (30°N to 60°N) and the Arctic (60°N to the North Pole). As we did for the Antarctic, we will examine each proxy and reject any that have an average time step greater than 130 years or if it does not cover at least part of the Little Ice Age (LIA) and the Holocene Climatic Optimum (HCO). We are looking for coverage from 9000 BP to 500 BP or very close to these values. Southern Hemisphere mid-latitudes Our reconstruction for this region is shown in figure 1. Figure 1 This reconstruction has a more defined HCO than we saw in the Antarctic and it is placed between 8000 BP and 5000 BP. Figure 2 Figure 3 Figure 4. A Holocene Temperature Reconstruction Part 3: The NH and Arctic. By Andy May In the last post (see here) we reexamined the Marcott, et al. (2013) proxies for the Southern Hemisphere mid-latitudes and the tropics.

In this post, we will present two more reconstructions using their proxies, these are for the Northern Hemisphere mid-latitudes (30°N to 60°N) and for the Arctic region (60°N to 90°N). These two regions contain over half of the proxies used in this study. The next post will present a global area-weighted composite temperature reconstruction. As we did in the previous two posts, we will examine each proxy and reject any that have an average time step greater than 130 years or if it does not cover at least part of the Little Ice Age (LIA) and the Holocene Climatic Optimum (HCO). We are looking for coverage from 9000 BP to 500 BP or very close to these values. Northern hemisphere mid-latitudes There are 10 proxies that meet our basic criteria for the Northern Hemisphere reconstruction, although two of them are combined into one record. Figure 2. A Holocene Temperature Reconstruction Part 4: The global reconstruction.

By Andy May In previous posts (here, here and here), we have shown reconstructions for the Antarctic, Southern Hemisphere mid-latitudes, the tropics, the Northern Hemisphere mid-latitudes, and the Arctic. Here we combine them into a simple global temperature reconstruction. The five regional reconstructions are shown in figure 1. The R code to map the proxy locations, the references and metadata for the proxies, and the global reconstruction spreadsheet can be downloaded here.

For a description of the proxies and methods used, see part 1, here. Figure 1A, all proxies except TN057-17 on the Antarctic Polar Front Figure 1B, the proxies used for the reconstructions It is interesting that the Northern Hemisphere is the odd reconstruction. Figure 2 (Source: Javier, see his post for a detailed explanation of the figure.) The Southern Hemisphere is also a bit anomalous, with a dip in the period of the HCO, corresponding with a dip in winter insolation in the Southern Hemisphere.

Table 1 Conclusions. Global versus Greenland Holocene Temperatures. By Andy May Last week, I posted a global temperature reconstruction based mostly on Marcott, et al. 2013 proxies. The post can be found here. In the comments on the Wattsupwiththat post there was considerable discussion about the difference between my Northern Hemisphere mid-latitude (30°N to 60°N) and the GISP2 Richard Alley central Greenland temperature reconstruction (see here for the reference and data).

See the comments by Dr. Don Easterbrook and Joachim Seifert (weltklima) here and here, as well as their earlier comments. Richard Alley’s (Richard Alley, 2000) central Greenland reconstruction has become the de facto standard reconstruction and is displayed often in papers and posts. Figure 1 Alley’s reconstruction is based upon trapped air in ice cores taken from central Greenland and his proxies are calibrated to air temperatures on land.

Figure 2 Figure 3 Vinther’s record shows a more prominent HCO than ours, more detail and a deeper LIA. Figure 4 Figure 5 Figure 7 (Source CDIAC) A never before western published paleoclimate study from China suggests warmer temperatures in the past. People send me stuff. Today in my inbox, WUWT regular Michael Palmer sends this note: My wife Shenhui Lang found and translated an interesting article from 1973 that attempts the reconstruction of a climate record for China through several millennia (see attached). The author is long dead (he died in 1974), and “China Daily” is now the name of an English language newspaper established only in 1981. I think it would be very difficult to even locate anyone holding the rights to the original, and very unlikely for anyone to take [copyright] issue with the publication of the English translation.

The paper is interesting in that it shows a correlation between height of the Norwegian snow line and temperature in China for the last 5000 years. A Preliminary Study on the Climatic Fluctuation during the last 5000 years in China Zhu Kezhen Published in China Daily, June 19th, 1973 / translated by Shenhui Lang, PhD In the monsoon area of East Asia, the annual rainfall often varies greatly. 1. 2. 3. 4. The Proliferation Of Non-Global Warming Graphs In Science Journals Continues Unabated In 2018.

During 2017, there were 150 graphs from 122 scientific papers published in peer-reviewed journals that indicated modern temperatures are not unprecedented, unusual, or hockey-stick-shaped — nor do they fall outside the range of natural variability. Less than 3 weeks into the new publication year, the explosion of non-alarming depictions of modern climate change continues. Blarquez et al., 2018 Magyari et al., 2018 …its climatic tolerance limits were used to infer July mean temperatures exceeding modern values by 2.8°C at this time [8200-6700 cal yr BP] (Magyari et al., 2012).

White et al., 2018 Our data, together with published work, indicate both a long-term trend in ENSO strength due to June insolation [solar] forcing and high-amplitude decadalcentennial fluctuations; both behaviors are shown in models. Song et al., 2018 Huang et al., 2018 Perner et al., 2018 Maley et al., 2018 Polovodova Asteman et al., 2018 Papadomanolaki et al., 2018 (Baltic Sea) Yi, 2018 Bereiter et al., 2018 (press release) 150 NON-Global Warming Graphs From 2017 Pummel Claims Of Unusual Modern Warmth.

By Kenneth Richard on 1. January 2018 …in 122 (2017) scientific papers Image Source: Loisel et al., 201 2017: 150 Graphs, 122 Scientific Papers In the last 12 months, 150 graphs from 122 peer-reviewed scientific papers have been published that undermine the popularized conception of a slowly cooling Earth temperature history followed by a dramatic hockey-stick-shaped uptick, or an especially unusual global-scale warming during modern times. Yes, some regions of the Earth have been warming in recent decades or at some point in the last 100 years. Some regions have been cooling for decades at a time. And many regions have shown no significant net changes or trends in either direction relative to the last few hundred to thousands of years.

Succinctly, then, scientists publishing in peer-reviewed journals have increasingly affirmed that there is nothing historically unprecedented or remarkable about today’s climate when viewed in the context of long-term natural variability. 1. 2. 3. 4. 5. 6. 7. 80 Graphs From 58 New (2017) Papers Invalidate Claims Of Unprecedented Global-Scale Modern Warming.

By Kenneth Richard on 29. May 2017 “[W]hen it comes to disentangling natural variability from anthropogenically affected variability the vast majority of the instrumental record may be biased.” — Büntgen et al., 2017 Yes, some regions of the Earth have been warming in recent decades or at some point in the last 100 years. Some regions have been cooling for decades at a time. And many regions have shown no significant net changes or trends in either direction relative to the last few hundred to thousands of years. Succinctly, then, scientists publishing in peer-reviewed journals have increasingly affirmed that there is nothing historically unprecedented or remarkable about today’s climate when viewed in the context of long-term natural variability. Büntgen et al., 2017 “Spanning the period 1186-2014 CE, the new reconstruction reveals overall warmer conditions around 1200 and 1400, and again after ~1850.

Parker and Ollier, 2017 Gennaretti et al., 2017 Abrantes et al., 2017 Werner et al., 2017. Significant finding: Study shows why Europe’s climate varied over the past 3000 years. From CARDIFF UNIVERSITY and the “motion from the ocean makes or breaks English vineyards” department. Ocean floor mud reveals secrets of past European climateSamples of sediment taken from the ocean floor of the North Atlantic Ocean have given researchers an unprecedented insight into the reasons why Europe’s climate has changed over the past 3000 years.

In this 1677 painting by Abraham Hondius, ‘The Frozen Thames, looking Eastwards towards Old London Bridge’, people are shown enjoying themselves on the ice during a “frost fair”. From the warmer climates of Roman times when vineyards flourished in England and Wales to the colder conditions that led to crop failure, famine and pandemics in early medieval times, Europe’s climate has varied over the past three millennia. For the first time, researchers have been able to pinpoint why this occurs, and the answer lies far out at sea in the North Atlantic Ocean. Sediment core location and regional ocean circulation. Abstract Data availability.

485 Scientific Papers Published In 2017 Support A Skeptical Position On Climate Alarm. The Hockey Stick Collapses: 60 New (2016) Scientific Papers Affirm Today’s Warming Isn’t Global, Unprecedented, Or Remarkable. Deconstruction Of The Critical YouTube Response To Our 400+ ‘Skeptical’ Papers Compilation.

Climate and Human Civilization over the last 18,000 years, updated | Andy May Petrophysicist. Climate and Human Civilization for the Past 4,000 Years | Watts Up With That? A beneficial climate change hypothesis | Climate Etc. Effect of Atmospheric CO2 Concentrations on Early Human Societies | Watts Up With That? Nature Unbound III – Holocene climate variability (Part B) | Climate Etc. History Is Clear: Humans Prospered In Climates That Were Warmer Than Today’s…Died In Cooler Ones.

Climate Profoundly Impacted Development Of Civilization…Cool Periods Brought On Plagues/Death. Distinguishing Between ‘Safe’ or ‘Dangerous’ Warming Is Easy: ‘Dangerous’ Warming Is Red. New Paper Asserts ‘Biased’ Climate Models Underestimate Natural Variability And The Warmth Of The Past. 50 Inverted Hockey Sticks – Scientists Find Earth Cools As CO2 Rises.

‘Hide The Decline’ Unveiled: 50 Non-Hockey Stick Graphs Quash Modern ‘Global’ Warming Claims. Hockey Stick Was Refuted Before Its Fabrication – Study Ignored – IPCC And Mann Took World On 10-Year Joyride. 8 New Papers Reveal ‘Natural’ Global Warming Reaches Amplitudes Of 10°C In Just 50 Years With No CO2 Influence. Inconvenient: New paper finds the last interglacial was warmer than today – not simulated by climate models | Watts Up With That? Global Temperature Trends From 2500 B.C. To 2040 A.D. - Principia Scientific International.

2 More New Papers Affirm There Is More Arctic Ice Coverage Today Than During The 1400s. Inconvenient new study: Canadian Arctic had significantly warmer summers a few thousand years ago | Watts Up With That? Climate and People in the Prehistoric Arctic. New paleo reconstruction shows warmer periods in Alaska over the past 3000 years | Watts Up With That? Ice Patch Archaeology in Global Perspective: Archaeological Discoveries from Alpine Ice Patches Worldwide and Their Relationship with Paleoclimates. Archaeological Finds in Retreating Swiss Glacier « Climate Audit. Receding Swiss glaciers incoveniently reveal 4000 year old forests – and make it clear that glacier retreat is nothing new | Watts Up With That? Yet another paper demonstrates warmer temperatures 1000 years ago and even 2000 years ago. | Watts Up With That? “We Live In The Coldest Period Of The Last 10.000 Years" | NOT A LOT OF PEOPLE KNOW THAT.

CO2: Ice Cores vs. Plant Stomata | Watts Up With That? New Study: Two Thousand Years of Northern European Summer Temperatures Show a Downward Trend | Watts Up With That? The oldest ice core – Finding a 1.5 million-year record of Earth’s climate | Watts Up With That? Paleo-clamatology | Watts Up With That? A review of temperature reconstructions | Watts Up With That?

HH Lamb–“Climate: Present, Past & Future–Vol 2”–In Review–Part I | NOT A LOT OF PEOPLE KNOW THAT. Parts of Asia Were Warmer During the Holocene Than They Are Now. Climate Study: Scotland Warmer in 1300s, 1500s, and 1730s - Principia Scientific International. A 2000-Year SST History of the Northeastern Arabian Sea. Easterbrook on the magnitude of Greenland GISP2 ice core data | Watts Up With That? Four Centuries of Summer Temperatures in Coastal Northern Japan. Four Centuries of Spring Temperatures in Nepal. A Thousand-Year Drought History of China's Qilian Mountains. An 850-Year Hydroclimatic History of Northwestern China. 1200 Years of Historic Streamflow in the Eastern Great Basin of North America. Modeling 12 Centuries of Northern Hemispheric Hydroclimate. Comparing the Kobashi and Alley Central Greenland Temperature Reconstructions | Andy May Petrophysicist. A Review of Temperature Reconstructions | Andy May Petrophysicist.

Another New Paper Reveals No Discernible Human Influence On Global Ocean Temperatures, Climate. Warmest in a Millll-yun Years « Climate Audit.