Warm periods in the 20th century are not unprecedented during the last 2,000 years

Posted: August 9, 2017 by oldbrew in climate, research
Tags: ,

Credit: wisegeek.com

Long-term natural climate variation just won’t go away, as this report at phys.org shows.

A great deal of evidence relating to ancient climate variation is preserved in proxy data such as tree rings, lake sediments, ice cores, stalagmites, corals and historical documents, and these sources have great significance in evaluating 20th century climate warming in the context of the last two millennia.

Prof. Quansheng Ge and his group from the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, collected a large number of proxies and reconstructed a 2000-year temperature series in China with a 10-year resolution, enabling them to quantitatively reveal the characteristics of temperature change in China over a common era.

“We found four warm epochs,” says Prof. Ge, “which were AD 1 to AD 200, AD 550 to AD 760, AD 950 to AD 1300, and the 20th century. Cold periods occurred between AD 210 and AD 350, AD 420 and AD 530, AD 780 and AD 940, and AD 1320 and AD 1900. The temperature amplitude between the warmest and coldest decades was 1.3°C.”

Prof. Ge’s team found that the most rapid warming in China occurred over AD 1870-2000, at a rate of 0.56 ± 0.42°C (100 yr); however, temperatures recorded in the 20th century may not be unprecedented in the last 2000 years, as reconstruction showed records for the period from 981 to 1100, and again from 1201 to 1270, were comparable to those of the present warm period, but with an uncertainty of ±0.28°C to ±0.42°C at the 95 percent confidence interval.

Since 1000 CE—the period covering the Medieval Climate Anomaly, Little Ice Age, and the present warm period—temperature variations over China have typically been in phase with those of the Northern Hemisphere as a whole.

Continued here.

  1. Graeme No.3 says:

    The only thing out-of-phase is the Chinese governments contempt for the gullible politicians in the West and their determination to forward Chinese prosperity. How different from the UK, Germany, France, Denmark etc. where examining the real evidence is regarded as unnecessary.

  2. George Let says:

    We need to have the White House have other scientists like Will Happer, Patrick Moore, Tim Ball, John Christy, Roy Spencer present the other side of the climate story from that draft government report on climate change.

  3. oldbrew says:

    ‘records for the period from 981 to 1100, and again from 1201 to 1270, were comparable to those of the present warm period’

    So today’s climate is by no means ‘unprecedented’ as claimed by serial exaggerators.
    – – –
    ‘A cooling trend at the centennial scale and social economic decline run hand-in-hand.’

    Climate alarmists should be careful what they wish for.

  4. thefordprefect says:

    However as we “know” all reconstructed temperatures are FRAUDs and unreliable so how can we trust this one?

  5. oldbrew says:

    Date: 08/08/17 Daily Caller

    Eastern China is in the midst of a two decade-long cooling trend, according to a new study, which labeled it a continuation of the “warming hiatus” that global temperatures experienced in the early 21st Century.
    . . .
    “During the past two decades since 1997, eastern China has experienced a warming hiatus punctuated by significant cooling in minimum temperature (Tmin), particularly during early-mid winter,” researchers with the China Meteorological Administration wrote in their July study.


  6. Jaime Jessop says:

    The evidence for natural warming and cooling periods throughout the Holocene, similar in magnitude and rapidity to the current warming which ended the LIA and which has continued to the present, is beginning to become ‘overwhelming’ – a term much favoured by warmists to describe the evidence for anthropogenic climate change. I personally find the evidence for attributing the recent temperature excursion primarily to natural causes rather more compelling than to fossil fuel emissions.

    “Prof. Ge’s team found that the most rapid warming in China occurred over AD 1870-2000.” I can see AGW fanatics immediately leaping upon this as ‘evidence’ that the current warming is unprecedented and man-made, but this should be viewed in the context of the fact that the Maunder Minimum (1645-1715), followed by the Dalton Minimum (1790-1830) was an exceptionally cold period occurring just before the ascent into a 20th century Grand Solar maximum, representing the most intense solar activity for 8000 years. The starting point for this ascent was the super El Nino of 1876-78, occurring just as SC11 died and SC12 began, when AMO peaked sharply and massively just before it began a decadal decline. 1876-78 represented a “climate shift” probably even more significant than the Pacific climate shift of 1976-77 which occurred exactly one hundred years later. 1876-78 was when the Little Ice Age ended suddenly, abruptly and the modern warm period began. But ‘scientists’ insist it was the beginning of the Industrial Revolution which was responsible for kick-starting global warming back then, with the advent of almost imperceptible amounts of CO2 entering the atmosphere via the burning of fossil fuels. Who to believe?

  7. oldbrew says:

    Washington Post Jan. 11, 1970

    Get a good grip on your long johns, cold weather haters–the worst may be yet to come. That’s the long-long-range weather forecast being given out by “climatologists.” the people who study very long-term world weather trends.

    – – –
    And for your next scare story…

    Dutch news item 2017: Fifty times more deaths by weather

    According to the [EC] study, there will be about 152,000 deaths by weather-related phenomena per year between 2071 and 2100, mainly caused by climate change.

    According to the paper, 99% of those deaths will be heat-related fatalities.


    NB the actual study says ‘could be’ not ‘will be’.

  8. Bitter&twisted says:

    The Flawed Prefect says “all climate reconstructions are frauds”
    Not all, just those that use Mannian statistics and post-collection “selection” to provide the “correct” answer.
    However, even if the data is analysed properly you still lose high frequency variation, which then reduces the amplitude of both high and low temperatures.

  9. oldbrew says:

    The uncertainty monster…

    The climate Uncertainty Monster is maturing, and he is demanding that we pay attention.


  10. E.M.Smith says:

    Gee… Just AFTER The POTUS Trump says no money from the USA for your UN Paris scam, the Chinese start producing valid science showing it is normal climate….

    I think we can generalize from this:

    “Money causes global warming”.

    So clearly the cure is to shut off the money…