Another New Paper Traces Variations In Temperatures, Precipitation To Variations In Solar Activity

Scientists Ascribe Climate Changes

To Solar Forcing – No CO2 Attribution

In recent months, there have been dozens of papers published in the scientific literature ascribing variations in temperature and precipitation (climate) to corresponding variations in solar forcing.

Another new paper, Zhang et al., 2017, has just been published online.  The nine scientists contributing to the research place special emphasis on the relationship between solar activity and climate for the Qinghai-Tibetan Plateau region of Central Asia for the last 10,000-12,000 years.

The authors link high and low solar activity to correspondingly high and low temperatures and precipitation.  Undulating millennial- and centennial-scale temperatures are found to vary by about 2.5°C throughout the Holocene.   No mention is made of carbon dioxide as an influential factor affecting climate change.

Although the instrumental record for the region documents an abrupt warming in recent decades (which aligns with the Modern Grand Maximum), the proxy evidence from subfossil chironomids used to reconstruct temperature does not show a significant or unusual regional warming trend during the last century.

Holocene high-res. quantitative summer temp. reconstruction …

southeast margin of the Qinghai-Tibetan Plateau [Central Asia]

Zhang et al., 2017

1.    The record suggests the summer temperature varies by ~2.5 °C across the entire period. A generally warmer period occurred between c.8500 and c.6000 cal yr BP and a cooling trend was initiated from c.5500 cal yr BP. The overall pattern broadly matches the summer insolation at 30N and the Asian Summer Monsoon records from the surrounding regions suggesting that summer temperatures from the southeast margin of the QTP [Qinghai-Tibetan Plateau] respond to insolation forcing and monsoon driven variability on a multi-millennial time scale. Modifications of this overall trend are observed on the finer temporal resolution and we suggest that solar activity could be an important mechanism driving the centennial-scale variability. It may have a strengthened effect in the late Holocene when the monsoon influence weakened.

2.    We highlight that solar activity likely plays an enhanced role in changes of summer temperatures because of the high elevation of the QTP when the monsoon is weaker. The results also indicate that summer temperature variability at the QTP responds rapidly to solar irradiance changes in the late Holocene.

3.  The temperature drop may be also due to a decline in the solar activity related to the Hallstatt cycle, with solar minima centered at approximately 8200, 5500, 2500 and 500 cal yr BP (Steinhilber et al., 2012).

4.   All three records broadly follow the decreasing trend of summer insolation at 30 N (Berger and Loutre, 1991) and this pattern is widely recorded across southern and eastern Asia including from Dongge and Qunf Caves (Dykoski et al., 2005; Fleitmann et al., 2007). The trend is marked by a broad shift to lower average summer temperature values from ~5500 cal yr BP in the lake records, suggesting that long-term summer temperature and precipitation changes in southwestern China respond to changes in insolation forcing (Gray et al., 2010).

5.   The delayed response of regional climate to orbital forcing in the early Holocene may be linked to the temperature variability predominantly being driven by centennial scale solar irradiance fluctuations during this period (Fleitmann et al., 2003; Wang et al., 2005). In addition, the existence of remnant ice sheets in the Northern Hemisphere high latitudes in the early Holocene could have also caused the delay of the attainment of a temperature optimum in southwestern China in response to the solar insolation maximum (Xiao et al., 2009; Wen et al., 2010).

6.   The chironomid record from Tiancai Lake shows a 2.2° C summer warming just after ~2500 cal yr BP and the alkenone-based record from Qinghai Lake also shows a warming at this time interval. The warm period persisted for nearly 1000 years until ~1600 cal yr BP. This temporal coherence suggests a regional climate response and indicates that secondary forcing mechanisms can modify the insolation driven system. This warm period is possibly related to the rapid and overall rise of solar activity (Steinhilber et al., 2012).

7.   [T]hese observations may reflect the variability of the Indian Summer Monsoon as a result of the enhanced solar activity influence. It is in line with evidence suggested in a few studies (Lihua et al., 2007; Thamban et al., 2007; Hiremath et al., 2015) from the Indian Summer Monsoon (e.g. Bay of Bengal) influenced area. In summary, the solar irradiance fluctuation is inferred to affect the summer air temperatures at the QTP either by directly raising lake water temperatures at the high altitude under a weakened summer monsoon condition or alternatively, it could also result in variations of the Indian Summer Monsoon activity at decadal to centennial scale in the late Holocene.

8.   In general, the pattern of millennial summer temperature changes is driven by the summer insolation-forced intensity of Asian summer monsoons during the Holocene. Variations from this general pattern were evident during the late Holocene and may be related to a shift in solar activity (e.g. from ~2500 to 1600 cal yr BP).

46 responses to “Another New Paper Traces Variations In Temperatures, Precipitation To Variations In Solar Activity”

  1. AndyG55

    Amazing that all that solar activity had a large warming effect during the Holocene Optimum..

    … but the slight warming during the 2nd half of last century, when there was a Grand Solar Maximum, was totally due to CO2, which has no provable warming ability on anything.

    Wonders will never cease. 😉

    1. Craig T

      Look at the paper again. Solar activity caused minor variations during the Holocene while seasonal insolation caused by orbital procession drove the overall trend.

      And global changes caused by the Grand Solar Maximum, Maunder Minimum and Medieval Maximum? I took the red and blue colors that Kennith added to the solar activity graph and added them to all the data shown in Figure 6.

      You’ll see that the temperature of the Tibetan lakes fell during the Medieval Maximum, rose during the Little Ice Age and fell during the Grand Solar Maximum. This supports the idea that the LIA and Medieval Warm Period were regional events. Even in the GGISP2 ice cores temperatures fell during the last half of the Medieval Maximum despite solar activity being just as high as the first half.

  2. tom0mason

    OT but…

    Chinese researchers have been looking at the urban heat island effect and have some very interesting results.

    Yearly temperature rise at Beijing and Wuhan stations related to the nearby rural temperature change is estimated to be 0.26°C/10 yr. and 0.20°C/10 yr. respectively for 1961∼2000, and 0.47°C/10 yr. and 0.34°C/10 yr. respectively for 1981∼2000. More rapid urban warming is underdone for the late period of 1981∼2000, with Beijing Station being even more remarkable than Wuhan Station. In comparison to 1961∼2000, urban warming during 1981∼2000 increases by 81% for Beijing Station and 70% for Wuhan Station. Therefore, larger impact of urbanization occurs at the two city stations during the last 20 years when urbanization and economic growth of China are unprecedented in history.

    I wonder how these UHI effects impacts on US, European, and Australian stations and the reliability of their results.

    1. Pethefin

      Could you provide a link to this paper?
      Finally the UHI is being looked at thoroughly but the same should be done in arctic regions also, since the effect might be very extensive due to thermal leaks from the buildings etc.

    2. tom0mason
  3. Craig T

    A better title would be “Scientists ascribe Holocene climate changes to orbital forcing – modified by solar forcing – not driven by CO2.”

    From the paper’s conclusions: “Our record suggests that the millennial summer temperature variability at Tiancai Lake is driven by the insolation-forced Asian summer monsoon intensity and the latitudinal shift of the ITCZ. The overall pattern is likely modified by regional climate drivers and solar irradiance.”

    The paper found changes in the summer insolation (incoming solar radiation) to be the primary cause of changes in the Qinghai-Tibetan Plateau climate during the Holocene. Changes in seasonal insolation is caused by precession, one of the Milankovitch Cycles. Precession has a cycle of 23,000 years, so 12,000 years is almost half of the cycle. Figure 6b from Zhang 2017 shows precession caused a 30 W/m2 drop in summer insolation during the Holocene.

    Figure 6 shows lake temperatures in the QTP follow the trend of the change in summer insolation. I added the blue bars from figure 5 showing Hallstatt cycle solar minima around 8200, 5500, 2500 and 500 cal yr BP. Those are the periods the paper thought dips in solar activity lowered QTP temperatures somewhat. They were minor deviations in the overall trend. (Hallstatt cycles last 2100-2500 years. If the LIA was caused by the Hallstatt minima 500 years ago, don’t look for the next little ice age until after the year 3500.)
    The subheader for the post would be “Paper supports consensus.”Climate textbooks teach about the impact of Milankovitch Cycles on climate. http://w No scientist ever claimed that CO2 was the driving factor in all climate change.

    1. AndyG55

      The Holocene optimum has been shown to be world wide.

      Precession.. nope!

      6b from Zhang?? the Earth was not closer, precession is wobble of the Earth’s axis, not change in distance from sun.

      I think we can dismiss anything Zhang says , as he seems to have a somewhat tenuous grip on even what he preaches.

      1. Craig T

        Andy, before you dismiss the entire Zhang paper go back and see what the paper was about. The main driving force was the change in summer insolation. Currently the Earth is closest to the Sun during the Northern Hemisphere winter. 12,000 years ago the Earth was closest during the Northern Hemisphere summer. Over the Holocene the summer insolation lost 30W/m2.

        Precession didn’t change the distance from the Earth to the Sun, it changed the season the Earth was in while closest to the sun.

        And Kenneth, I will get back to you about the percentage of climate change caused by 0.000001 changes in atmospheric carbon dioxide concentrations. I’ll be tied up for a week, but after that I’ll post it on one of the blog pages.

        1. AndyG55

          “Precession didn’t change the distance from the Earth to the Sun, it changed the season the Earth was in while closest to the sun.

          And the southern hemisphere.?

          It also shows the Holocene optimum.

          Nothing to do with precession.

        2. AndyG55

          “it changed the season the Earth was in”

          You really are a moron if you think the Earth has a season.

          Either make a coherent argument or STFU.!!!

        3. AndyG55

          “I will get back to you about the percentage of climate change caused by 0.000001 changes in atmospheric carbon dioxide concentrations”

          lol.. heading of to visit a Mills and Boon writer , are you. !!

          Another piece of fantasy dribble on its way.

  4. AndyG55

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