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Chinese scientists find 2,000 years of not-hockey stick

Posted By Jo Nova On August 24, 2017 @ 4:57 am In Global Warming | Comments Disabled

There was no Medieval Warm Period in China. No little ice age either. Not warm in Roman times either.

Obviously CO2 controls this climate.

China, Year 0 - 2000, MWP, LIA, Graph, paleohistory, climate change.

(Click to enlarge)

Quansheng et al show that weather is lumpy, that modern warming is a lot like past warming. They go so far as to say that there are regular cycles and hint that sun might have something to do with it, and volcanoes.

“…centenial variation is significantly correlated with long-term changes in solar radiation—especially cold periods, which correspond approximately to sunspot minima, as well as the frequency of large volcanic eruptions.”

They go on to say that rate of warming was about half a degree per century lately. It may have been  the fastest rate, but then again, it may not. It was hard to tell with the error bars being so wide. It was all done with proxies and has a ten year resolution. Obviously it is in need of having homogenadjustoided thermometer data added after 1960 as is the custom in climate science.

The Medieval Warm Period was global

Abstract

This paper presents new high-resolution proxies and paleoclimatic reconstructions for studying climate changes in China for the past 2000 years. Multi-proxy synthesized reconstructions show that temperature variation in China has exhibited significant 50–70-yr, 100–120-yr, and 200–250-yr cycles. Results also show that the amplitudes of decadal and centennial temperature variation were 1.3°C and 0.7°C, respectively, with the latter significantly correlated with long-term changes in solar radiation, especially cold periods, which correspond approximately to sunspot minima. The most rapid warming in China occurred over AD 1870–2000, at a rate of 0.56° ± 0.42°C (100 yr)−1; however, temperatures recorded in the 20th century may not be unprecedented for the last 2000 years, as data show records for the periods AD 981–1100 and AD 1201–70 are comparable to the present. The ensemble means of dryness/wetness spatial patterns in eastern China across all centennial warm periods illustrate a tripole pattern: dry south of 25°N, wet from 25°–30°N, and dry to the north of 30°N. However, for all centennial cold periods, this spatial pattern also exhibits a meridional distribution. The increase in precipitation over the monsoonal regions of China associated with the 20th century warming can primarily be attributed to a mega El Ni˜no–Southern Oscillation and the Atlantic Multidecadal Oscillation. In addition, a significant association between increasing numbers of locusts and dry/cold conditions is found in eastern China. Plague intensity also generally increases in concert with wetness in northern China, while more precipitation is likely to have a negative effect in southern China.

 

 

 

 

 

 

 REFERENCE:

Quansheng Ge et al, Characteristics of temperature change in China over the last 2000 years and spatial patterns of dryness/wetness during cold and warm periods, Advances in Atmospheric Sciences (2017). DOI: 10.1007/s00376-017-6238-8

h/t Climate Depot, GWPF.

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