A view from caves
Isotope chemistry, climate change
and the fate of the Chinese dynasties:
Implications for the future of Asian societies
Xianfeng WANG
Earth Observatory of Singapore, NTU
Complexity workshop, March 4-6, 2013
Isotope chemistry, climate change
and the fate of the Chinese dynasties
I. Cave calcite records: Dating & interpretation
II. The Chinese cave records
1. Hundreds of thousands of years
2. Last 1,800 years: ties to Chinese culture
III. Ties to climate and culture elsewhere
Guge Kingdom, Greenland and Mesoamerica
IV. Implications for the future of Asian societies
(1.1)
stalagmites
carbonate dissolution in bedrocks
Ca2+ + 2HCO3-

CaCO3 + H2O + CO2
carbonate precipitation in caves
(figure courtesy of Ronny Boch)
(1.2)
Decay chains
238U
Half-life
4.468 ± 0.005
x109 years
(Jaffey et al. 1971)
234U
245,620
± 250 years
230Th
206Pb
75,580
± 110 years
(Cheng et al. 2000, 2013)
Dating Methods
230Th
dating (U/Th dating or 238U-234U-230Th dating)
From as young as 1 year to over 700 ky
U/Th ~0.25 in the crust
U/Th ~105 in water
1cm
calcite stalagmite
(1.3)
H2O
18O/16O
CaCO3 (+U) + CO2 + H2O =
H2O
Ca2+ (+U6+) + 2HCO3- =
CaCO3 (+U) i + CO2h + H2O
CaCO3
(2.1)
EASM
JJA 850hPa streamline field based on the NCAR/NCEP atmospheric reanalysis
data (Kalnay et al., 1996) during 1971-2000 and regional relief of Earth surface
(Amante, C. and B. W. Eakins, ETOPO1, 2008).
From Y.J. Cai
(2.2)
High summer rainfall
WET
Oxygen isotope (d18O or 18O/16O) values of precipitation
shift to low values during the summer rainy season
a
WET
Stalagmite d18O records from China
Present
(2.3)
Northern Hemisphere summer insolation
300,000
Years ago
The Asian Monsoon faithfully follows changes in the Northern
Hemisphere summer insolation at ~23 ky precession cycle
(Wang Y., et al., 2008, Nature)
Cave Sites
(2.4)
(2.5)
WET
the 1,800-yr long monsoon record from Wanxiang cave
(Zhang et al., 2008, Science)
(2.6)
WET
Drought
the monsoon record from Wanxiang cave vs. the drought/flood
index reconstructed from local historical literatures
(Zhang et al., 2008, Science)
Cave Sites
(2.7)
(2.8)
Wanxiang vs. Dandak cave records
(Berkelhammer et al., 2010, EPSL)
The Wanxiang Cave record
Chinese Culture History
& the Asian Monsoon
(1)
(the Northern Qi, AD 550-577)
(1)
敕勒歌
敕勒川，阴山下，天似穹庐，笼盖四野，
天苍苍，野茫茫，风吹草低见牛羊。
A Shepherd’s Song
By the side of the rill, at the foot of the hill,
The grassland stretches beneath the firmament tranquil.
The boundless grassland lies beneath the boundless skies.
When the winds blow and grass bends low,
My sheep and cattle will emerge before your eyes.
(epiage.com)
(1)
A Shepherd’s Song?
2009
(1)
(2)
the Tang Dynasty (618-907 AD)
(2)
Late Tang weak monsoon period
(2)
In 875 AD:
Locusts swarmed over the land
History as a Mirror
(2)
严重的旱灾(公元 875)引发了濮
州（今河南濮阳东）人王仙芝、冤
句(今山东曹县北)人黄巢领导的
大起义。
Huang, Chao
The Huang Chao Uprising (870s and 880s)
fueled by the drought, led to the end of the
Tang Dynasty.
(3)
the Song Dynasty (960-1279 AD)
Along the River During ChingMing Festival, by Zhang, Zeduan
(3)
Northern Song strong monsoon period
During the Northern Song strong monsoon
period (~AD 960 to 1020), the Chinese population
more than doubled and reached 100 millions.
(3)
Along the River During ChingMing Festival, by Zhang, Zeduan
Rice became the staple of the Chinese diet, and
rice cultivation expanded northwards
substantially (~doubled from AD 975 to AD 1021).
(3)
(4)
the Yuan Dynasty (1279-1368 AD)
(4)
Late Yuan weak monsoon period
(4)
At the end of the Yuan
Dynasty there were a
series of droughts and
peasant uprisings. In 1368
Zhu, Yuanzhang, who led
the uprising, took Beijing.
Zhu, YuanZhang
1st Emperor Ming Dynasty
His parents and older
brother all died during the
the droughts at the end of
the Yuan Dynasty.
(5)
the Ming Dynasty (1368-1644 AD)
(5)
Late Ming weak monsoon period
(5)
The “Chongzhen” Drought (1637 to 1643)
at the end of the Ming Dynasty
Known as one of the most
severe droughts in Chinese
history
Affected more than 20
provinces in both northern
and southern China.
Last Ming Emperor:
Chongzhen (ruled 1628-1644)
(5)
“天降奇荒，所以资(李)
自成也”
计六奇 《明季北略》，卷5
Li, ZiCheng
“The widespread drought
helped the rebel leader, Li
Zhicheng overthrow
Chongzhen in 1644.”
(2.9)
Whereas other factors would certainly
have affected these chapters of
Chinese cultural history, climate
indeed played a significant role.
(2.10)
Boyangfu
(ancient Chinese philosopher)
“水土无所演，民乏财用，不亡何待？昔
伊、洛竭而夏亡，河竭而商亡。”
---《国语·周语》
“Dynasty would collapse, if people were
poor without harvest from water and land.
In the past, the Xia Dynasty collapsed
when Yi and Luo Rivers dried-up, and
the Shang Dynasty collapsed when the
Yellow River dried-up.”
-- Boyangfu (~800 BC)
Guge Kingdom
(3.1)
(3.1)
The Guge Kingdom (古格王国)
(~950 – ~1630)
Ruins of the Guge Kingdom
(3.1)
~950
~1630
Guge Kindom thrived in western
Tibet when monsoon was strong.
(3.2)
Song
Ming-Qing
Song Dynasty: the Medieval Warm Period
Ming & Qing Dynasties: the Little Ice Age
Viking Greenland settlements A.D.
985 to mid-14th (Western) or 15th
century (Eastern)
(D’Andrea et al., 2011, PNAS)
(3.2)
The 9th century collapse and abandonment of the Central Maya Lowlands
(3.3)
multiyear droughts
500
1500
1000
500
0
Year (AD)
(Haug et al., 2003, Science; Medina-Elizalde & Rohling, 2012, Science)
(4.1)
Isotope chemistry, climate change
and the fate of the Chinese dynasties
(4.2)
CO2 and temperature are closely
linked on geologic timescales
100000
200000
300000
400000
500000
600000
700000
800000
0
-5
-10
EPICA Dome C ice core, Antarctica
-15
300
250
200
0
100000
200000
300000
400000
500000
600000
700000
Atm. CO2 (ppmv)
Temp. variation (oC)
0
5
150
800000
Age (year B.P.)
(Jouzel et al., 2007, Nature; Luthi et al., 2008, Nature)
(4.3)
0.4
o
~1ºC warming since
the Industrial
Revolution, and
atmospheric CO2
rose ~100 ppmv.
Average Global Temperature
(wrt 1960-1990 mean)
0.2
0.0
-0.2
-0.4
380
-0.6
360
340
Atmospheric CO2
320
300
1850
1870
1890
1910
1930
1950
1970
1990
Atm. CO2 (ppmv)
Temp. Anomaly ( C)
0.6
280
2010
Year (A.D.)
(Climate Research Unit, University of East Anglia, UK)
Climate change by human influences is exceeding
the bounds of natural variability.
Sustainable food security
in Asia relies heavily on
monsoon rains.
Paleoclimate records can establish the character of natural climate
change. The trend in the last ~100 yrs is clearly anomalous.
It is already challenging to forecast Asian monsoon behaviors
that are caused by current and future anthropogenic forcing.
Predicting any sociological, political and economic
consequences will be even more difficult!
With Thanks:
USA:
China:
Larry Edwards, Wally Broecker, Sidney Hemming
Hai Cheng, Pingzhong Zhang, Yongjing Wang,
Xinggong Kong, Ming Tan, Yanjun Cai
Brazil:
Augusto Auler, Francisco Cruz
Singapore: colleagues at EOS
Funding support:
National Research Foundation of Singapore
National Science Foundation
Gary Comer Science & Education Foundation
... ...
GRUPO BAMBUÍ DE
PESQUISAS ESPELEOLÓGICAS
Zhang et al., 2008, Muescheler et al., 2007, Holzhauser et al., 2005