Earth’s Climate
Past and Future
Prof. Z. Liu
Dept. Atmospheric and Oceanic Sciences
week
date
topics
1
Sept. 2, 4
2
Sept.9, 11
3
Sept.16,18
4
Sept.23,25
Travel?
5
Sept. 30, Oct., 2
Travel (quiz)
6
Oct., 7, 9
7
Oct. 14, 16(?)
8
Oct 21, 23
9
Oct 28, 30
10
Nov.4, 6
11
Nov.11, 13
12
Nov.18, 20
13
Nov.25, 27
14
Dec. 2, 4
15
Dec. 9, 11
16
Dec. 16, 18
Travel
Travel (quiz)
Thanksgiving
AGU
Text Book
Earth’s Climate, Past and Future,
W.F. Ruddiman
2nd edition, W.H. Freeman and Company
Reading Material
IPCC AR5:
Chapter 5: Information from paleoclimate archives
Grading
Quiz:
1/3
Presentation: 1/3
Term paper: 1/3
Syllabus for AOS528
Part I: Basics of the Climate System
Lecture 1: Introduction: Overview of the climate system (Ch.1)
Lecture 2: Climate Archives and Data (Ch.2)
Lecture 3: Climate Modeling (Ch.2)
Part II: Tectonic-Scale Climate Change
Lecture 4: CO2 and long term climate: last 4.5 Byr (Ch.3)
Lecture 5: Plate tectonics and climate: last 550 Myr (Ch.4)
Lecture 6: The greenhouse earth (Ch.5)
Lecture 7: Back into the icehouse: last 55 Myr (Ch.6)
Quiz 1
Part III: Orbital-Scale Climate Change
Lecture 8: Orbital variations and Insolation Change (Ch.7)
Lecture 9: Orbital control of Monsoon change (Ch.8)
Lecture 10: Orbital control of Ice sheets (Ch.9)
Lecture 11: Glacial cycles and greenhouse gases (Ch.10)
Lecture 12: Carbon pumping into the deep ocean (Ch.10)
Lecture 13: Orbital-scale interactions (Ch.11)
Quiz 2
Part IV: Deglacial and Millennial Climate Changes
Lecture 14: The Last Glacial Maximum (Ch.12)
Lecture 15: The last deglaciation (Ch.13)
Lecture 16: Climate changes in the last 10,000 years (Ch.13)
Lecture 17: Millennial changes (Ch.14)
Quiz 3
Part V: Historical Climate Changes
Lecture 18: The Little Ice Age (Ch.15)
Lecture 19: El Nino, La Nina and Southern Oscillation (Ch.15)
Lecture 20: Impacts of climate on early humans and civilizations (Ch.16)
Lecture 21: Anthropogenic inputs of gases (Ch.16)
Part VI: Future Climate Changes
Lecture 22: The greenhouse debate (Ch.17)
Lecture 23: Climate change in the future 100-1000 years (Ch.18)
Student presentations: IPCC paleo chapter
Lecture 1: Overview of the
Climate System
(Chapter 1)
Global warming?
Global Temp Trend
1.Continetnal warming,
even some cooling,
2. surface more
Why?
Global Prep Trend(?)
Less coherent change,
Why dryer?
Caution: 50-present only!
Local Climate Change
Melting Lake Ice !
Lake
Mendota
Global Warming?!
Different Time Scales in the Past
Different Time Scales in the Past
Atmospheric CO2 Evolution
Tectonic Impact
Abrupt Changes
The Cold Climate
The Dry Climate
Deep Ocean Changes
Modern
LGM
Last 21,000 years
Fig. 1. Paleoclimate time series spanning the last deglaciation and Holocene. From left to right, June insolation at 60ºN (Berger, 1978). Far field
relative sea level records (Fleming et al., 1998; Clark et al., 2009b) (black squares) and Laurentide Ice Sheet volume (Carlson, 2008; Clark,
2009c). Antarctic Dome C CO2 (Monnin et al., 2001). Antarctic Dome C dD (EPICA, 2004). Greenland GISP2 d18O (Grootes et al., 1993).
Hulu (black) and Dongge (gray) Caves speleothem d18O (Wang et al., 2001; 2005). West African terrigenous dust (deMenocal et al., 2000).
ENSO frequency (Moy et al., 2002). Tropical sea surface temperatures (SST): dark blue eastern equatorial Pacific (Lea et al., 2006); blue
Cariaco Basin (Lea et al., 2003); Red western equatorial Pacific (Stott et al., 2007). Bars denote events discussed in text.
Complex System and Interactions
Climate Model for Prediction and Mechanism
Earth System Model
Climate Model and Climate Projection
Decadal (10-30-yr)
Prediction
IPCC, 2007
Test Climate Model Against the Past Obs
Test Climate Model Against Past Obs
21 ka – 0ka
Proxy
Δ 13C
CCSM3
Salinity
AMOC
0ka
21ka
Fig.3: Observation of d13C (left), and model Atlantic salinity (zonal mean) (middle) and the AMOC overturning streamfunction (in
Sv.) (right) at 0ka (upper) and LGM (lower). Model salinity compares well with the d13C reconstruction in the deep ocean, with a
1-km shallowing of the NADW and AMOC.
Observation
Δ 13C
AMOC in Models (PMIP2)
CCSM
HadC
M
MIRO
C
ECBILT_CLIO
0ka
21ka
Otto-Bliesner et al., 2007, GRL
Fig.2: Data-model comparison for
benchmark time series. (a) June
insolation at 60 N (red) and
atmospheric CO2 concentration.
(b)
Sea
level
from
the
reconstruction
(triangle)
and
model (equivalent sea level for
meltwater). (c) Meltwater fluxes in
the model. (d) Pa/Th ratio at
Bermuda as a proxy for AMOC
strength, and model AMOC
transport at 30oS. (e) GISP2
annual surface air temperature in
(d18O) reconstruction and model.
(f) Vostok annual surface air
temperature
in
(d18O)
reconstruction (ref) and model. (g)
Annual SST in Iberian Margin in
reconstruction and model. (h)
Annual SST in Cariaco basin in
reconstruction and model. (i)
Annual rainfall in Cariaco Basin in
reconstruction and model. In (c-i),
reconstruction is in grey, and
model simulations are in color (red
for DGL-A , blue for DGL-B.). (see
Liu et al., 2009 for more details).
Climate Variability
Tropical Pacific SST
El Nino
1935 Texas (Dustbowl)
1997 Kansas
Climate Change and Climate Variability
IPCC, 2007
Sahel Rainfall
Human effect (trend) or/and variability?
July
Charney
Charney???
Giannini et al., 2003: Science
Climate Change: Global to Regional
Global
Wisconsin
US
Madison
Wisconsin Climate Change and North Atlantic Oscillation
?
Temp
NAO
Z. Liu
Wisconsin Temperature: Seasonal
Annual
Winter
Dust Bowl
Summer
http://www.aos.wisc.edu/~sco/divisions/WI-00-temp-djf.gif
Climate Projection and Decadal Prediction
Decadal (10-30-yr)
Prediction
IPCC, 2007
End of Lecture 1