Earth System ScienceEarth System Science
Dan Lunt, Dan Lunt,
Prof. Paul Valdes, Prof. Tony PayneProf. Paul Valdes, Prof. Tony Payne
Big PictureBig Picture
How do these systems How do these systems work?work?
What are the key drivers?What are the key drivers?How do the different parts How do the different parts
interact?interact?How do we measure and How do we measure and
predict climate?predict climate?What will happen in the What will happen in the
near future?near future?What has happened in the What has happened in the
past?past?
Course aims and Course aims and objectivesobjectives
• Introduce the study of the “Earth System”
• Understand the processes important in influencing the Earth System
• Understand the inter-connectivity of the major components of the Earth system
• Develop an appreciation of the methods used for studying climate
• Understand how and why we use climate models to inform our understanding of the climate system
Lecture seriesLecture series
Lecture 1: Introduction. Lecture 1: Introduction. Lecture 2: Future modelling and the IPCC.Lecture 2: Future modelling and the IPCC. Lecture 3: Past Climate ChangesLecture 3: Past Climate Changes Lecture 4: GeoengineeringLecture 4: Geoengineering Lecture 5: AtmospheresLecture 5: Atmospheres Lecture 6: Energy balance modellingLecture 6: Energy balance modelling Lecture 7: Basics of General Circulation ModellingLecture 7: Basics of General Circulation Modelling Lecture 8: OceansLecture 8: Oceans Lecture 9: Ice sheet dynamics (1)Lecture 9: Ice sheet dynamics (1) Lecture 10: Ice sheet dynamics (2)Lecture 10: Ice sheet dynamics (2)
+ practical sessions+ practical sessions
AssessmentAssessment
Based on practicalsBased on practicals
Write a brief report (in the Write a brief report (in the style of a Nature paper) on style of a Nature paper) on your investigations with the your investigations with the climate model (e.g. a past or climate model (e.g. a past or future simulation).future simulation).
Text booksText books To help see the “overall” picture, you may wish to To help see the “overall” picture, you may wish to
look at:look at: IPCC Working Group 1: Summary for Policymakers IPCC Working Group 1: Summary for Policymakers IPCC Working Group 1: Technical SummaryIPCC Working Group 1: Technical Summary IPCC Working Group 1: Individual chaptersIPCC Working Group 1: Individual chapters
(All available at http://ipcc-wg1.ucar.edu/wg1/wg1-report.html)(All available at http://ipcc-wg1.ucar.edu/wg1/wg1-report.html) Plus: Plus:
McGuffie K. and Henderson-Sellers A., 2005. McGuffie K. and Henderson-Sellers A., 2005. A Climate Modelling Primer.A Climate Modelling Primer. 3rd Ed. 3rd Ed. Wiley.Wiley.
Barry R.G. and Chorley R.J , 2003. Barry R.G. and Chorley R.J , 2003. Atmosphere, weather and climate.Atmosphere, weather and climate. 8th 8th Ed. Routledge.Ed. Routledge.
Bigg G.R. , 1996.Bigg G.R. , 1996.The oceans and climate. The oceans and climate. 2nd Ed. Cambridge University 2nd Ed. Cambridge University Press.Press.
Benn D.I. and Evans D.J.A., 1998. Benn D.I. and Evans D.J.A., 1998. Glaciers and glaciation.Glaciers and glaciation. Hodder Arnold. Hodder Arnold. Kump L.R., Kasting J.F., Crane R.G., 2004. Kump L.R., Kasting J.F., Crane R.G., 2004. The Earth system: an The Earth system: an
introduction to Earth systems scienceintroduction to Earth systems science. 2nd Ed.Prentice Hall.. 2nd Ed.Prentice Hall. Ruddiman W.F., 2001. Ruddiman W.F., 2001. Earth’s climate : past and futureEarth’s climate : past and future. W.H. Freeman . W.H. Freeman
and Company.and Company. Holton, J.R.: An Introduction to Dynamic Meteorology. Academic Press. Holton, J.R.: An Introduction to Dynamic Meteorology. Academic Press.
44thth Ed. Ed. Peixoto & Oort “Peixoto & Oort “Physics of ClimatePhysics of Climate””
Media
Government
“Urgent action is needed to combat climate change”
“Above all, climate change is the greatest challenge facing this generation.”
“Internationally, we will work for an ambitious, fair and legally binding climate change agreement”
Atmospheric CO2
Oceans absorb approx. 25% of emissions, and land (plants) absorb a further 25%
Leaving 50% of emissions to increase atmosphere concentration
CO2 emissions
The Greenhouse Effect
Oldfield, p4
The Earth System
General Circulation Models (GCMs)
2001 2007
2007
2001
1995
1995
1990
1990
History of GCMs
Surface Temperature: observations
Surface Temperature: HadCM3
How good are GCMs?(1) temperature
Precipitation: observations
Precipitation: HadCM3
Seaice: observations vs models
How good are GCMs?(2) Precip and seaice
How good are GCMs?(3) El Nino
Radiative Forcing – anthropogenic component
Historical Forcing and response (century)
Historical Forcing and response (millenium)
Attribution (global)
Attribution (regional)
The future – climate sensitivity
"Prediction is very difficult, especially if it's about the future." --Nils Bohr, Nobel laureate in Physics
"Those who have knowledge, don't predict. Those who predict, don't have knowledge. " --Lao Tzu, 6th Century BC Chinese Poet
"This is the first age that's ever paid much attention to the future, which is a little ironic since we may not have one. " --Arthur C. Clarke
http://www.met.rdg.ac.uk/cag/forecasting/quotes.html
Predicting the Future
SRES (SRES (special report on emissions scenarios) storylines
SRES storylines
Economic growth rapid
Population peak 2050
Technological growth rapid
Capacity building
A1F1: fossil intensive
A1T: non-fossil energy
A1B: Balance
Economic shift - services/information
Population peak 2050
Technology -clean/efficient
Global solutions to sustainability/equity
Economic development regional - disparity
Population continues rising
Technological growth - slow, fragmented
Self reliance, heterogeneity
Economic development intermediate
Population continues rising slowly
Technological growth - diverse
Local and regional solutions to environment/equity
No Additional climate initiatives
SRES storylines summary
A1F1 BAD
B1 GOOD
From Jo House
SRES storylines summary
IPCC SRES
Radiance calibrated lights obtained from night satellite imagery. Situation in 1995/1996 (bottom panel) and illustrative simulation for the SRES A1 scenario's implied GDP growth for 2070 (top panel).
SRES storylines in more detail
IPCC TAR
SRES: Emissions
IPCC TAR synthesis report 2001
Also include emissions scenarios for other greenhouse gases and aerosols.
How to go from emissions to concentrations?
IPCC TAR
Need to consider the components of the carbon cycle important on these timescales – ocean, land, and human pertubations.
Petit et al, Nature, 399, 429-436, 1999.
How to go from emissions to concentrations?
However, we still don’t fully understand the Vostok CO2 curve!!
From Andy Ridgwell
CO2 concentration projections
IPCC TAR
IPCC use relatively simple models to give CO2 concentration scenarios…..
The IPCC Process - summary
Future Climate Predictions - global
Future Climate Predictions – regional(1) temperature
Future Climate Predictions – regional(2) Precipitation and cloud cover
[stippling – at least 80% agree on sign of change]
Future Climate Predictions – regional(3) Ocean circulation
Summary Summary Summary Summary The atmospheric composition has changed
over the last century.
The climatic consequences of these variations can be represented using numerical models.
These models do a relatively good job of the last century (millenium) compared to observations.
Climatic change over the last century is predominantly anthropogenic.
Future scenarios of atmospheric composition have been developed.
Some modelled consequences of these future changes are robust, others less so.
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