Atmospheric and Oceanic Physics: Climate Modelling

Warming Caused by Cumulative Carbon Emissions: the Trillionth Tonne

Speaker: 
Myles Allen
Date: 
Wed, Aug 8, 2007 to Thu, Aug 9, 2007
Location: 
University of New South Wales, Sydney, Australia
Conference: 
1st PRIMA Congress
Abstract: 

The eventual equilibrium global mean temperature associated with a given stabilization level of atmospheric greenhouse gas concentrations remains uncertain, complicating the setting of stabilization targets to avoid potentially dangerous levels of global warming. Similar problems apply to the carbon cycle: observations currently provide only a weak constraint on the response to future emissions. These present fundamental challenges for the statistical community, since the non-linear relationship between quantities we can observe and the response to a stabilization scenario makes estimates of the risks associated with any stabilization target acutely sensitive to the details of the analysis, prior selection etc. Here we use ensemble simulations of simple climate-carbon-cycle models constrained by observations and projections from more comprehensive models to simulate the temperature response to a broad range of carbon dioxide emission pathways. We find that the peak warming caused by a given cumulative carbon dioxide emission is better constrained than the warming response to a stabilization scenario and hence less sensitive to underdetermined aspects of the analysis. Furthermore, the relationship between cumulative emissions and peak warming is remarkably insensitive to the emission pathway (timing of emissions or peak emission rate). Hence policy targets based on limiting cumulative emissions of carbon dioxide are likely to be more robust to scientific uncertainty than emission-rate or concentration targets. Total anthropogenic emissions of one trillion tonnes of carbon (3.67 trillion tonnes of CO2), about half of which has already been emitted since industrialization began, results in a most likely peak carbon-dioxide induced warming of 2○C above pre-industrial temperatures, with a 5-95% confidence interval of 1.3-3.9○C.

Class: 

The Multiple Scales of El Niño

Author: 
Cécile Penland
Date: 
Mon, Jul 30, 2007
Location: 
University of Victoria, Victoria, Canada
Conference: 
Summer School on Tropical Multiscale Convective Systems
Abstract: 

• Climatology (What’s normal?)
• Basic properties of El Niño
• Linear Inverse Modeling
• Non-normal growth and the optimal structure
• Short scales: What constitutes stochastic forcing?
• Long scales: Connection between El Niño and the Pacific Decadal Oscillation

Notes: 
Class: 

Theory of Equatorially Trapped Waves

Author: 
Andrew J. Majda
Date: 
Mon, Jul 30, 2007
Location: 
University of Victoria, Victoria, Canada
Conference: 
Summer School on Tropical Multiscale Convective Systems
Abstract: 

An exposition about waves and PDEs for the equatorial atmosphere and ocean.

Notes: 
Class: 

Waves and Instabilities in Idealized Model Convective Prametrization

Author: 
Boualem Khouider
Date: 
Mon, Jul 30, 2007
Location: 
University of Victoria, Victoria, Canada
Conference: 
Summer School on Tropical Multiscale Convective Systems
Abstract: 

Outline

• Single layer models – CISK-like instability – Stability of adjustment scheme

• One-and-a-half layer models: WISHE waves (LPA, ICAPE, Quasi-Equilibrium Schemes)

• 2-and-a-half-layer models: Stratiform instability

• Multicloud models

Notes: 
Class: 

Atmospheric Convection

Author: 
Phil Austin
Date: 
Mon, Jul 30, 2007
Location: 
University of Victoria, Victoria, Canada
Conference: 
Summer School on Tropical Multiscale Convective Systems
Abstract: 
Outline 1. Satellite/reanalysis views of tropical clouds (MODIS, ISCCP, Bony et al.) 2. Basics: Moist thermodynamics, buoyancy, CAPE, mixing diagrams, conditional/slice instability 3. Impact of clouds on large scale fields ($Q_1,$ $Q_2$, mass flux models) 4. Equilibrium coupling of shallow and deep convection: one cell model 5. Entrainment, detrainment, buoyancy sorting 6. What controls convective cloud top height?
Notes: 
Class: 

Pages