Download Welcome to Energy Systems

Energy Systems &
Climate Change
Friday 24 Feb. 2012
Ch.15: Future Climates
Week 7
Dr. E.J. Zita
[email protected]
http://academic.evergreen.edu/curricular/energy/
Today
Questions? Announcements? Logistics …
Field trip planning
Ch.14: Research Projects
Ch.15: Future Climates
Brief reports
Ch.15 Questions
Future Climates
• Temperature and forcing data →
climate predictions?
• Equilibrium Climate models:
– 1-dimensional (variable height)
• 1-layer, 2-layer, many-layer
Equilibrium: 1-dimensional (variable height)
– 2 & 3 dimensional: latitude & longitude
• Time-dependent climate models:
– Validation: calibration, hindcasting
– Projections
• Consequences of climate change
Temperature and CO2 changes track
• t
Past six ice ages to present
Can we accurately predict global
response to climate forcings?
We don’t know enough about:
• Feedbacks
• other nonlinear effects
• clouds, volcanoes, weather patterns…
• human choices
Temperatures in the past 1000 yrs
• t
Models and projections are
possible
• Understand the science as well as
possible
• Make good models, test them against
data, and improve them
• Use models to project future climates,
• for ranges of different variables (human
choices, or forcings by 2100)
One-dimensional equilibrium
models
Equilibrium: not changing in time: power
balance: find the constant temperature
One dimensional: variation with radius, or
height
1D equilibrium model
Two-dimensional models
Variations with height and latitude
Three-dimensional models
Variations with
height, latitude,
and longitude
Time-dependent models
Beyond equilibrium:
In ionized media:
E  
dm
 rate of mass flow
dt
dp
F=
 forces
dt
dB
: Faraday's law: changing magnetic fields induce electric fields
dt
dE
 B  0 0
 0 J
dt
Ampere's law: currents and changing electric fields drive magnetic fields
Induction equation: flows and magnetic fields can cause changes in
each other
Model coupling
Model resolution and speed
• Better spatial resolution requires smaller
grids cells
• Grid cells multiply (3D)
• More grids – or diversity of resolution scales
– requires longer time for computers to run
models
• NCAR’s Community Climate System Model:
1° longitude x 0.3° latitude x (40 ocean + 26
atmospheric) layers = 3 million cells: runs 4 years in
1 day of supercomputer time
Testing models
• Calibration: compare with known simple a
analytic cases
• Hindcasting:
 initialize with old data
 run models forward in time
 improve models until they can
reproduce established observations
Modeled Climate Sensitivity
Discuss transient vs equilibrium response
Validating models:
Atmospheric temperature
Stratosphere
Troposphere
Validating models:
Precipitation vs. Latitude
Validating models:
Temperatures after Pinatubo eruption
Projections of Future climates
Why “projections” and not “predictions”?
Unpredictable factors include:
• Human choices
• Volcanoes, ENSO, NAO
• Feedbacks, other nonlinear effects
Projected climate sensitivity
N.B. These are transients only: add 1.5°C as in Fig.15.4
IPCC future scenarios (AR4)
Which is closest to:
• McKibben’s ideal in Deep Economy?
• Pacala and Socolow’s wedge solution?
• your personal ideal solution?
IPCC CO2 emissions projections
end of oil
BAU
TAR TS Fig.17
New emissions scenarios
IPCC AR5: 2013
CO2 concentrations
IPCC AR5: 2013
Projected global DT
IPCC AR5: 2013
IPCC AR4 DT projections for A1B
Next decade:
2020-2029
End of century:
2090-2099
Temperature increases in °C relative to the period 1980-1999
AR4 SPM1 Fig.6
IPCC AR5 DT projections for RCP4.5
Projected temperature increases for the period 2081–2100, compared
with 1986–2005, for the RCP4.5 scenario. Note that increases are
largest in the Arctic and generally greater on land than over the oceans.
Consequences of
Global Climate Change
Extreme temperature events
Hydrologic cycle & weather
Record Rainfall (Day, Month) November 2006.
Puget Sound with 6-m SLR (http://flood.firetree.net)
Species ranges
Ocean Circulation
http://www.windows2universe.org/earth/Water/ocean_currents.html
Ocean Acidification
Impacts
Climate Change & Society
Tuvalu will be
gone soon.
The people of this
low-lying island
nation have
already been
accepted by
New Zealand as
climate
refugees.
Greatest impacts on people in developing nations, those least
responsible for causing climate disruption (Mumbai, 3 ft of rain in 24 hrs)
Advancing vector-borne infectious diseases (malaria,
dengue, West Nile, hanta,…), increasing heat-wave
deaths
Climate change will
severely impact
food production
in the developing
world
L Brown estimates
10% loss in ag.
productivity for
each 1 oC of
warming
Mountain pine beetle migrates faster
than Cascade lodgepole pine
Record fire seasons in 2005, 2006, 2007
Warming makes hurricanes stronger
Power ~ velocity3

Damage ~ velocity4
http://www.livescience.com/environment/ap_050731_hurricanes_stronger.html
http://wind.mit.edu/~emanuel/home.html
More droughts and floods, as the water
cycle accelerates in a warming world
Workshop:
Planning Powerful Actions
Powerful actions:
• Have clear outcomes
• Maximize benefits, minimize work
• Serve several different values & functions with
one efficient action
• Can be celebrated at the end
Bring ideas for powerful actions next week:
individually, locally, regionally, on larger scales?
Wolfson Research Problems