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Climate change impacts
Glaciers
Climate science
• The Greenhouse effect:
– Natural:
• Water vapour
• Carbon dioxide
– Human produced:
• Carbon dioxide
• Methane etc.
Human produced
A Question
What is the average temperature of the
Earth?
1 metre above the surface and averaged
over:
• day and night,
• all latitudes and longitudes.
• all seasons
(a) – 15 ° C
(b) – 5 ° C
A Question
What is the average temperature of the
Earth?
1 metre above the surface and averaged
over:
• day and night,
• all latitudes and longitudes.
• all seasons
(a) – 15 ° C
(b) – 5 ° C
Absorption
bands
from the Sun
from Earth
UV
Infra Red
Water
Absorptio
n
CO
2
Absorptio
n
Wavelength
© Australian Bureau of
Meteorology
Absorption bands
by the Sun
from theIllumination
Sun
UV
Infra Red
Water
Absorptio
n
CO
2
Absorptio
n
Wavelength
© Australian Bureau of Meteorology
Absorption bands
from Earth
Radiation from the Earth
UV
Infra Red
(drawn on a different
scale)
Water
Absorptio
n
CO
2
Wavelength
Absorptio
n
© Australian Bureau of Meteorology
The transmittance of
water vapour
Infra Red
Visible
The
spectrum
of
sunlight
UV
Infra Red
Emission spectra for the Sun and Earth
Sun
Diagrams from : Bob
Crowder The Wonders of
the Weather Melbourne,
Bureau of Meteorology
2000: p 22-23.
Earth
Climate science
• Interactions between EMR and the atmosphere:
– Blackbody spectra
– Sun and Earth
(but note that
Earth is less than
a millionth of
the Sun)
• Also note that the IR
absorbed from the
Sun is of much
shorter wavelength
than that emitted by
the Earth
– UV
Vis short IR –
long IR
Climate Models: Results
What is the output of a climate model?
Courtesy of Graeme Pearman
Climate science
• Interactions between EMR and the atmosphere:
– Types of spectra:
This is what we are
interested in.
Climate Real science
• The effect of changes – Feedback and Forcing
– H2O 95% should actually be 90-95% and is for
clouds also.
H2Oleaving 5-10% for
– Can’t simply subtract
GHGs.
CO2
– H2O and CO2 absorb different parts of the IR
radiation spectrum.CH4
Climate Real science
• The effect of changes – Feedback and Forcing
– Anthropogenic CO2 is NOT 3%!
The spectrum of sunlight
A family’s CO2 emissions
0.3 kg per km
0.3 kg per km
per person
4000
1000
km per year
km per year
1200 kg
CO2/year
600 kg
CO2/year
0.5 kg per
kWh
7300
kWh per year
3650 kg
CO2/year
A family’s CO2 emissions
5450 kg of CO2 per year
Over 5 tonnes!
Observed changes
Best estimates
0.6
0.2
o
Anomaly ( C)
0.4
0
-0.2
-0.4
-0.6
1860 1880 1900 1920 1940 1960 1980 2000
Year
Expressing concern
What can we do?
• Sustainable options
This is in sunny Germany!
Radiative forcing
concentrations
Intergovernmental panel on Climate Change (2007) Climate Change 2007: The Physical Science Basis
(Summary for Policymakers) Figure SPM2 p16: Radiative forcing components
Accessed at www.ipcc.ch (11/5/2007)
Contributions to
Climate Forcing
Carbon Dioxide
Greenhous
e
gases
Methane
Chlorofluorocarbons
Nitrous Oxide
Ozone
Black Carbon
Aerosols
Reflective aerosols
Cloud droplet
changes
Land cover changes
Climate Forcing (W/m2)
-1
0
+1
IPCC Predictions…
Methane concentrations
Intergovernmental panel
on Climate Change
(2007) Climate Change
2007: The Physical
Science Basis
(Summary for
Policymakers)
Figure SPM1 p15:
Atmospheric
concentration of CO2
Accessed at
www.ipcc.ch
(11/5/2007)
Carbon dioxide concentrations
Intergovernmental panel
on Climate Change
(2007) Climate Change
2007: The Physical
Science Basis
(Summary for
Policymakers)
Figure SPM1 p15:
Atmospheric
concentration of CO2
Accessed at
www.ipcc.ch
(11/5/2007)
Science behind the model
Reflected by
clouds,
atmosphere
(~23%)
Emitted IR
radiation
Natural
greenhouse
heating
Greenhouse gases
(2.5 Wm-2)
Climate
Models
Input solar
radiation
(100 %)
Absorbed by
atmosphere
(20%) ~60 Wm-2
Measured
absorption
(25%) ~80 Wm-2 ??
Reflected
from surface
(~8%)
Absorbed by
ground
(~49%)
Diagram from : Bob Crowder The Wonders of
the Weather Melbourne, Bureau of Meteorology
2000: p 33.
Climate models have greatly improved
Modelled tropical cyclone
IPCC Predictions from Climate
Research Unit,
East Anglia University
1 metre
2008
0.5 metres in
100 years ?
IPCC SynRep
Climate change impacts
Australia Temperature trend
Climate change impacts
According
to NASA
and the
climate
scientists.
Human induced changes
• Is the climate changing?
IPCC SynRep
Carbon
Cycle
760 increasing
760 at 3.2/year
6.4
60
90
1.4
500
2,000
300
3,000
1.7
1,000
39,000
Cause for concern
• Sceptics, deniers, avoiders
– “We are in a cooling phase” Yes but…
Global CO2 Emissions
http://cdiac.ornl.gov/trends/emis/em_cont.htm
Billions of tonnes of Carbon
10
8
Total Global
CO2 Emissions
6
Developed Countries
4
2
0
1990
Developing Countries
1995
2000
2005
2010
Figure 10.5
Figure 10.8
Figure 10.13
Figure 10.19
Figure 10.24
Figure 10.33
Figure 10.38
Box 10.2, Figure 2
Greenhouse effect
• Most important greenhouse gas (ghg) is water
vapour but its concentration is determined by
temperature
• Important long-lived ghgs are CO2, CH4, N2O
• Absorption by ghgs seen in satellite infrared
spectra
• Absorption proportional to log(concentration), so
doubling ghg concentration gives same heating
‘Warming of the
climate system is
unequivocal, as is
now evident from
observations of
increases in global
average air and
ocean temperatures,
widespread melting
of snow and ice, and
rising global average
sea level.’ (IPCC
2007)
Figure SPM.3
WGI Fig SPM.3
concentrations of carbon dioxide,
methane and nitrous oxide have
increased
markedly as a result of human
activities since 1750 and now far
exceed pre-industrial values
determined from ice cores
spanning many thousands of
years.
The global increases
in carbon dioxide concentration
are due primarily to fossil fuel use
and land-use change, while those
of
methane and nitrous oxide are
primarily due to agriculture.’
WGI Fig SPM.1
Figure SPM.1
Sea ice in Sept 2007
From Stroeve et
al, GRL, 2007
Sept 2005
Observed and projected
Australian rainfall
Best estimate projected
rainfall change for 2070
(from “Climate change in
Australia”)
Observed trend in
annual rainfall
1970-2007
Past Projections
sea level and of
sea-level
projections
sea level
rise
from 1990 to 2100 based on global mean
temperature projections of the IPCC
TAR.
From Rahmstorf,
Science, 2007
From IPCC AR4
Stabilisation scenarios
• 455 ppm CO2-eq in 2005, 379 ppm CO2 conc
• I: CO2-eq stabilisation at 445-490 ppm, emissions peak in 2000-2015,
global CO2 emissions -85% to -50% in 2050, warming of 2.0 to 2.4C above pi
• II: CO2-eq stabilisation at 490-535 ppm, emissions peak in 2000-2020,
global CO2 emissions -60% to -30% in 2050, warming of 2.4 to 2.8C above pi
• Assuming equal per capita emissions, 50% global emission reduction in 2050
means ~90% emission reduction for US and Australia
Likely range of
climate sensitivity
best estimate
SyR Fig SPM.11
Australian greenhouse gas
Dept of Climate Changeemissions
“Tracking to the Kyoto target 2007”
Australian emissions from energy use
and transport have grown at more than
20% per decade. Australia is close to its
Kyoto target only because of one-off
reductions in land clearing.
Sector
% change in 2010
Stationary energy
+56%
Transport
+42%
Land use change
-68%
Total
+8%
in 2020
+64%
+67
-68%
+20%
Other gases with greenhouse potential
Source, IPCC
4AR, SPM, 2007
Relative contribution to warming
Carbon dioxide
Concentration
<1700
2005
Change
Radiative
per year forcing Wm-2
275-285 379 ppmv
1.9 ppmv
+1.66 ±0.17
Methane
715
1774 ppbv ~nil
+0.48 ±0.05
Nitrous oxide
270
319 ppbv
0.83 ppbv
+0.16 ±0.02
CFCs HCFCs
Chlorocarbons
NA
Slightly
negative
+0.32 ±0.03
NA
-0.05 ±0.10
+0.35 ±0.30
Ozone - stratosphere
- Troposphere
HFC, PFC, SF6
Total
NA
NA
10%
+0.017 ±0.002
+2.63 ±0.26
Lifetime and global warming potentials
of selected greenhouse gases
Gas
Symbol Lifetime
Years
Global Warming
Potential
20-years
100-years
Carbon dioxide
CO2
~80
1
1
Methane
CH4
12
72
25
Nitrous oxide
N2O
114
289
298
CFC-11
CCl3F
45
3800
4750
CFC-12
CCl2F2
100
8100
10900
HFC-23
CHF3
270
11700
14800
SF6
3200
23900
16300
Sulphur hexafluoride
IPCC 4AR, Chapter 2, 2007
North Australian tropics annual sea
surface temperature anomaly
(from1961-1990)
http://www.bom.gov.au/cgi-bin/silo/reg/cli_chg/timeseries.cgi
Greenland Mass Loss – From Gravity Satellite
IPCC Predictions on Global
Global Mean
Mean Temperature Temperature
We do
nothing
We BEGIN to stop all emissions
EVENTUALLY
We BEGIN to stop all
emissions NOW
We stop all emissions
NOW
Intergovernmental panel on Climate
Change (2007) Climate Change 2007:
The Physical Science Basis
(Summary for Policymakers)
Figure SPM3 p17: Observed changes
Accessed at www.ipcc.ch (11/5/2007)
IPCC SynRep
IPCC SynRep
Feedback
Increased
Climate
Forcing
Increased
Water
Vapour
Positive
Climate
Forcing
Global
Temperature
Negative
Decreased
Climate
Forcing
Increased
Cloud
Cover
More
Evaporation
Sponsor
Address
Content
Aust. Acad. of
Science
http://www.science.org.au/nova/
Carbon accounting, climate and health,
biodiversity, health, etc.
Australian
Bureau of
Meteorology
http://www.bom.gov.au/climate/
Information about climate
http://www.bom.gov.au/cgi-bin/silo/reg/cli_chg/trendmaps.cgi
Trends maps for Australia’s climat
http://www.greenhouse.gov.au/
Q and A, carbon accounting, energy
http://www.greenhouse.gov.au/
Q and A, carbon accounting, energy, etc
http://www.greenhouse.gov.au/inventory/2003/pubs/inventory2003.pdf
Emission inventory
http://www.greenhouse.gov.au/education/tips.html
What you can do
Hadley Centre,
British
Meteorological
Office
http://www.metoffice.com/research/hadleycentre/pubs/brochures/
Publications
http://www.metoffice.com/research/hadleycentre/models/modeldata.html
Climate predictions
http://www.metoffice.com/research/hadleycentre/obsdata/globaltemperature.html
Global temperatures
CRC G/H Accoun.
http://www.greenhouse.crc.org.au/about%5Fgreenhouse/
Greenhosue, carbon accounting, impacts, etc.
CSIRO Marine
and Atmospheric
Research
http://www.cmar.csiro.au/e-print/open/gh_faq.htm#gh1
Greenhouse questions and answers
http://www.dar.csiro.au/capegrim/ghgasgraphs.html
Greenhouse-gas levels, Cape Grim
http://www.dar.csiro.au/publications/projections2001.pdf
Climate projections
Environment
Canada
http://www.msc.ec.gc.ca/education/scienceofclimatechange/understanding/FAQ/F
AQ-finalenglish.pdf
Greenhouse questions and answers
NOAA
http://www.ncdc.noaa.gov/oa/climate/research/anomalies/anomalies.html
Global data
Princeton
University
http://www.princeton.edu/~cmi/resources/CMI_Resources_new_files/Environ_0821a.pdf
Wedges approach to future energy options
Roy. Soc.
London
http://www.royalsoc.ac.uk/downloaddoc.asp?id=1630
Facts and fiction about climate change
Concerned
Scientists
http://www.ucsusa.org/global_warming/science/global-warming-faq.html
Frequently asked questions
Vict. Government
http://www.greenhouse.vic.gov.au/
Victorian greenhouse strategy, etc.
United Nations
http://unfccc.int/2860.php
Framework Convention on Climate Chnage
http://www.ipcc.ch/
Recent Fourth Assessment Report
Australian
Greenhouse
Office
Milankovitch
Cycles
400
350
CO2 (ppmv)
300
250
200
150
100
Note: Time scales are reversed
50
0
400
350
300
250
200
150
100
Thousands of years before the present
50
0
Figure prepared by Robert Rohde for
Global Warming Art Project
1 metre per
100 years
http://en.wikipedia.org/wiki/Sea_level
Climate models
In brief, each is
• a complex, lengthy computer program,
• incorporating all physical/chemical and
biological processes that drive weather
and climate,
• reproducing the way in which climate
behaves from day to day, and season to
season.
What determines the Earth’s surface
temperature?
For a detailed answer we need to know:
• How much light reaches the Earth?
• How much light reaches the Earth’s Surface?
• How much energy is radiated from the
Earth’s Surface?
Climate models
• These are just
F = ma applied
to moving
fluids.
• This is
conservation of
mass.
• This governs
the way heat
flows between
systems
Dieting Program
86.0
85.0
84.0
83.0
Weight (kg)
82.0
81.0
80.0
79.0
78.0
77.0
76.0
75.0
0
10
20
30
40
50
Days of Dieting
60
70
80
90
10
Science behind the water cycle