Penny Whetton, CSIRO

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INTERIM CLIMATE PROJECTIONS
FOR THE SOUTHERN SLOPES
Penny Whetton (on behalf of the NRM team)
SEPTEMBER 2014
GLOBAL CONTEXT
Global temperatures have increased
Global temperatures have increased
Each of the last three decades has been successively warmer
at the Earth’s surface than any preceding decade since 1850.
The picture of a warming world
The oceans are warming
Sea level is rising
Arctic sea ice is declining
Australian temperatures have risen
2013 - Australia’s hottest year so far
2013 hottest year on record
0.17°C warmer than 2005
and hottest summer (2012/13) and
warmest spring 2013 on record
January heatwave:
Hottest day on record for Australia:
40.3°C on 7 Jan 2013
Highest recorded temperature:
49.6°C on 12 Jan 2013 in Moomba
Atmospheric carbon dioxide (CO2)
The atmospheric concentrations of carbon dioxide, methane,
and nitrous oxide have increased to levels unprecedented in at
least the last 800,000 years.
UNDERSTANDING CLIMATE CHANGE - OBSERVATIONS
Lean et al. (2010)
PROJECTIONS FOR
AUSTRALIA
When using these projections for decision making in NRM
planning you should consider that different models and RCPs
generate a range of projected future climates.
The range of projections will be shown here.
The Climate System
Climate is ‘averaged
weather’, but it is
influenced by many
processes within the
climate system.
Current climate models are
computer programs that
simulate all these
processes, as well as the
weather itself
Our projections are based ‘Coupled modelling intercomparison project –phase
5’, or CMIP5, on simulations of 40+ global climate models.
Confidence is gained from their ability to reproduce observed features of
current climate and past climate changes.
Confidence in model estimates is higher for some climate variables (e.g.,
temperature) than for others (e.g., rainfall).
Weather and climate variability in climate models
Weather and climate variability in models
Representative concentration pathways (RCPs)
o Four RCPs describe plausible
trajectories of future greenhousegas and aerosol concentrations to
the year 2100.
o These are named RCP2.6, RCP4.5,
RCP6, and RCP8.5 in accordance
with the range of radiative forcing
values (in W/m2). Radiative forcing
is a measure of the level of
influence these gases have on the
Earth’s energy balance.
Each RCP is representative of a range of economic, technological,
demographic, and policy futures.
RCP4.5 and RCP8.5 concentration pathways are used for projections
presented here.
PROJECTED TEMPERATURE COMPARED TO THE 1986-2005 PERIOD.
2090 RCP8.5
(10th percentile)
Least warming
Least warming
Most warming
(50th percentile)
c)
4.4°C
Median warming
b)
Latest results (CMIP5)
(90th percentile)
(50th percentile)
Median warming
Most warming
a)
(90th percentile)
(10th percentile)
Earlier results (CMIP3)
d)
Interim projections (08/2013)
e)
4.2°C
Interim projections (08/2013)
f)
Interim projections (08/2013)
Projected temperature change (°C)
The latest model results (CMIP5) show
higher rates of warming are
anticipated in the central regions, and
lower rates in the coastal and
southern regions. This confirms
findings from the earlier studies
(CMIP3).
PROJECTED RAINFALL
Summer
Percentage of models
indicating an increase in
rainfall over the 21st century
(RCP8.5).
Interim projections, 08/2013
Warmer colours (orange →
red) indicate a rainfall
decrease and blue colours,
an increase in rainfall.
Percent of models (40 CMIP5 models)
Rainfall projections vary regionally with differing levels of agreement evident among models.
More than 60 percent of models agree there will be an increase in rainfall in summer over parts
of south-eastern Australia (blue shading).
In some regions there is poor model agreement with regard to the direction of rainfall change
(pale shading).
PROJECTED RAINFALL
Winter
Percentage of models
indicating an increase in
rainfall over the 21st century
(RCP8.5).
Interim projections, 08/2013
Warmer colours (orange →
red) indicate a rainfall
decrease and blue colours,
an increase in rainfall.
Percent of models (40 CMIP5 models)
Less than 10 percent of models indicate an increase in winter rainfall in south-west Western
Australia and parts of southern Victoria (red shading).
In some regions there is poor model agreement with regard to the direction of rainfall change
(pale shading).
PROJECTIONS FOR
SOUTHERN SLOPES CLUSTER REGION
Vic West
In SS-Vic West
But near border, so
SS Vic East also relevant
Tas West
Vic East + SE NSW
Tas East
PROJECTED TEMPERATURE: SOUTHERN SLOPES
Understanding interim projection plots
Interim annual projected temperate change time series to 2100 for mid-range (RCP4.5;
left) and high (RCP 8.5; right)
UNDERSTANDING INTERIM PROJECTION PLOTS
Coloured bars
represent different
emission scenarios
Bars show the range
(10th to 90th percentile)
of model simulations of
20-year average climate.
Bar-extensions represent
the projected range
(10th to 90th percentile) for
individual years, taking into
account year-to year
variability in addition to the
variability in the model
response.
Middle (bold) line is the
median value of the model
simulations over a 20-year
average; half the model
results fall above and half
below this line.
Compared to current conditions, for a given RCP scenario, the bar will move up or down to
reflect the predominant direction of simulated change and will lengthen when models differ
in their response.
PROJECTED RAINFALL
Unlike changes in temperature,
precipitation changes are not directly
influenced by rising greenhouse
gasses.
We also know that regional
precipitation variations can be quite
sensitive to small differences in the
circulation and other processes, as is
evident from the large natural
variability of precipitation over
Australia.
Therefore, with changing circulation in
a warmer climate, different models
can simulate somewhat different
rainfall changes.
Historical climate
Intermediate (RCP 4.5)
Highest (RCP 8.5)
PROJECTED RAINFALL
Range of projected seasonal rainfall for 2090 relative to the 1986-2005 period
(grey bar) for intermediate (gold) and highest (pink) RCPs
SSVW
SSVE + SE NSW
Historical climate
Intermediate (RCP 4.5)
Highest (RCP 8.5)
Increase
SSTE
Decrease
SSTW
SOLAR RADIATION
RELATIVE HUMIDITY
POTENTIAL
EVAPOTRANSPIRATION
Small decreases in relative
humidity are projected during all
four seasons, for intermediate
and high RCPs, however there is a
large spread of model
simulations.
Evapotranspiration is
projected to increase in all
seasons, with larger
increases for the high than
the intermediate RCP.
Historical climate
Intermediate (RCP 4.5)
Highest (RCP 8.5)
Solar radiation increase is more
likely than decrease in all four
seasons, for intermediate and
high RCPs.
.
USING PROJECTIONS INFORMATION
ESTABLISHING THE CONTEXT
What tree species
will be planted in this
bio-sequestration
project?
Will I upgrade my
irrigation infrastructure?
Where should I
purchase my new
farm?
The context
How will crop disease
pressures change in
future?
What varieties of
crop might be
more suitable in
future?
How large
should the
dam be?
How can I best
preserve this
wildlife corridor’?
What is the habitat
suitability for this
species of frog?
What are the stakeholders concerns / issues / decisions??
Risk analysis: future changes
o What time frame that you are interested in.
Establishing the context
Risk assessment
Risk identification
e.g. Identify thresholds (water access,
temperature extremes, fire)
Risk analysis
e.g. address different planning horizons and
potential future scenarios
Risk evaluation
e.g. ranking future climate impacts or
benefit. and identify investment priorities
Risk treatment
e.g. planting suitable tree species.
Process
Monitoring and review
Communication and consultation
e.g. What tree species will be suitable for
bio-sequestration planting in future?
Conclusions
• Navigating the maze of
information about climate change
science is challenging.
• There are many robust findings
about the science. These provide a
basis for action through
adaptation and reducing
emissions.
• Understanding the range of
projected future change will inform
prudent adaptation actions.
By Richard Gifford
CONTACT US
Penny Whetton
e [email protected]
CSIRO advises that the information contained in this publication comprises
general statements based on scientific research. The reader is advised and
needs to be aware that such information may be incomplete or unable to
be used in any specific situation. No reliance or actions must therefore be
made on that information without seeking prior expert professional,
scientific and
technical advice. To the extent permitted by law, CSIRO (including its
employees and consultants) excludes all liability to any
person for any consequences, including but not limited to all losses,
damages, costs, expenses and any other compensation, arising directly or
indirectly from using this publication (in part or in whole) and any
information or material contained in it.
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