1. Sunday Age, 28 May 2006
Climate change – the latest news
Paul Holper
CSIRO Marine and Atmospheric Research
Scientists in Schools, Newcastle, 25 October 2007
2. Outline
• Climate change – the basics
• The latest science
• IPCC Fourth Assessment Report
• Climate change in Australia
• Impacts of climate change
• What to do
5. Atmospheric carbon dioxide concentrations
Carbon dioxide concentrations are now greater than at any time
during the past 650,000 years.
6. Svante Arrhenius – “On the influence of
carbonic acid in the air …”
Svante August Arrhenius
b. February 19, 1859, Wijk, Sweden
d. October 2, 1927, Stockholm, Sweden
“Doubling CO2 leads to increase of ~5°C”
7. Longer-term changes
Carbon dioxide and temperature
last 420, 000 years
350
20
temperature ( C)
300
o
CO2 (ppm)
250
10
200
0
150
-10 100
400,000 300,000 200,000 100,000 0
years before present
8. Average Australian surface temperature
Australian annual mean temperatures have increased by approximately
0.9°C since 1910
9. IPCC 2007: Observed changes
• Rises in global average air and ocean
temperatures
• 0.7ºC increase over past 100 years in surface
air temp.
• Eleven of the last 12 years are the warmest since
1850
• Mountain glaciers and snow cover have declined in
both hemispheres
• Annual average Arctic sea ice extent has shrunk
• Increased drying due to higher temperatures and
decreased rainfall has contributed to more intense
and longer droughts since the 1970s
• Frequency of heavy rainfall events has increased
• Hot days and nights and heatwaves have become
more frequent. Cold days and nights and frosts
have become rarer.
10. Decrease in snow, permafrost glaciers &
sea ice
Source: www.ncar.ucar.edu/eo/kids/green/warming6.htm/nsidc.org/data/g00472.html
Muir Glacier August 31, 2004
Muir Glacier, Alaska, August 13, 1941
William O. Field Bruce F. Molnia (USGS).
13. International findings: IPCC 2007
• Warming of the climate system is
unequivocal.
• Very likely that anthropogenic
greenhouse gas emissions caused
most of the warming since the 1950s
(>90% confidence)
• Likely that greenhouse gases alone
would have caused more warming
than observed as volcanic eruptions
and aerosols have offset some of
this warming
14. CO2 concentrations, stabilisation and future temperature
Even if CO2 concentrations are stabilised, temperature
and sea level will continue rising
15. CO2 growth rate rising
Growth rate has risen from <1% pa in the 1900s to > 2.5%
pa from 2000 to 2005.
Rahmstorf et al.
20. Climate change in Australia
CSIRO-Bureau of Meteorology (2007)
Australian Climate Change Science Program
Australian Greenhouse Office, DEWR
• The most comprehensive report on climate
change for Australia
• Detailed 148 page technical report with 291
scientific references. Over 50 authors,
contributors, reviewers and editors.
• 8-page brochure, impacts brochure, CD
www.climatechangeinaustralia.gov.au
21. Projected warming in 2030: 50 percentile, A1B
ºC
A1B mid-range
scenario, best
estimate projected
warming 2.8ºC by
2100
22. Projected warming in 2030: Model range, A1B
Projected warming in 2030: Model range
10 percentile, A1B 90 percentile, A1B
A1B mid-range
scenario, best
estimate projected
warming 2.8ºC by
2100
26. Projected rainfall change 2030:
50 percentile, A1B
Stippling
indicating
where decrease
is ‘likely’ (more
than 67%
probability of
decrease)
No areas show
‘likely’ increase
A1B mid-range
scenario, best
estimate projected
warming 2.8ºC by
2100
27. Comprehensive projections: other variables
• Wind speed mainly increases
• Relative humidity small decreases
• Solar radiation increases in the south
• Potential evaporation increases
• Sea surface temperature increases, especially Tasman sea
28. Impacts of climate change
Australia is already experiencing impacts from recent
climate change
• increasing stresses on water supply and
agriculture, changed natural ecosystems and
reduced seasonal snow cover
Ongoing vulnerability to extreme events
• substantial economic losses caused by
droughts, floods, fire, tropical cyclones and hail
More heat waves, fires, floods, droughts and storm
surges. More intense cyclones and hail storms.
Water security problems to intensify by 2030 in
southern and eastern Australia
Significant loss of biodiversity to occur by 2020 at sites
including the Great Barrier Reef and Queensland
Wet Tropics
Increased risks to major infrastructure
29. What to do?
• Adaptation (‘climate-proofing’)
• maximising opportunities and minimising threats from current and
likely future climatic changes, particularly in vulnerable areas
• Mitigation (reducing greenhouse gas emissions or enhancing
sinks)
• reducing the risk of larger and dangerous changes in climate and
associated impacts to which we cannot adapt
30. Big solutions!
Deploy 16 trillion sunlight-
refracting shades. Each mirror
would span less than a square
metre and block 2% of sunlight.
31. Conclusions
• Climate change is real and underway
• Most of the warming of the past 50 years is due to human activities
Climate change will continue in the 21st century
•
• Detailed information on climate change in Australia is now
available
• Great value in understanding likely impacts to reduce damage and
increase benefits (adaptation)
• Slowing climate change will require large and global reductions in
emissions (mitigation)
32. CSIRO Marine and Atmospheric Research
CSIRO Marine and Atmospheric CSIRO Marine and Atmospheric
Paul Holper
Research Research
Presenter’s name Presenter’s name
Presenter’s title Presenter’s title
Phone: +61 3 9239 4661
Email: paul.holper@csiro.au
Phone: +61 3 9545 2176 Phone: +61 3 9545 2176
Web: www.csiro.au
Email: Name.Name@csiro.au Email: Name.Name@csiro.au
Web: www.cmar.csiro.au Web: www.cmar.csiro.au/group
Thank you
Contact Us
Phone: 1300 363 400 or +61 3 9545 2176
Email: Enquiries@csiro.au Web: www.csiro.au
