The document summarizes a presentation on the physical and economic impacts of climate change. It discusses the context of resurgent skepticism on climate change and recaps the scientific evidence of rising global temperatures supported by multiple independent records. It outlines projections for significant impacts including rising sea levels that threaten coastal areas, more extreme weather events, effects on global food security, and impacts in regions like Africa, Asia and Australia. It notes Australia's high per capita emissions and contribution to rising CO2 levels. It argues for strong mitigation efforts to transition to a low-carbon economy as a responsible approach and avoid severe economic and social consequences of unchecked climate change in the coming decades and centuries.

1. The physical and economic impacts of
climate change
Solutions and Future Directions in Water, Energy and Waste
Management Forum
Dr Brett Parris
30 August 2011
Rydges Bell City

2. The Big Picture
 Context: Resurgent skepticism. Why?
 Recapping the science
The stakes: Projections and likely impacts
 Australia’s contribution to the problem
 What’s needed?

3. The Big Picture
 Context: Resurgent skepticism. Why?
 Recapping the science
The stakes: Projections and likely impacts
 Australia’s contribution to the problem
 What’s needed?

4. 1990 Liberal Campaign Pledge
 Liberal leader John Hewson took the same policy to the 1993 election
Source: Guy Pearse, http://www.crikey.com.au/2007/11/16/what-turned-the-liberal-party-off-climate-change-action/

5. Incentives for disproving link between
greenhouse gases and climate change
Climate scientists: Fossil‐fuel intensive industries:
• Nobel Prize • Hundreds of billions of $ in future
• Lasting fame revenues
• Thanks of a grateful world • Higher asset values & stock prices
• Huge research grants • Increased ability to attract
talented staff
• Improved brand image
Conclusion?
• VERY strong incentives for
climate scientists to disprove
link. Hasn’t happened.
• VERY strong incentives for
fossil‐fuel intensive industries
to try to disprove or create
doubt about link.
Source: http://nobelprize.org/educational/nobelprize_info/

6. Documenting the backlash

7. Example:
CO2 is natural ‐ how can it be a pollutant?
“Carbon‐dioxide: They call
it pollution. We call it life.”
‐ Competitive Enterprise Institute TV ad.
http://www.youtube.com/watch?v=7sGKvDNdJNA
 A: Whether something is natural or not is irrelevant. It all
depends on its concentration and effects on the system
• Manure is natural. Some on your fields is good. Neck deep isn’t.
• A fraction of a drop of nerve agent VX (less than 10 milligrams) will kill you
stone dead. (0.000014% of 70kg body weight, compared with atmospheric
CO2 concentration 392 parts per million or 0.0392%)
• CO2 is only one (the most important) of around 60 greenhouse gases

8. The Big Picture
 Context: Resurgent skepticism. Why?
 Recapping the science
 The stakes: Projections and likely impacts
 Australia’s contribution to the problem
 What’s needed?

9. U.S. National Oceanic & Atmospheric Administration (NOAA)
State of the Climate 2009
Source: NOAA (2010) 2009 State of the Climate – Highlights http://www.ncdc.noaa.gov/bams‐state‐of‐the‐climate/2009.php

10. U.S. National Oceanic & Atmospheric Administration (NOAA)
State of the Climate 2009
Source: NOAA (2010) 2009 State of the Climate – Highlights http://www.ncdc.noaa.gov/bams‐state‐of‐the‐climate/2009.php

11. Independent records show warming trend
Source: http://www.giss.nasa.gov/research/news/20110113/509983main_adjusted_annual_temperature_anomalies_final.gif

12. Global Temps – Surface & Atmosphere
Source: US National Oceanic and Atmospheric Administration (NOAA)
http://www.ncdc.noaa.gov/sotc/service/global/global-sfc-radiosonde-temp/201001-201012.gif

13. U.S. National Oceanic & Atmospheric Administration (NOAA)
State of the Climate 2009
Source: NOAA (2010) 2009 State of the Climate – Highlights http://www.ncdc.noaa.gov/bams‐state‐of‐the‐climate/2009.php

14. U.S. National Oceanic & Atmospheric Administration (NOAA)
State of the Climate 2009
Source: NOAA (2010) 2009 State of the Climate – Highlights http://www.ncdc.noaa.gov/bams‐state‐of‐the‐climate/2009.php

15. Rising sea‐levels ‐ CSIRO
Source: http://www.cmar.csiro.au/sealevel/sl_hist_last_15.html

16. Is it the sun? volcanos? ….?
Source: Lean, J.L. and Rind,
D.H., (2008) "How Natural and
Anthropogenic Influences Alter
Global and Regional Surface
Temperatures: 1889 to 2006",
Geophysical Research Letters,
Vol. 35, L18701, 16 September,
pp. 6.
http://www.agu.org/pubs/cros
sref/2008/2008GL034864.shtm
l

18. Tipping Points in the Climate System
Lenton et al. (2008) "Tipping Elements
in the Earth's Climate System",
Proceedings of the National Academy of
Science of the United States of Amercia,
Vol. 105, No. 6, 12 February, pp. 1786-
1793.

19. Who will you trust?
 Strong statements affirming the reality of human contribution to
climate change have been released by the National Academies of
Science of: Australia, Belgium, Brazil, Canada, the Caribbean, China,
France, Germany, India, Indonesia, Ireland, Italy, Japan, Malaysia,
Mexico, New Zealand, Russia, South Africa, Sweden, the US and UK.
 There’s ‘scientists’ & scientists. Would you ask a plumber to build
your kitchen cabinets? Would you ask a GP to do your heart surgery?
 When asked “Do you think human activity is
a significant contributing factor in changing
mean global temperatures?” 97% of scientists
with more than 50% of published research
papers on climate change said ‘Yes’.
Doran, P.T. and Zimmerman, M.K., (2009) "Examining the Scientific
Consensus on Climate Change", EOS: Transactions of the American
Geophysical Union, Vol. 90, No. 3, 20 January, pp. 22-23.
http://tigger.uic.edu/~pdoran/012009_Doran_final.pdf
 Where are the published models that say
‘No problem’?

20. The Big Picture
 Context: Resurgent skepticism. Why?
 Recapping the science
The stakes: Projections and likely impacts
 Australia’s contribution to the problem
 What’s needed?

21. Temperatures Projections 1000‐2100
Two separate
considerations for risk
management:
1. Scale of the threat
2. Urgency of the threat
Source: UNEP, (2009) Climate in Peril: A Popular Guide to the Latest IPCC Reports, GRID‐Arendal & SMI Books:
Arendal, Norway & United Nations Environment Program: Nairobi, Kenya, p. 26.

22. European heatwave 2003 …

23. European heatwave 2003 …
Source: Stott, P.A., Stone, D.A. and Allen, M.R., (2004) "Human Contribution to the European Heatwave of 2003",
Nature, Vol. 432, No. 7017, 2 December, pp. 610‐614.

24. Where are we heading?

25. Some global impacts projected for changes in climate
0.5 1 2 3 4 5 5.5ºC
Global mean annual temperature change relative to 1850-1899 ‘pre-industrial’ average (ºC)
Source: IPCC, (2007) "Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth
1
Assessment Report of the Intergovernmental Panel on Climate Change"; Technical Summary, Figure TS.9, p. 43.
‘Pre-industrial’ temperature scale added.

26. Projections for Australia & NZ

27. Coastal vulnerability
tment of Climate Change and Energy Efficiency (2011) Climate Change Risks
alia’s Coast, Canberra.
ww.climatechange.gov.au/en/publications/coastline/climate‐change‐risks‐
alias‐coasts.aspx

28. Projections for Africa

29. Projections for Asia
Source: UNEP, (2009)
Climate in Peril: A Popular
Guide to the Latest IPCC
Reports, GRID‐Arendal &

30. Food Security Outlook

31. Australia’s Garnaut Report
“On a balance of probabilities,
the failure of our generation
on climate change mitigation
would lead to consequences
that would haunt humanity
until the end of time.”

32. The Big Picture
text: Resurgent skepticism. Why?
capping the science
stakes: Projections and likely impacts
tralia’s contribution to the problem
at’s needed?

33. Australia’s emissions per person

34. Australia’s total contributions

35. The Big Picture
text: Resurgent skepticism. Why?
capping the science
stakes: Projections and likely impacts
tralia’s contribution to the problem
at’s needed?

36. Mitigation – the 450 ppm path

37. Australia’s emissions trends
rnaut, R., (2011) The
eview 2011: Australia in
Response to Climate

38. Would strong cuts would kill our economy?

39. How to guarantee mitigation looks like a net cost
“The Treasury
work did not
include the
impacts of
climate
change or the
benefits of
Does the reference case
mitigation”
include the economic
consequences of letting White Paper,
climate change run its p. 4-9.
course? No.

40. Who are the extremists?
 Can’t say whether a response is ‘responsible’ & ‘measured’ as opposed to ‘extreme’
& ‘reckless’ without considering scale and urgency of the threat.
• Eg. Response to invasion fleet? Is failure to mobilise ‘measured & responsible’ or
reckless?
 Who are the ‘extremists’?
• Those arguing we should consider making a fraction of the effort of the WWII
generation to avert a likely irreversible global catastrophe? OR
• Those content to flip a coin to see how we go with more than 2°C warming? (450
parts per million CO2‐eq path gives about 50% chance of staying under 2°C) OR
• Those happy to do nothing and chance the luck of their grandchildren with
whatever the opposite of an ice‐age looks like, with a 4 to 7°C rise?
(5% below 2000 levels by 2020 is on path likely to give 3‐4+ °C warming by 2100.
Much more expensive for next generation to rein it in.)

41. Conclusion: How will we be remembered?
 Under strongest government target (24% below 1990 by 2020):
• “Cost”: 1.1% annual real per capita GNP growth to 2050 instead of 1.2%. So we
wait until 2054 to be as rich as we would have been in 2050.
• Australians on average $27,600 ( or 55%) richer than 2008 by 2050
 In 1942‐43, a previous generation
was spending equivalent to 40% of
national income fighting World War II.
 Our leaders are still treating climate
change like a moderately significant
economic reform, not a national and
global emergency.
 Our children and the poor will pay
the price.
 Surely we can do better.

42. Resources
Intergovernmental Panel on Climate Change http://www.ipcc.ch
Real Climate http://www.realclimate.org
Climate Denial Crock of the Week http://www.youtube.com/user/greenman3610
Skeptical science http://www.skepticalscience.com
Q&As on climate change http://tinyurl.com/BPClimateFAQ
Ian Enting on Plimer http://tinyurl.com/PlimerErrors
Climate Action Network Australia http://www.cana.net.au
My pages: http://www.brettparris.com/climate‐change/
http://tinyurl.com/BPClimateFAQ

43. Slides for questions

44. The Greenhouse Effect

45. Q. How do we
know CO2 is
contributing?
Water vapour absorbs strongly
near 6.3 μm & 2.7 μm & also at
wavelengths greater than 18
μm. CO2 absorbs around 4.3
μm, only weakly between 8-12
μm and most strongly in the
13-17 μm zone, centred on 15
μm right near the peak of the
longwave radiation spectrum
From about 7.7 - 12 μm, the so
called 'atmospheric window',
absorption by water vapour
and CO2 is weak and other
trace gases such as ozone
(peak around 9.6 μm),
methane (7.7 μm) and nitrous
oxide (7.8 μm) absorb more
strongly, despite low
concentrations.
Source: http://en.wikipedia.org/wiki/File:Atmospheric_Transmission.png

46. Cherry‐picking data

47. Temperatures 1000‐2000
Source: Mann, M.E., et al. (2008) "Proxy-based Reconstructions of Hemispheric and Global Surface Temperature Variations over the Past Two
Millennia", Proceedings of the National Academy of Sciences, Vol. 105, No. 36, 9 September, pp. 13252-13257.
http://www.pnas.org/content/early/2008/09/02/0805721105.abstract

48. Q. Isn’t the current change within the
bounds of natural climate change?
 Yes for temperature, but rate of
greenhouse gas accumulation may
be unprecedented.
• But – so what?
• Does that mean it’s OK? No. Sea levels 70
metres higher in the past, temps much
higher, oceans oxygen‐depleted – mass
extinctions.
• Past natural warmings do not mean this
one is natural! Do bushfire investigators
automatically rule out arson just because
many fires are started naturally by lightning?
Of course not!

49. Q: Isn’t the Intergovernmental Panel on
Climate Change (IPCC) unreliable?
 No.
• IPCC isn’t a ‘small group of UN scientists’
• IPCC doesn’t do its own research – it distills and assesses the published, peer‐
reviewed scientific literature over previous years
• IPCC is as reliable as the peer‐reviewed scientific literature ‐
10s of thousands
of papers published by independent scientists in the top scientific journals.
• A couple of errors in more than 3000 pages of reports.
• IPCC summaries approved line‐by‐line by governments (including major fossil
fuel exporters & users such as the US, Russia, Saudi Arabia, China & Australia)
• There is no major struggle within the scientific community about the causes
of climate change, despite media impressions.

50. Q: Aren’t climate models unreliable?
 A: No
• You can’t say anything much about a complex system without a model –
even saying CO2 has no effect. How do they know?
• They’re by no means perfect, but reliable enough.
• There’s not just one model but a dozen or more models produced
independently by different research institutes and while they may disagree on
the details (eg. will how much will rainfall change in a particular region), they
all agree it’s going to get significantly warmer unless greenhouse gas emissions
are reined in.

52. Increasing resolution of climate models

53. Q. Why should we act first?
A. Australia is in no danger of leading
Source: Garnaut, R., (2011) The
Garnaut Review 2011: Australia in
the Global Response to Climate
Change, Cambridge University Press,
Cambridge, Melbourne & New York,
xx + 221 pp.
http://www.garnautreview.org.au/

54. Infrastructure challenges
 Heat stress – eg. Melbourne’s rail network during heatwaves – much
infrastructure not built to tolerate 50+ C°
 Storm & cyclone damage
 Financing – increasing difficulties financing carbon‐intensive
investments; ‘fragile’ asset values
 Insufficient skilled workers
 Electricity grid:
• adaptation to smart grid
• more diverse mix of power sources
• conversion of much of vehicle fleet to electric increasing demand

55. Emissions levels & temperatures
Source: Garnaut, R., (2008) The Garnaut Climate Change Review: Final Report, Cambridge University Press, Melbourne, p. 247.
Meinshausen, M., (2006) "<2°C Trajectories - a Brief Background Note", Paper presented at the KyotoPlus Conference, 28-29
September, Berlin, 11 pp. http://www2.kyotoplus.org/uploads/meinshausen_fin_rev.pdf

56. Uncertainties & risks
 Major areas of (downside) uncertainty still exist in the science:
• the average surface temperature change induced by a doubling of CO2,
• the dynamics of the ice sheets,
• the possibilities of large volumes of methane being released from melting
Arctic permafrost and methane deposits below the ocean floors.
 Uncertainty in the economics:
• Economic models not good at modelling interactions between innovation,
uncertainty, extreme events, financial and asset markets.
• The base‐case projections for GDP growth under the scenario of doing nothing
and allowing climate change to run its course may seriously underestimate the
cumulative losses to GDP from drought, floods, heatwaves, fires, storm surges
and extreme weather events by 2050.

57. END