Climate science: what do we know

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Climate science what do we know?
Lucka Kajfe Bogataj WG2 former Vice-chair,
IPCC University of Ljubljana Slovenia
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21st Century changes in climate

• Four distinctive characteristics
• They are cumulative
• The effects are irreversible
• Large time lags todays actions are tomorrows
  problems
• They are global

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Evolution of international climate policy

• 1898 Swedish scientist Svante Ahrrenius warns
  carbon dioxide from coal and oil burning could
  warm the planet
• 1979 First World Climate Conference organised by
  WMO
• 1988 NASA scientist James Hansen tells U.S.
  Congress global warming "is already happening
  now''
• Creation of the IPCC
• 1992 UNFCCC aims at stabilising atmospheric
  concentrations of GHG
• 1997 UNFCCC parties approve Kyoto Protocol
  mandating emission cuts by industrial nations
• 2005 Kyoto Protocol takes effect

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Changes in global average surface temperature
Eleven of the last twelve years rank among the
twelve warmest years in the instrumental record
of global surface temperature
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It is warmer across the globe than it was a
century ago
Globally averaged, the planet is 0.8C warmer
than it was in 1860
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Drought is increasing most places
Spatial pattern of the monthly Palmer Drought
Severity Index (PDSI) for 1900 to 2002.
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Evidence for reality of climate change
Glaciers melting
Muir Glacier, Alaska
1909 Toboggan Glacier Alaska 2000
1900 2003 Alpine glacier, Austria
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Shrinking Arctic Ice Caps
ACIA (2004, 2008)
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Global natural disasters 1980 2008Geophysical,
meteorological, hydrological events
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IT IS NOT THE SUN.. http//www.pmodwrc.ch/pmod.ph
p?topictsi/composite/SolarConstant
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What are the drivers?

• Population growth, movement and age structures
• Land use change
• Economic growth
• Geo-political changes and realignments
• Trade and subsidies
• Resource competition
• Urbanization
• Technological changes

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Observed
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Drivers of Anthropogenic Emissions
1.5
1.5
1.5
World
1.4
1.4
1.4
1.3
1.3
1.3
1.2
1.2
1.2
1.1
1.1
1.1
1
1
1
Factor (relative to 1990
0.9
0.9
0.9
0.8
0.8
0.8
Emissions
F (emissions)
P (population)
0.7
0.7
0.7
g G/P
0.6
0.6
0.6
h F/G
0.5
0.5
0.5
1980
1985
1990
1995
2000
2005
1980
Raupach et al 2007, PNAS
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Carbon dioxide emissions
Global atmospheric concentrations of greenhouse
gases (GHG) increased markedly as a result of
human activities, with an increase of 70 in
1970-2004
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Fate of Anthropogenic CO2 Emissions (2000-2006)
1.5 Pg C y-1
Canadell et al. 2007, PNAS
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CO2 in the Atmosphere
The fraction of CO2 remaining in the air, after
emission by fossil fuel burning, declines rapidly
at first, but 1/3 remains in the air after a
century and 1/5 after a millennium (Atmos. Chem.
Phys. 7, 2287-2312, 2007).
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Additional physics incorporated in successive
climate models
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Global temperature change
1 0.5 0
Temperature anomaly
1900 1950
2000 Year
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We are running out of atmosphere much faster than
fossil fuels
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Ranges for predicted surface warming
Continued emissions would lead to further warming
of 1.1ºC to 6.4ºC over the 21st century (best
estimates 1.8ºC - 4ºC)
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WAY TO UNKNOWN
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Settlements No-Go Areas
Tropical Hurricanes
Earthquakes
MM modified Mercalli scale
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Settlements No-Go Areas Additional Climate
Change Impacts
Permafrost thaw
e.g.,
Increase in heatwaves
e.g.,
Dangerous sea level rise
e.g.,
Increase in droughts
Increase in heavy rain
e.g.,
e.g.,
Tropical Hurricanes
Earthquakes
MM modified Mercalli scale
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A global shift southward
PRUDENCE project Results based on HadRM3H
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Agro-Economic Vulnerability to Future Climate
Change
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Five human development tipping points

• Reduced agricultural productivity
• Heightened water insecurity
• Increased exposure to extreme weather events
• Collapse of ecosystems
• Increased health risks

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Climate change is a Multiplier for Instability
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Facing the dangers from climate change

• there are only three options
• Mitigation, meaning measures to reduce the pace
  magnitude of the changes in global climate being
  caused by human activities.
• Adaptation, meaning measures to reduce the
  adverse impacts on human well-being resulting
  from the changes in climate that do occur.
• Suffering the adverse impacts that are not
  avoided by either mitigation or adaptation.

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Per capita fossil fuel CO2 emissions
Today 1750-2007
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Probabilities (in ) of exceeding a temperature
increase at equilibrium
Unmanageable
Currently at 430 ppm, rising at 2.5 ppm p.a. and
this rate of increase is increasing
Source Hadley Centre From Murphy et al. 2004
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Probabilities (in ) of exceeding a temperature
increase
Currently at 430 ppm, rising at 2.5 ppm p.a. and
this rate of increase is increasing
Source Hadley Centre From Murphy et al. 2004
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RUSSIAN ROULETTE
Probability to survive 5/6 or 83
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Options for reductions

• Reduce growth of energy use by
• reducing population growth
• reducing growth of GDP/person
• reducing E/GDP ratio by
• increasing efficiency of conversion to end-use
  forms
• increasing technical efficiency of energy end-use
• changing mix of economic activities
• Reduce CO2/E ratio by
• substituting natural gas for oil coal
• replacing fossil fuels with renewables
• replacing fossil fuels with nuclear energy
• capturing sequestering CO2 from fossil-fuel use

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The costs of stabilising the climate are
manageable delay would be dangerous and much
more costly
Damages from climate change rise
disproportionately with temperature !!! (A 25
increase in storm wind speeds is associated with
an almost 7-fold increase in damages to
buildings).

• Climate change could lead to floods, massive
  population shifts, and wars over natural
  resources.
• Ecosystems are unlikely to be able to adapt at
  the rapid rates of change expected.

Stern Review (2006)
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Dreaming about other solutions...
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ADAPTATION

• adjustments in ecological, social or economic
  systems in response to actual or expected climate
  stimuli and their impacts
• ...to moderate damages or to benefit from
  opportunities associated with climate change

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• Considering the risks, why aren't these issues
• higher on policy agendas?

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Science and government are marked by very
distinct behaviours and attributes

• Science
• Probability accepted
• Anticipatory
• Flexibility
• Problem oriented
• Discovery oriented
• Failure and risk accepted
• Innovation prized
• Replication essential for belief

• Government
• Certainty desired
• Time ends at next election
• Rigidity
• Service oriented
• Mission oriented
• Failure and risk intolerable
• Innovation suspected
• Beliefs are situational

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A DOUBLE global crisis unfolds

• In the prime of globalization, we are
  experiencing an accumulation of
• AT LEAST 2 interrelated crises,
• mutually feeding on each other
• Climate change crisis
• Financial and economic crisis
• AND oil and energy crisis, Food (and WATER)
  crisis

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Spend or save? ON CLIMATE CRISIS
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Green investments as a percentage of economic
recovery stimulus packages

Stern
http//image.guardian.co.uk/sys-files/Guardian/doc
uments/2009/02/23/ENVIRONMENTweb.pdf
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• Increasing energy efficiency
• Upgrading physical infrastructure
• Supporting clean technology markets
• Initiating flagship projects
• Enhancing international research and development
  
• Incentivising investment
• Coordinating efforts

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• Increasing energy efficiency (in buildings,
  appliances, fuel efficiency standards, vehicle
  taxation, improving urban planning)
• Upgrading physical infrastructure (electricity
  grid upgrades, public transportation, integrated
  freight transport systems and CO2 pipelines for
  CCS)
• Supporting clean technology markets (facilitate
  the financing of clean technology projects,
  renewable portfolio standards, production tax
  credits and loans)
• Initiating flagship projects (large-scale
  demonstration projects for CCS, concentrated
  solar power, biofuels from ligno-cellulosic
  biomass, power storage and integrated hydrogen
  systems)
• Enhancing international research and development
  (tripling of spending on RD related to energy
  efficiency, renewables, and CCS)
• Incentivising investment (strong commitment to
  pricing carbon across all sectors and regions)
• Coordinating efforts (commitment to an open
  trading system, refrain from discriminatory
  provisions in national stimulus packages.

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Climate Change and the United States
The issue of climate change is one that we
ignore at our own peril Not only is it real,
it's here, and its effects are giving rise to
a frighteningly new global phenomenon the
man-made natural disaster.
Barack Obama, President of the United
States, Jan. 2009 (Inauguration speech)
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Silvio Berlusconi, December 2008
It is absurd, in our times of crisis, to talk
about the emissions of greenhouse gases this is
as if someone, who suffers from pneumonia, would
think about having a perm (permanent hair
styling) rtv.de 15.12. 2008
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Key policies NEEDED

• Improving scientific understanding of the issues
  at stake
• Promoting research development and technology
  transfer
• Informing and educating
• Mainstreaming environmental policies in decision
  making
• Internalising the environmental costs of economic
  activity
• E.g. effective carbon-price signal
• Effective policies are those that provide
  long-term signals and incentives on a predictable
  basis

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Human-driven erosion of resilience
Source IGBP 2007
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CONCLUSIONSConcerning our optionsMitigation,
Adaptation, Suffering

• Were already doing some of each.
• Whats up for grabs is the future mix.
• Minimizing the amount of suffering in that mix
  can only be achieved by doing a lot of mitigation
  and a lot of adaptation.
• Mitigation alone wont work because climate
  change is already occurring cant be stopped
  quickly.
• Adaptation alone wont work because adaptation
  gets costlier less effective as climate change
  grows.
• We need enough mitigation to avoid the
  unmanage-able, enough adaptation to manage the
  unavoidable.