UNFCCC%20Article%202%20<=>%20Article%206,%20%20A%20web-based%20climate%20model%20for%20global%20dialogue%20Stabilisation%20scenarios%20under%20Uncertainty

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UNFCCC Article 2 ltgt Article 6, A web-based
climate model for global dialogueStabilisation
scenarios under Uncertainty

• WCCC-2003 ??????
• Ben Matthews matthews_at_climate.be
• Jean-Pascal van Ypersele vanyp_at_climate.be
• Institut dastronomie et de géophysique G.
  Lemaître,
• Université catholique de Louvain,
  Louvain-la-Neuve, Belgium
• Web www.climate.be (UCL-ASTR)
• jcm.chooseclimate.org (interactive model)
• JCM also developed with DEA-CCAT Copenhagen,
  UNEP-GRID Arendal, KUP Bern

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UN Framework Convention on Climate Change
Ultimate objective (Article 2)

• '...stabilization of greenhouse gas
  concentrations in the atmosphere at a level that
  would prevent dangerous anthropogenic
  interference with the climate system.
• Such a level should be achieved within a time
  frame sufficient
• - to allow ecosystems to adapt naturally to
  climate change,
• - to ensure that food production is not
  threatened and
• - to enable economic development to proceed in a
  sustainable manner.'

(technologies, lifestyles, policy
instruments) Emissions pathways(biogeochemical
cycles) Critical Levels (global temperature /
radiative forcing) Critical Limits (regional
climate changes) Key Vulnerabilities
(socioeconomic factors)
inverse calculation
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Role-play on Article 2 with students Louvain la
Neuve, Belgium, Dec 2002, as if COP11, Moscow,
Dec 2005 UNFCCC-style-process,17 teams of
National NGO delegates.

• Quantitative interpretation of Article 2
  Temperature rise (lt1.9C 2100-1990) Sea-level
  rise (46cm 2100-1990)
• Principles for Adaptation funds Tax on
  emissions trading / JI (/CDM?) Percapita
  emissions GDP formula
• Final compromise between Russia and Tuvalu (after
  US quit)
• Equity implications were key aspect of discussion
• Scientific inconsistency maybe realistic in
  policy compromises?
• Delegates used Java Climate Model to explore
  options / uncertainties. By selecting parameters
  / indicators, same model can "justify" diverse
  positions!
• Such "games" also help us to identify scientific
  issues.Reconciling multi-criteria climate
  targets, Conversion to CO2 "equivalents"

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European Union 2 C limit

• EU Council Of Ministers 1996
• "...the Council believes that global average
  temperatures should not exceed 2 degrees Celsius
  above pre-industrial level and that therefore
  concentration levels lower than 550 ppm CO2
  should guide global limitation and reduction
  efforts."
• "This means that the concentrations of all GHGs
  should also be stabilised. This is likely to
  require a reduction of emissions of GHGs other
  than CO2, in particular CH4 and N2O"
• However, widely varying interpretations of
  implications for emissions!
• Why? Java Climate Model may help to
  investigate...

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• Stabilisation scenarios in Java Climate Model
• (Article 2 critical limits gt critical levels gt
  emissions pathways)
• Inverse calculation to stabilise
• CO2 concentration (as IPCC "S"/ WRE scenarios)
• Radiative Forcing (all-gases, "CO2 equivalent")
• Global Temperature (e.g. to stay below 2C limit)
• (Sea-level -difficult due to inertia in ocean /
  ice)
• JCM Core science very similar to IPCC-TAR models,
  but (unlike TAR SYR) includes mitigation of all
  greenhouse gases and aerosols.
• Iterative method to find concentrations attaining
  specified forcing/temperature. Very fast
  response.
• Explore interactively by dragging target curve
  with mouse.
• Or systematically calculate probabilistic
  analysis ...

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Carbon Cycle
Other gases/Aerosols
Climate Model
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Shifting the Burden of Uncertainty

• On average, all sets of scenarios stabilise at
  the same temperature level of 2C above
  preindustrial level. But their uncertainty
  ranges are very different!
• (note picture in abstract book)
• A Temperature limit rather than a Concentration
  limit reduces the uncertainty for Impacts/
  Adaptation...
• (assuming we commit to adjust emissions to stay
  below the limit, as the science evolves)
• ...however this increases the uncertainty
  regarding emissions Mitigation pathways.
• Which is better?

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• 81 Carbon cycle variants
• 3 Land-use-change emissions (Houghton, scaled),
• 3 CO2 fertilisation of photosynthesis ("beta"),
  
• 3 Temperature-soil respiration feedback ("q10"),
• 3 Ocean mixing rate (eddy diffusivity of
  Bern-Hilda model)
• 6 Ratios of emissions of different gases
• Emissions of all gases (including CH4, N2O, HFCs,
  Aerosol and Ozone precursors) reduced by same
  proportion as CO2 with respect to one of six SRES
  baseline scenarios
• note atmospheric chemistry feedbacks included,
  but not varied
• 84 Forcing/Climate Model variants
• 3 Solar variability radiative forcing
• 4 Sulphate aerosol radiative forcing
• 7 GCM parameterisations climate sensitivity,
  ocean mixing/upwelling, surface fluxes (W-R UDEB
  model tuned as IPCC TAR appx 9.1)
• note for sea-level rise, should add uncertainty
  in Ice-melt parameters

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Probability from fit to historical data

• Relative probability of each set of parameters
  derived from inverse of "error" (model - data)
• Measured global temperatures (CRU proxies)
• Measured CO2 concentration (Mauna Loa others)
• Reject low-probability variants (kept 468 / 6804)
• Ensures coherent combinations of parameters, e.g.
  
• More sensitive climate models with higher
  sulphate forcing
• High historical landuse emissions with higher
  fertilisation factor
• Still 2808 curves per plot (including 6 SRES per
  set)So show 10 cumulative frequency bands
  (using probabilities)

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Carbon Cycle
Other gases/Aerosols
Climate Model
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What CO2 level stabilises Tlt 2C ?

• Range 380 - 620ppm,
• Mean 475ppm, Median 450ppm.
• Over 90 of variants are below 550ppm so a
  550ppm target has a high risk of exceeding 2C
• If we want 90 of variants below 2C,the
  concentration should not exceed 400ppm !
• note 550ppm "CO2 equivalent" (all gases) would
  bring us close to 2C. However, to keep the
  temperature level, total radiative forcing (and
  hence CO2 equivalent) must decline gradually.
  This is possible while CO2 remains level, due to
  declining CH4 and O3 (short lifetime gases).

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Article 2 needs global dialogue (Art 6)

• Risk/Value Judgements (including equity
  implications)
• Impacts Key Vulnerabilities? Acceptable level
  of Change?
• Risk Target Indicator? Acceptable Level of
  Certainty?
• (choice of target indicator shifts the burden of
  uncertainty)
• Such risk/value decisions cannot be made by
  scientific experts alone.
• The ultimate integrated assessment model
  remains the global network of human heads.
• To reach effective global agreements, we need an
  iterative global dialogue including citizens /
  stakeholders. The corrective feedback process is
  more important than the initial guess. So let's
  start this global debate!

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Experiment with Java Climate Model
Try JCM at jcm.chooseclimate.org Works in web
browser, Instantly responding graphics, Based on
IPCC-TAR methods / data, Open-source, Labels in
10 languages, 50000 words documentation JCM also
used for teaching in several countriesUniv Cath
de Louvain (BE) Open University (UK), Univ Bern
(CH), Univ Washington (CA),... Role-play
"games" with students may be a useful way to
experiment wth the dialogue process and identify
related scientific questions. Longterm Vision
link such courses to make real global dialogue
linking students around the world. Please join in!
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