Integrated Assessment of Climate Change

INTEGRATION OF THE SCIENCE AND ECONOMICS OF CLIMATE CHANGE Image courtesy of NASA TERRA Satellite. MIT JOINT PROGRAM ON THE SCIENCE & POLICY OF GLOBAL CHANGE Founded in 1991 Supported by 5 federal Agencies, a consortium of 21 Industries, and a Foundation Discovery of new interactions among natural and human climate system components Objective assessment of uncertainty in economic and climate projections Critical and quantitative analysis of policy proposals Understanding connections to other science and policy issues (e.g. air pollution) The major analytical tool of the Global Change Joint Program is the Integrated Global System Model (IGSM) Joint Program on the Science and Policy of Global Change HOW ACCURATE ARE CLIMATE FORECASTS? THE MAJOR CLIMATE FORECAST MODEL UNCERTAINTIES INVOLVE CLOUDS, OCEAN MIXING & AEROSOL FORCING. THESE UNCERTAINTIES ARE CONSTRAINED BY OBSERVATIONS ADDED TO THESE ARE SUBSTANTIAL UNCERTAINTIES IN EMISSION FORECASTING THESE UNCERTAINTIES SERIOUSLY LIMIT THE ACCURACY OF PREDICTIONS OF FUTURE CLIMATE WE USE VERY LARGE ENSEMBLES OF IGSM RUNS TO ESTIMATE THE PROBABILITY OF VARIOUS AMOUNTS OF CLIMATE CHANGE 1200 1000 x Mean +/- Standard Deviation 95% Probability Bounds IPCC SRES Scenarios 800 600 400 x WE USE ECONOMIC MODEL TO PREDICT EMISSIONS OF ALL MAJOR CLIMATEFORCING & POLLUTING GASES AND AEROSOLS (e.g. EPPA cf. SRES) 200 0 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 Year Global CO2 Emissions (PgC/yr) Global NOx Emissions (Tg/yr) CO2 Emissions (Gt C) 50 40 Mean +/- Standard Deviation 95% Probability Bounds IPCC SRES Scenarios 30 20 10 0 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 Year Global SO2 Emissions (Tg/yr) MIT IGSM CALCULATES THE PROBABILITY OF VARIOUS AMOUNTS OF CLIMATE CHANGE: 1990-2100 Image removed due to copyright considerations. See Figure 2. Webster et al., Climatic Change, 61, 295320, 2003. MIT IGSM CALCULATES THE PROBABILITY OF VARIOUS AMOUNTS OF CLIMATE CHANGE BY LATITUDE: 1990-2100 Image removed due to copyright considerations. See Figure 3. Webster et al., Climatic Change, 61, 295320, 2003. VULNERABLE HIGH LATITUDE SYSTEMS REF: ACIA, Impacts of a Warming Arctic, Climate Impact Assessment Report, 2004 September 1979 DEPLETION OF SUMMER SEA ICE Images courtesy of ACIA. September 2003 STABILITY OF ANTARCTIC ICE SHEET Image removed due to copyright considerations. See Figure 1. Bindschadler, R. A., R. B. Alley, J. Anderson, S. Shipp, H. Borns, J. Fastook, S. Jacobs, C. F. Raymond, What is happening to the west antarctic ice sheet?, Eos Trans. AGU, 79(22), 257-257, 10.1029/98EO00188, 1998. STABILITY OF TUNDRA & PERMAFROST 3-DIMENSIONAL OCEAN IN IGSM ENABLES TREATMENT OF THE STABILITY OF THE OCEANIC CARBON & HEAT SINK ⇑ DRIVEN BY SINKING WATER IN THE POLAR SEAS (Norwegian, Greenland, Labrador, Weddell, Ross) SLOWED BY DECREASED SEA ICE & INCREASED FRESH WATER INPUTS INTO THESE SEAS ⇑ ⇑ OCEAN BOTTOM DEPTHS (meters) (MIT 3D OCEAN MODEL) INCREASED RAINFALL, SNOWFALL & RIVER FLOWS, & DECREASED SEA ICE, EXPECTED WITH GLOBAL WARMING THE IGSM INCLUDES A RECURSIVE DYNAMIC COMPUTABLE GENERAL EQUILIBRIUM ECONOMICS MODEL (EPPA) THE IGSM ECONOMICS MODEL HAS THE NEEDED SECTORAL DETAIL TO ANALYSE EXISTING OR PROPOSED POLICIES 2.00 NO EMISSION TRADING e.g. Welfare (Consumption) Change Under Kyoto without EMISSION USA & TRADING Australia (EU GETS ALL RUSSIAN PERMITS) % Consumption Change 1.50 1.00 0.50 0.00 2010 -0.50 EUR EET JPN CAN FSU CHN IND MES MEX 2015 -1.00 2020 ⇑⇑ -1.50 -2.00 OIL EXPORTERS HIT HARDEST -2.50 -3.00 1.00 % Consumption Change ECONOMICS MODEL (EPPA) ESTIMATES COUNTRY COSTS OF SPECIFIC POLICY PROPOSALS 0.50 0.00 -0.50 -1.00 -1.50 -2.00 -2.50 -3.00 EUR EET JPN CAN FSU CHN IND MES MEX ⇑ ⇑ EUR & FSU BENEFIT SUBSTANTIALLY 2010 2015 2020 HOW CAN WE EXPRESS, IN EVERY-DAY LANGUAGE, THE VALUE OF A CLIMATE POLICY UNDER UNCERTAINTY? What would we Compared with buy with STABILIZATION NO POLICY of CO2 at 550 ppm? A NEW WHEEL with lower odds of EXTREMES