Development of Earth System Models and Application to Climate Policy Ronald G. Prinn, MIT IMAGES From Ronald G. Prinn, MIT NASA’s TERRA satellite Victoria University & NIWA Wellington, New Zealand February 23, 2012
WHY DO WE NEED EARTH SYSTEM MODELS? WE DO NOT HAVE ANOTHER EARTH Climate Change WITHOUT HUMAN Urban Air Pollution INFLUENCE TO CALIBRATE THE Water Quality CONFLICT BETWEEN Land Degradation ENVIRONMENT AND Ecosystem Disruption DEVELOPMENT Waste Disposal Energy Food Transportation THE CLIMATE ISSUE Manufacturing EXEMPLIFIES THE Urban Development CHALLEGE FOR Population Grow th SUSTAINING A Potable Water HABITABLE EARTH Human Health
There are now Multiple Indicators of Warming Global Climate: Indicators w ith Positive Trends* Courtesy of Tom Karl, Director, THE THREE WARMEST National Climate YEARS RECORDED Data WITH THERMOMETERS Center, NOAA IN THE LAST 150 Arndt, D. S., M. O. YEARS WERE 1998, Baringer, and M. R. 2005 and 2010 Johnson, Eds., 2010: State of the Climate in 2009. Bull. Amer. Meteor. Soc., 91 (7), S1- S224
There are now Multiple Indicators of Warming Global Climate: Indicators w ith Dow nw ard Trends* Courtesy of Tom Karl, Director, National Climate Data Center, NOAA Arndt, D. S., M. O. Baringer, and M. R. Johnson, Eds., 2010: State of the Climate in 2009. Bull. Amer. Meteor. Soc., 91 (7), S1- S224
WHAT ARE THE RELATIVE ROLES OF HUMAN & NATURAL PROCESSES IN DRIVING THE OBSERVED GLOBAL & CONTINENTAL TEMPERATURE CHANGES FROM 1906 to 2005? Red band: full range for multiple HUMAN-DRIVEN independent model simulations using GLOBAL CLIMATE FORCING natural and human forcing. by greenhouse gases and aerosols is Blue band: full range about for multiple 1.6 W m -2 x 5.1 x 10 14 m 2 independent model simulations using = 8.16 x 10 14 W = 816 TW natural forcing only. Black line: observed changes. (about 52 times current global Ref: IPCC 4th energy consumption) Assessment, Summary for Policymakers, 2007
Even as world leaders have recently discussed tougher targets in Copenhagen, Cancun and Durban, global CO 2 emissions grow th have mostly accelerated. Since its peak in 2007, 35000 emissions in 1.9% AND THE PROBLEM IS FURTHER US dow n 30000 EXACERBATED BY THE RAPID 3.5% about 6.2%; .91% CONTINUING RISE OF THE NON-CO 2 25000 OECD as GASES w hole dow n 20000 MtCO2/year .76% (for policy discussions, levels of non-CO 2 6.4%; CDIAC gases are typically converted to their EIA 15000 Europe dow n equivalent levels of CO 2 that would have 7.2%. But 10000 the same effect on climate; w e are emissions currently at about 474 ppm CO 2 5000 have grow n in equivalents & rising) China and 0 1990 1995 2000 2005 2010 2015 elsew here to offset these reductions.
TWO COMMON WAYS TO EXPRESS POLICY GOALS FOR CLIMATE MITIGATION (1) AIM TO KEEP GLOBAL GREENHOUSE GASES BELOW SPECIFIED LEVELS (for this purpose levels of non-CO 2 gases are typically converted to their equivalent levels of CO 2 that would have the same effect on climate; w e are currently at about 474 ppm CO 2 equivalents) (2) AIM TO KEEP GLOBAL TEMPERATURE INCREASES BELOW SPECIFIED AMOUNTS (relative to say pre-industrial or 1990; w e are currently about 0.8 o C above pre-industrial) BUT THESE SIMPLE CONCEPTS ARE AFFECTED BY THE SIGNIFICANT UNCERTAINTIES IN PROJECTIONS OF ECONOMIES AND CLIMATE: NEED TO EVALUATE POLICIES BASED ON THEIR ABILITY TO LOWER RISK, AND RE-EVALUATE DECISIONS OVER TIME
Discovery of new interactions among natural and human climate system components TO FORECAST CLIMATE CHANGE AND DEVELOP Objective assessment of uncertainty in economic SENSIBLE RESPONSES, WE and climate projections NEED TO: COUPLE THE HUMAN & NATURAL COMPONENTS OF Critical and quantitative THE EARTH SYSTEM. analysis of SUCH INTEGRATED policy proposals ASSESSMENTS HAVE MANY ADDITIONAL POTENTIAL BENEFITS. Understanding connections to other science and policy issues (e.g. air pollution, biodiversity, agriculture, MIT JOINT PROGRAM ON THE energy, w ater quality) SCIENCE & POLICY OF GLOBAL CHANGE http://w eb.mit.edu/global change
WHAT IS THE RELATIONSHIP BETWEEN GREENHOUSE GAS STABILIZATION TARGETS AND FUTURE TEMPERATURE? (non-CO 2 gases converted to their equivalent levels of CO 2 that would have the same effect on climate; currently at about 474 ppm CO 2 equivalents) THE MIT INTEGRATED GLOBAL SYSTEM MODEL http://w eb.mit.edu/global change
HOW ACCURATE ARE CLIMATE FORECASTS? THE MAJOR CLIMATE THESE UNCERTAINTIES FORECAST MODEL SIGNIFICANTLY LIMIT THE UNCERTAINTIES INVOLVE ACCURACY OF CLOUDS, OCEAN MIXING PREDICTIONS OF & AEROSOL FORCING. FUTURE CLIMATE WE USE VERY LARGE ENSEMBLES (400 IN EACH) OF THESE UNCERTAINTIES ARE INTEGRATED GLOBAL SYSTEM CONSTRAINED BY MODEL FORECASTS TO OBSERVATIONS ESTIMATE THE PROBABILITY OF VARIOUS AMOUNTS OF ADDED TO THESE CLIMATE CHANGE under No ARE SUBSTANTIAL Policy (median about 1400 UNCERTAINTIES ppm CO 2 equivalents) and Four IN EMISSION Stabilization Polices (medians FORECASTING about 550, 660, 790, and 900 ppm CO 2 equivalents)
WHAT ARE THE ODDS OF GLOBAL AVERAGE SURFACE AIR WARMING from 1981-2000 to 2091-2100 EXCEEDING VARIOUS LEVELS, WITHOUT (median 1400 ppm-equiv. CO 2 ) & WITH A 550, 660, 790 or 900 median ppm-equiv. CO 2 GHG STABILIZATION POLICY (400 IGSM forecasts per case) Ref: Sokolov et al, Journal of Climate, 2009; Webster et al, Climatic Change, 2011 ∆ T > 2 o C ∆ T > 4 o C ∆ T > 6 o C (values in red relative to 1860 or pre-industrial) No Policy at 1400 100% (100%) 85% 25% Stabilize at 900 (L4) 100% (100%) 25% 0.25% Stabilize at 790 (L3) 97% (100%) 7% < 0.25% Stabilize at 660 (L2) 80% (97%) 0.25% < 0.25% Stabilize at 550 (L1) 25% (80%) < 0.25% < 0.25%
POLES WARM MUCH FASTER THAN TROPICS; IF ICE SHEETS MELT, HOW MUCH SEA LEVEL RISE COULD OCCUR? 7 meters sea level rise STABILITY OF GREENLAND ICE SHEET The last time the polar regions w ere significantly w armer (~4 o C) 5 meters sea level rise than present for an extended period (about 125,000 years ago), STABILITY OF WEST reductions in polar ice volume led ANTARCTIC ICE SHEET to 4 to 8 meters of sea level rise. REFs: Bindschadler et al; ACIA, Impacts of a Warming Arctic, Climate Impact Assessment Report, 2004
THIS WOULD INDUCE EMISSION OVER TIME OF THE 1670 BILLION TONS OF CARBON STORED IN ARCTIC TUNDRA & FROZEN SOILS (TARNOCAI et al, GBC, 2009). THIS RESERVOIR IS ABOUT 200 TIMES CURRENT ANNUAL ANTHROPOGENIC CARBON EMISSIONS. THESE EMISSIONS WOULD INCLUDE METHANE FROM NEW & WARMER WETLANDS. WHAT WOULD HAPPEN IF ARCTIC TUNDRA & REF: ACIA, Impacts of a Warming Arctic, Climate Impact Assessment PERMAFROST THAWS? Report, 2004 IS ARCTIC SEA ICE AT THE END OF WINTER & SUMMER DECREASING? Time series of the percent difference in ice extent in March (the month of ice extent maximum) and September (the month of ice extent minimum) relative to For the period 1979-2011, the the mean values for the rate of decrease of ice extent period 1979–2000. is 2.7% per decade (March) and 11.6% per decade www.arctic.noaa.gov/reportcard/ (September). ArcticReportCard_full_report.pdf
IF THE POLAR LATITUDES WARM TOO MUCH, COULD THE DEEP OCEAN CARBON & HEAT SINK COLLAPSE? Runs of the MIT IGSM 3D OCEAN MODEL OVERTURN DRIVEN w ith 100 years of CO 2 INCREASE then BY SINKING WATER STABILIZATION of CO 2 for 900 years IN THE POLAR SEAS indicate IRREVERSIBLE COLLAPSE of (Norw egian, Greenland, OCEANIC OVERTURN if CO 2 exceeds 620 Labrador,Weddell, Ross) ppm and CLIMATE SENSITIVITY exceeds its current best estimate of 3.5 o C SLOWED BY DECREASED SEA ICE & INCREASED FRESH WATER INPUTS INTO THESE SEAS INCREASED RAINFALL, SNOWFALL & RIVER FLOWS, & DECREASED SEA ICE, EXPECTED WITH GLOBAL WARMING OCEAN BOTTOM DEPTHS (meters) (MIT IGSM 3D OCEAN MODEL Ref: Scott et al, MIT Joint Program Report 148, Climate Dynamics, v30, p441-454, 2008
Hurricane/Typhoon/Cyclone Global Pow er Dissipation Pow er Dissipation Index (PDI) is globally aggregated T ∫ 0 V max 3 dt (a measure of storm destruction) [Courtesy of Tom Karl, Director, National Climate Data Center, NOAA] Thick w avy lines are smoothed versions of thin annual lines using a binomial filter. Thick Adapted/updated from Kossin, J. P., K. R. straight Knapp, D. J. Vimont, R. J. Murnane, and B. A. Harper, 2007: A globally consistent reanalysis lines are of hurricane variability and trends. Geophys. linear Res. Lett., 34, L04815, doi:10.1029/2006GL028836. trends.
HOW CAN WE MANAGE THE CLIMATE ISSUE? IGSM’s Model of ECONOMIC DEVELOPMENT—Emissions Prediction and Policy Analysis (EPPA) Model FOR MORE INFORMATION ON THE GLOBAL CHANGE JOINT PROGRAM SEE: http://globalch ange.mit.edu/
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