Integrated Assessment Modeling: Understanding Interactions of Earth Systems

1. Integrated Assessment Modeling: Understanding Interactions of Earth Systems Interagency Steering Committee Meeting on Multimedia Environmental Modeling Anthony C. Janetos, Director Joint Global Change Research Institute PNNL/UMD 28 November 2011

2. Outline Have been asked to review progress and evolution in IAMs – will use GCAM as an example, but it is not the only capability in the community – IGSM, IMAGE, and others Will briefly review what IAMs are, and how they have historically been used Will briefly review research community’s priorities as articulated for DOE IARP Then examine where we are making progress Suggest where gaps still exist and therefore some directions for the near future

4. What’s in the human Earth system part of a higher resolution IAM, and What’s NOT Outputs of IAMs IAM CO2, GHGs, aerosols, OGs Population Economy Prices, Taxes, e.g. CO2 Labor Productivity Commodity Prices Energy Economic Activity Technology Primary Energy Supply Electric & Refining Policy Crops & Forests, Agriculture The Physical World, e.g. resources, NPP, diffusivity Livestock Other Ecosystem Ecosystems Exogenous Inputs to IAMs (External Forcing)

5. Another View of GCAM

6. The PNNL Global Change Assessment Model (GCAM) • Fully Integrated Agriculture and Land Use Model • 15 Greenhouse Gases and Short-lived Species • Typically Runs to 2100 in arbitrary (1-15 yr) time steps 6 Energy-Agriculture-Economy Market Equilibrium 14 Global Regions – Fully Integrated Explicit Energy Technologies – All Regions

7. 7 A global commitment to stabilizing CO2 concentrations requires a carbon price that escalates over time • Price of carbon should start low and rise steadily to minimize society’s costs. • Eventually all nations and economic sectors need to be covered as the atmosphere is indifferent as to the source of CO2 emissions. • The response to this escalating price of carbon will vary across economic sectors and regions. $102/tC $19/tC $10/tC $4/tC

8. Baseline vs. policy scenario Reference 2.6 W/m2 EMF22 Delay + Overshoot Show global Primary Energy mix for a Reference and a climatepolicycase (e.g. stabilisation at 450 ppm CO2-e)

10. Major Challenges Incorporating Impacts, Adaptation and Vulnerability Extending to Regional Scales and Shorter Times Linking Climate Models and Communities – ESM’s, IAM’s, IAV Strengthening Complex Interactions Among Energy, Environment, Economics Quantifying Uncertainties in Models and Data Advancing Community Modeling Approaches and Accessibility

11. Regional Scales and Shorter Time Steps Global calculations with large geopolitical regions over long time periods are quite reasonable for long-lived GHG’s and strategic questions about mitigation strategies that focus on changes in energy technologies But provides limited information about regional scales and periods of a few years to a few decades Limited insight into how strategies for adaptation to change might interact with mitigation strategies Limited insight into possible limiting environmental factors: water supply, good agricultural soils, climate change itself

12. Creation of a variable time-step version of GCAM One focus has been on technical issues of shortening the time step of the model and incorporating significantly more regional specificity More opportunities to hook into climate models avoids large inconsistencies developing between the models over long time steps Better representation of new technologies and their availability Better representation of vintage (old) technology and retirement/replacement Leading to better representation of total energy consumption and greenhouse gas emissions Flexibility means even tighter time steps (to 1 year) are possible

13. Redevelopment of agriculture and land-use modeling within GCAM Objective: Shift from statistically to physically determined land productivity and create a flexible scale model Step 1: Develop new GCAM AgLU code that allows for subregionalization based on data inputs Step 2: Compile subregionalized input data set • Data for climate-defined agro-ecological zones (AEZs) selected for first application

14. 450 ppm Stabilization Scenario When ALL Carbon is Valued (UCT) Reference Scenario 450 ppm Stabilization Scenario When Terrestrial Carbon is NOT Valued (FFICT) Wise, et al. (2009) Science, 324:1183-1186.

17. Overarching Questions for Regional IAM Studies

18. Regional Integrated Assessment Modeling: the Southeast and Gulf

20. Two Major Goals

22. Incorporating IAV Integrated models have been “soft-coupled” to impacts models before, often for understanding agricultural impacts But in addition, would prefer to examine impacts and potential response strategies to other sectors, some of them of immediate importance to the DOE mission Addressing impacts and adaptation strategies can only sensibly be done with more careful attention to geographic specificity and more sophisticated process representation

23. Effects of Changing Degree Days on Chinese Building Energy Consumption: The Reference Case of China Buildings Fixed HDD of 2158 Fixed CDD of 1046 HDD decreasing from 2158 to 1458 CDD increasing from 1046 to 1746

24. 24 Buildings Demand Modeling ~4000 buildings will be simulated in EnergyPlus to represent the buildings in the RGCAM U.S. test region: 4 climate zones 11 commercial building types 3 residential building types 6-9 sizes within each building type 7-8 vintages of existing buildings and 3 vintages of new buildings Building characteristic vary for each combination of attributes Hourly (8760 hours) electrical output used to calibrate models and determine building weights based on actual weather and actual hourly electric consumption for test region. Our challenge is to pass data back and forth between BEAMS and R-GCAM. Task 4 BEAMS Model Whole Building Engineering Modeling BEAMS Regional Climate Model Task 3

25. Climate Impacts on Agricultural Ecosystems and Bioenergy • EPIC is a process-level model of agricultural production • Initially developed by USDA, now developed at multiple institutions • JGCRI leads development of carbon cycle and greenhouse gases in EPIC • Has been applied in many studies of climate impacts on agriculture and is easily linked to climate model projections • Integration of GCAM and EPIC has a long history • Offline hand-offs of data in prior studies • Mis-match in scale always limited the interaction • New developments in both models provide a new opportunity • Subregionalization of GCAM AgLU and development of R-GCAM • Development of region-wide application system for EPIC through the Great Lakes Bioenergy Research Program

26. EPIC Application for R-GCAM EPIC can simulate multiple potential crops (including bioenergy) and management practices. Results are scalable to political units in R-GCAM This approach will Provide an improved, consistent calibration data set for R-GCAM Establish an approach for process-based climate impacts on agriculture in R-GCAM Zhang et al., 2010, GCB Bioenergy, doi: 10.1111/j.1757-1707.2010.01046.x

27. Linking Climate Models and Other Communities Challenge of beginning to incorporate climate feedbacks on both energy and land processes within the framework of an integrated model Moving from a one-way pass of information (IAM to GCM) to an evaluation of feedbacks in the evolution of the energy-land-climate system Requires moving from reduced form representation of the climate system in IAM frameworks to a sophisticated representations, including coupling with full GCMs/ESMs

28. Why Would We Do This? Existing Earth System Models are already enormous complex Fully coupled AOGCM’s with interactive C (and N) cycles, DGVM’s, including some aspects of disturbance Although there is a growing literature on individual models, as a group, their performance is not yet well understood CMIP5 process really the first major community effort to begin to understand their performance in a systematic way But these models still are specifying initial land-cover, and at most are simulating changes in potential natural vegetation over time And they continue to specify the energy and land-use contributions to increasing CO2 concentrations in the atmosphere

29. A Prototype Integrated Earth System Model (iESM)

30. iESM Preliminary Results

31. Representing Complex Interactions: Energy/Water/Land In the real world, energy demand and use are contingent on the availability of both land and water resources Have typically analyzed these as though they were independent of each other and of variation in the climate system – e.g. assumed that there was plenty of water to satisfy energy demand, or have assumed there was plenty of land to satisfy increased demand for agricultural productivity and bioenergy But how constraining are these factors? Must be included in the accounting of IAMs to understand how they interact with each other and with the climate system

32. Water System The GCAM Systems WATER SUPPLY Land use system Fossil GW & natural lakes Surface Water & GW Recharge Water Supply Desalinization Energy System Reservoirs Water Allocation and Use Water Markets Ocean Carbon Cycle WATER DEMAND Energy Sector Demands Atmospheric Composition, Radiative Forcing, & Climate Industrial Sector Demands Household Sector Demands Water Demand Commercial Sector Demands Economy System Agricultural Sector Demands Terrestrial Carbon Cycle Ecosystem, Navigation, Inter-basin Transfers (prescribed) Climate System Land Use System

33. Water consumption by energy generation technologies Development of water use accounting for the energy sector Davies and Kyle, 2009

34. Some Preliminary Observations from GCAM Water Systems Research Agriculture is the largest user of water (70% withdrawals; 85% consumption) - Bio-energy crops can potentially become important source of water demand in the future Developing countries demands for water can be expected to grow over time, particularly in the first half of the century. Energy systems need water—large source of withdrawals, much smaller consumer. Cooling water demands for power generation (the largest energy user of water) can be expected to grow in the future, particularly in the developing world. New cooling technologies could dramatically reduce fresh water withdrawals, but increase fresh water consumption. NEXT: Allocate water among the competing water users

35. Integrated modeling biofuels andfeedbacks • Objectives of iESM team: • Investigate biofuel sustainabilityunder future climate change. • Study feedbacks from climateand CO2 to the energy markets(phases 2 and 3) • Quantify irrigation demand/costsfor biofuels and energy markets.

36. Disturbances (% of today) Impacts of increased disturbances on mitigation strategy Terrestrial emissions • Terrestrial ecosystems turn into a potentially large source of carbon • Achieving mitigation requires a faster and more pronounced decarbonization, driven by much higher carbon taxes/subsidies. • Higher food and energy prices increase the burden on the population. 200% 100% 70% 2015 Time 2095 Coal & Oil energy share Carbon price

37. Conclusions Interactions of the IAM community and the carbon, Earth system modeling, and remote sensing communities are critically important Development of new model structures to understand the ways in which human decisions can affect land-cover, the carbon cycle, and the climate system over the next several decades Explicit representation of decision-making to explore the consequences of different possible choices Expansion of the kinds of decision-making institutions which are interested in the models – expansion into adaptation issues Backed up by sophisticated representations of processes, constrained by observational data

38. Conclusions Incorporating Impacts, Adaptation and Vulnerability Extending to Regional Scales and Shorter Times • Significant progress in each area highlighted by the IARP report • Rapid expansion of capabilities • Uncovering insights into the interaction of human decision-making and Earth system processes Linking Climate Models and Communities – ESM’s, IAM’s, IAV Strengthening Complex Interactions Among Energy, Environment, Economics Quantifying Uncertainties in Models and Data Advancing Community Modeling Approaches and Accessibility