1. Climate impacts on building energy use Bas van Ruijven NCAR – CGD – IAM

2. Glacier Lake River Routing Runoff River discharge Urban Land Use Change Wood harvest Disturbance Vegetation Dynamics Growth Competition Wetland CLM CLM as Physical Impacts Model: Part of the integrated assessment framework! Agricultural land use Land management Wood harvest Urbanization Crop/forest yield Building energy use Urban heat waves LU emissions Water availability Renewables potentials CESM iPETS 2Climate impacts on building energy use

3. Change in…CESM CLMU Physical IAM (IMAGE) EconomicIAM (iPETS) … temperature … demand forcooling/heating service … energy use for cooling/heating … energy use for buildings/HHs … energy system … CO 2 emissions … energy expenditures … householdexpenditures … macro-economy(GDP) Horses for courses Climate impacts on building energy use3

4. Model differences CESM CLMU Physical IAM (IMAGE) Economic IAM (iPETS) Main model unitWattEJ/yr$ Time resolution30 minannual Climate informationTemperatureDegreedays- Set pointMin: 13-20 o C Max: 28-38 o C 18 o C- ScopeUrban building energy Energy, emissionsEconomy, energy, emissions Socioeconomic changes -Population, GDP, technology Nr. world regions33269 Sub-categoriesTBD/HD/MDUrban/rural, income - 4Climate impacts on building energy use

5. Conduction Convection Radiation Ventilation The model determines energy demand through Building thermal properties (heat transfer through roofs/walls/floors) Wasteheat factors (efficiency of heating/cooling systems and the conversion of primary to end use energy) Building thermostat settings CLM Building Energy Model K.W. Oleson, G.B. Bonan, J. Feddema and T. Jackson, An examination of urban heat island characteristics in a global climate model, Int. J. Climatol. 31: 1848–1865 (2011)

6. IMAGE - heating 6 oCoCm2m2 kJ/m 2 / o C Floor spaceIntensity van Ruijven BJ, van Vuuren DP, de Vries HJM, Isaac M, van der Sluijs JP, Lucas PL, Balachandra P. Model projections for household energy use in India. Energy Policy 2011;39; 7747-7761.

7. IMAGE - cooling 7 Isaac M, van Vuuren D, P. Modeling global residential sector energy demand for heating and air conditioning in the context of climate change. Energy Policy 2009;37; 507-521.

8. Labor Capital Final Goods Energy Materials Population-Economy-Technology Model iPETS Model CO 2 Emissions Consumption, Investment, Government, Exports/ Imports Final Goods Producers Consumption & Savings Capital & Labor Households Oil, Gas, Coal, Electricity Refined Fuels, Agriculture, Materials Intermediate Goods Producers Land Use 8 O'Neill BC, Dalton M, Fuchs R, Jiang L, Pachauri S, Zigova K. Global demographic trends and future carbon emissions. Proceedings of the National Academy of Sciences 2010;107; 17521-17526.

9. Heating/Cooling impacts in iPETS No explicit modeling of heating/cooling – Six goods for consumption – Electricity, CoalBio, Other energy, Food, Transport, Other Utility  consumption  preference, price, income Simulate decisions under changing circumstances More cooling -> increase in electricity preference Less heating -> decrease in “other energy” preference Results influenced by preference change and prices 9Climate impacts on building energy use

10. Some results Latin America Modeling Project SSP5 socioeconomic baseline GFDL RCP8.5 climate data Climate impacts on building energy use10 Change in…CESM CLMU Physical IAM (IMAGE) Economic IAM (iPETS) … energy use for cooling/heating … energy use for households … CO 2 emissions

11. iPETS SSP5 Baseline Latin America Households final energy 11 Electricity Gases Liquids Biomass Coal Climate impacts on building energy use

12. Smoothed HDD/CDD (GFDL – RCP8.5) 12 HDD CDD Climate impacts on building energy use

13. Change in heating/cooling energy 13 CLMU IMAGE CLMU Climate impacts on building energy use Heating is very similar Cooling different, due to… … thermostat settings, time resolution, buildings/walls, socioeconomic change

14. Change in household energy use 14 iPETSIMAGE Climate impacts on building energy use iPETS preferences changed based on IMAGE Difference mostly due to macroeconomic feedbacks on prices Electricity Biomass Gases Liquids Coal Electricity Biomass Gases Liquids Coal

15. Change in CO 2 emissions 15 Differences due to electricity production structure Climate impacts on building energy use iPETS IMAGE

16. Wrapping up Developing tools to use CLM-U building energy use for iPETS building energy impacts Big differences between models: method and scope Noticeable changes in household energy use Minor impacts on CO 2 emissions Future work: potential impacts on different socioeconomic groups 16Climate impacts on building energy use