1. Energy-Water-Climate Change Scenario Gary Graham, SPSG Chair W ESTERN E LECTRICITY C OORDINATING C OUNCIL

2. Overview Background Currently identified issues New issues? Next steps 2 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

3. EWCC Scenario—Background October, 2014 Energy- Water- Climate Change Workshop, Salt Lake City December, 2014 Scenario Planning Workshop December, 2014 First Draft of Scenario January, 2015 Second Draft of Scenario February, 2015 SPSG Discussion 3 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

4. Currently-Identified Issues Temperature Change How should a temperature rise of 3 °F. by 2034 be characterized? Are we appropriately addressing broader “climate change” or only average global temperature increase? Causality How should the scenario treat GHG? How should the scenario treat human influence? Reliability Risks How do “system issues” translate into “reliability risks?” To what extent are weather-related outages a reliability risk? Water Nexus Have we adequately addressed West- wide impacts? Have we adequately described the importance and nexus of energy and water? 4 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

5. Currently-Identified Issues Temperature Change How should a temperature rise of 3 °F. by 2034 be characterized? Are we appropriately addressing broader “climate change” or only average global temperature increase 5 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

6. EPA Temperature Projections From IPCC Emission Models 6 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Highest Emissions = +3 0 F in 2034

7. Temperature Change 3°F is our TARGET Consistent for 2035 for highest emissions: Consistent with lowest for 2100; Provides greatest credible POTENTIAL for risks: If early indicators show reduced then easier to adapt planning. 7 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

8. Temperature Change Temperature primary driver but clearly and scientifically it interacts with, and is coupled with precipitation changes, with both contributing to extreme weather events. 8 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

9. Causality How should the scenario treat GHG? How should the scenario treat human influence? 9 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

10. Causality We have to acknowledge that GHG are the most scientifically credible and almost universally accepted cause of climate change or the scenario will not be received as credible by most of our partners as well the scientific and environmental community. 10 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

11. Causality But we agreed to and do not have to dwell on the human causes of GHG other than as they related to several of the scenario drivers, AS WE DID WITH THE ORIGINAL SCENARIOS, and to acknowledge several early indicators policies that relate to humans causes 11 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

12. Reliability Risks How do “system issues” translate into “reliability risks?” To what extent are weather-related outages a reliability risk? 12 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

13. Reliability Risks Climate Changes Temperature, Precipitation, Extreme Weather Impacts (Heat Waves, Droughts, Too much water, Fire, Floods etc) Can Cause Reliability Risks Event intensity, duration, onset timing et. And existing or purposeful planning 13 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

14. Reliability Risks 14 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

15. Water Nexus Have we adequately addressed potential West-wide impacts to reliability? Have we adequately described the importance and nexus of energy and water? 15 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

16. Water Nexus Yes, given our focus on the nexus and the timing and capacity constraints Yes, adequately, but could be improved 16 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

17. New Issues Are there other questions, issues or additions that the SPSG should consider for the Scenario? 17 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

18. Next Steps (Proposed) SPSG Comments Feb 20 “Final” Scenario Mar 6 MDTF Modeling Parameters May 5 18 W ESTERN E LECTRICITY C OORDINATING C OUNCIL