Climate change and water resources

1. Climate change and water resources GEOG 451/551

2. Issues What are the potential effects of climate change on water?

3. Water Is A Scarce Resource

4. Water Is A Scarce Resource In High Demand “Today, in some areas of the Western U.S., existing water supplies are, or will be, inadequate to meet the water demands of people, cities, farms, and the environment even under normal water supply conditions.” U.S. Department of the Interior, “Water 2025: Preventing Crisis and Conflict in the West” (2003)

5. While the U.S. is relatively water rich, the western part of the nation is water poor.

6. Demand For Water Will IncreasePopulation of the West has increased 50% in the last 20 years and is expected to increase another 300% by 2040.

8. 2014 drought

10. What are the Potential Impacts of Climate Change on Water?

11. Climate Change

12. Climate Change

13. Climate Change

14. Climate Change

15. Climate Change • Evidence for Climate Change • The global average temperature increased by more than 1.4°F over the last century • 11 of the 12 years between 1995 and 2006 were among the twelve warmest years since the mid-1800s • Phenological spring in N. hemisphere now comes 6 days earlier • Oceans are warming and becoming more acidic, ice caps are melting, and sea levels are rising • Warming is not due to natural causes • Human produced greenhouse gases are most plausible explanation

16. Most of the West is extremely dry • All areas with more significant precipitation are mountains = water towers • Western United States: snow storage is KEY for water supply Bloomington ~ 45 inches/year < 5 inches/year < 15 inches/year

17. Precipitation and streamflow are highly seasonal Snowmelt-dominated Rain-dominated Fall Fall Winter Spring Summer Winter Spring Summer

18. Warmer air temperatures = timing shifts in highly seasonal systems: Snowmelt-dominated Fall Winter Spring Summer Rain-dominated Fall Winter Spring Summer • Less snow storage (regime shifts) • Earlier melt and stream runoff • Lower snowmelt runoff peak • Lower summer flows • Warmer stream temperatures/changes in chemistry

19. In past decades, we have already seen warmer air temperatures, streamflow timing changes and flow regime shifts Fritze H, Stewart IT, Pebesma E, 2011, J Hydromet 1948 - 2008 Orange = Regime Shifts Snow →Rain Streamflow Timing Red = Earlier

21. 1941 2004 Muir Glacier, Alaska (USGS) 1973 2006 Whitechuck Glacier, North Cascades National Park retreated 1.9 km (Wikipedia)

22. Climate Change and Water “What do you really need to tell people about climate change and water? It’s getting hotter. We’ll get less snow. The snow will melt earlier. That’s all you need to say.” Climate Change - Effects on Southwest Water Resources, Southwest Hydrology , January/ February 2007

23. Climate Change & Water - The Global Picture

24. Climate change means that creeping deserts may eventually drive 135 million people off their land, the United Nations estimates. Most of them are in the developing world. But Southern Europe is experiencing the problem now, its climate drying to the point that it is becoming more like Africa’s, scientists say. • In Spain, Water Is a New Battleground, NY Times, June 3, 2008

25. Water Is Likely to Get Scarcer Due to Climate Change – North America • The Intergovernmental Panel on Climate Change concludes that climate change will strain many of North America’s water resources, increasing the competition for water. • A warmer climate will affect the seasonalavailability of water by increasing evaporation and reducing snowpacks. • The Columbia River and other heavily used water systems of western North America are expected to be particularly vulnerable. • Groundwater-based systems in the Southwest are also likely to be stressed by climate change. • Heavier precipitation will very likely increase waterborne diseases and affect water quality, and higher variability of precipitation will make water management more difficult. Possible Water Resources Impacts in North America, Climate Change – Health and Environmental Effects, EPA, December 20, 2007

26. Impacts of Climate Change on Waterin the West • More heat • Smaller snowpacks • Earlier snowmelt • More evaporation and dryness • More flood-control releases • Less groundwater • More legal restrictions • More droughts • Less Snow, Less Water: Climate Disruption in the West, September 2005, Stephen Saunders and Maureen Maxwell, The Rocky Mountain Climate Organization.

27. West and Southwest • Likely reduction in snowpacks and seasonal shifts in runoff patterns • Possible declines in groundwater recharge - reduced water supplies • Increased water temperatures - further stress on aquatic species • Increased frequency of intense precipitation events - increased risk of flash floods • Possible summer salinity increase in San Francisco Bay and Sacramento/San Joaquin Delta • Intergovernmental Panel on Climate Change, 2001, 2007

28. “By mid-century, the main pulse of the spring snowmelt runoff in the Upper Colorado River Basin is expected to come approximately two weeks earlier than at the present. By the end of the century, snowmelt runoff is expected four weeks earlier in virtually all of the six southwestern states. Run off is also expected to decrease, in part due to higher evaporation rates that come with higher temperatures.” Climate Change - Effects on Southwest Water Resources, Southwest Hydrology , January/ February 2007

29. The entire Jackson-Blackfoot Glacier Basin in Glacier National Park was covered in a single glacier as recently as 1920. Scientists predict both will be gone by 2030.

31. “Climate change has been linked to declining snowpacks, retreating glaciers, and changing patterns of precipitation and runoff. The evidence shows that we are entering a period of water scarcity not seen in our history. The national forests were created in part for ‘securing favorable conditions of water flows,’ the importance of which has grown as populations have grown. We can make a difference by managing national forests and grasslands to restore ecological processes and functions that support clean and healthy streams, lakes, and aquifers.” —Forest Service Chief Gail Kimbell

32. The New War? The battles of yesterday were fought over land…. Those of the present center on oil. But those of the future — a future made hotter and drier by climate change in much of the world — seem likely to focus on water…. In Spain, Water Is a New Battleground, NY Times, June 3, 2008

33. What about Indiana? Average of GFDL, HadCM3 and PCM climate models Impacts of Climate Change for the State of Indiana, 2008

34. What about Indiana? Increase in Spring storm intensities, decrease in frequency Increase in flooding, dryer soils, more ag. runoff Impacts of Climate Change for the State of Indiana, 2008

35. What about Indiana? Decrease in Summer precipitation Longer droughts, addition or changes in irrigation Impacts of Climate Change for the State of Indiana, 2008

36. What about Indiana? Impacts of Climate Change for the State of Indiana, 2008

37. What about Indiana? More rain, less snowfall → Increase in winter flooding More rain, less snowfall → Increase in ag. runoff Soil freeze, thaw important for Spring planting Overall changes in the thermal regimes of streams and rivers Impacts of Climate Change for the State of Indiana, 2008

38. How Will Climate Change Affect Other Water Uses?

39. Impacts on Water Allocation • Competition for the use of limited and declining water resources in the West continues to increase. This competition will likely increase as climate change continues. • With this increased competition and a corresponding increase in administrative enforcement by States, there is likely to be more pressure for water removal from federal lands on or near wilderness • Decreased water availability and changes in the seasonal availability of water will directly affect how these water rights are defined and subsequently administered.

40. Impacts on Uses of Water

41. Ski Areas

42. Recreation Potential increases in camping, hiking, and fishing would draw different outdoor recreation enthusiasts to the area and those activities might be available for a longer period of time during the year. US National Assessment of the Potential Consequences of Climate Variability and Change Educational Resources Regional Paper: Rocky Mountain /Great Basin Region, US Climate Change Science Program / US Global Change Research Program

43. Impacts on Grazing Changes in availability of water and timing of runoff caused by climate change may change the locations of allotments as well as the season of use.

44. Agriculture

45. Impacts on Water Storage Facilities “The snow pack is our major reservoir, and we don’t have artificial reservoirs sufficient in size to manage it in a way that nature manages it for us” Kathleen Miller, National Center for Atmospheric Research and author of the book “Climate Change and Water Resources: A primer for Municipal Water Providers”.

46. Impacts on Water Storage Facilities Overall, temperature increases are expected to decrease the ability of our mountain “water towers” to reliably deliver water in the quantities we have come to expect and when we need it most. Climate Change - Effects on Southwest Water Resources, Southwest Hydrology , January/ February 2007

47. Water Storage Likely to be increased pressure to store and divert more water in existing facilities.

48. Aquatic Species Red areas have habitats potentially most vulnerable to a changing climate. Dana Infante, Peter Esselman, Li Wang • Fish will have to move or die • Spatial limits may shift northward • Some of these species are “dammed off” • Not just fish affected • Plants, phytoplankton, algae as well