Climate change and water resources

Climate change and water resources

GEOG 451/551

Issues

What are the potential effects of climate change on water?

Water Is A Scarce Resource

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)

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

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.

2014 drought

What are the Potential Impacts of Climate Change on Water?

Climate Change

Climate Change

Climate Change

Climate Change

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

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

< 5 inches/year

< 15 inches/year

Bloomington ~ 45 inches/year

Precipitation and streamflow are highly seasonal

Fall Winter Spring Summer

Snowmelt-dominated Rain-dominated

Fall Winter Spring Summer

Warmer air temperatures = timing shifts in highly seasonal systems:

– Less snow storage (regime shifts)

– Earlier melt and stream runoff

– Lower snowmelt runoff peak

– Lower summer flows– Warmer stream

temperatures/changes in chemistry

Fall Winter Spring Summer

Snowmelt-dominated

Rain-dominated

Fall Winter Spring Summer

In past decades, we have already seen warmer air temperatures, streamflow timing changes and flow regime shifts

1948 - 2008

Fritze H, Stewart IT, Pebesma E, 2011, J Hydromet

Streamflow TimingRed = Earlier

Orange = Regime ShiftsSnow → Rain

21

Muir Glacier, Alaska (USGS)

1941 2004

Whitechuck Glacier, North Cascades National Park retreated 1.9 km (Wikipedia)

1973 2006

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

Climate Change & Water - The Global Picture

Climate change means that creeping deserts may eventually drive 135 millionpeople off their land, the United Nations estimates. Most of them are in thedeveloping 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

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 seasonal availability 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 andEnvironmental Effects, EPA, December 20, 2007

• 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.

Impacts of Climate Change on Waterin the West

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

“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

• 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.

“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

The New War?

The battles of yesterday were fought overland…. Those of the present centeron oil. But those of the future — a futuremade hotter and drier by climate change in muchof the world — seem likely to focus on water….

In Spain, Water Is a New Battleground, NY Times, June 3, 2008

What about Indiana?

Impacts of Climate Change for the State of Indiana, 2008Average of GFDL, HadCM3 and PCM climate models

What about Indiana?

Impacts of Climate Change for the State of Indiana, 2008

Increase in Spring storm intensities, decrease in frequency

Increase in flooding, dryer soils, more ag. runoff

What about Indiana?

Impacts of Climate Change for the State of Indiana, 2008

Decrease in Summer precipitation

Longer droughts, addition or changes in irrigation

What about Indiana?

Impacts of Climate Change for the State of Indiana, 2008

What about Indiana?

Impacts of Climate Change for the State of Indiana, 2008

More rain, less snowfall → Increase in winter flooding

More rain, less snowfall → Increase in ag. runoffSoil freeze, thaw important for Spring planting

Overall changes in the thermal regimes of streams and rivers

How Will Climate Change Affect Other Water Uses?

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.

Impacts on Uses of Water

Ski Areas

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

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.

Agriculture

“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”.

Impacts on Water Storage Facilities

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

Water Storage

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

• 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

Dana Infante, Peter Esselman, Li Wang

Red areas have habitats potentially most vulnerable to a changing climate.

Aquatic Species