Freshwater Resources Adapting to Climate Change

Jon Spalding

November 20 2007

Motivation

• “By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world population could be under conditions of water stress, the threshold for meeting the water requirements for agriculture, industry, domestic purposes, energy, and the environment (UN Water 2007).”

UN Environment Programme: “Global Environment Outlook 4” Part 4, 2007http://www.unep.org/geo/geo4/media/ aka GEO-4

Overview

1. Where does fresh water come from?

2. How is it used?

3. What impact does climate change have on freshwater availability?

4. What technologies and techniques can help humans to adapt?

Fresh Water Comes From the Ocean

Image credit: http://ga.water.usgs.gov/edu/watercycle.html

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1. Currents and water temperatures determine where and how much ocean water evaporates

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UN Environment Programme: “Global Environment Outlook 4” Part 4, pg. 119 http://www.unep.org/geo/geo4/media/

2. Atmospheric conditions determine where evaporated water is condensed and deposited as rain

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c Kundzewicz, Z.W., L.J. Mata, N.W. Arnell, P. Doll, P. Kabat, B. Jimenez, K.A. Miller, T. Oki, Z. Sen and I.A. Shiklomanov, 2007: Freshwater resources and their management. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 173-210.

3. Freshwater storage quantity and duration in ice and snow is critically dependent on temperatures

• Glacier and snow-fed river systems will experience increased winter runoff, decreased spring/summer runoff, and potential decreased precipitation as temperatures increase

4. Snowmelt and rain form streams and rivers which transport stored water to natural and

man-made lakes

• Increased floods will decrease water quality

• Increasing lake and waterway temperatures will decrease water quality

• Taxed reservoirs will become low quality (ex: Lake Chad)

5. Rainwater infiltrates underground aquifers (recharges ground water)

• Many underground aquifers are heavily taxed in arid climates, and will be increasingly relied upon.

6. Sea level rise

• Saline Intrusion

• Sea level rise may cause problems for waste treatment outlets

Freshwater End-use

• 70% of freshwater is used for agricultural irrigation.

Image credit: http://ga.water.usgs.gov/edu/earthwherewater.html

Another view

• UN Environment Programme: “Global Environment Outlook 4” Part 4, pg. 118 http://www.unep.org/geo/geo4/media/

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*US Geological Survey, “Estimated Use of Water in the United States in 2000” http://pubs.usgs.gov/circ/2004/circ1268/

Trends in population and freshwater withdrawals by source, 1950-2000* (U.S.)

Adaptation

• Flexibility

• Robustness

• Prediction

IWRM

• “capturing society’s views, reshaping planning processes, coordinating land and water resources management, recognizing water quantity and quality linkages, conjunctive use of surface water and groundwater, protecting and restoring natural systems, and including consideration of climate change.”

Methods of extending water resources

• Water conservation

• Reclamation

• conjunctive use of surface and groundwater

• desalination of brackish water

• Rainwater harvesting

• Ocean desalination

Conservation

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Plastic covered, drip irrigation farming in Israel (GEO4 pg 143)

Desalination--a last resort?• Pacific Institute: “Desalination,

With a Grain of Salt A California Perspective”

Could Nuclear Power By The Answer To Fresh Water? http://www.sciencedaily.com/releases/2007/11/071120082429.htm

•Suggested reading: “Power to Save the World” by Gwyneth Cravens. See her post at http://www.amazon.com/Power-Save-World-Nuclear-Energy/dp/0307266567

Example Local Reactions

• Progressive pricing of water proposed in China

• http://www.chinadaily.com.cn/english/doc/2005-05/11/content_441000.htm

• Australia combating 100 year drought with $8 billion water works plan http://www.bloomberg.com/apps/news?pid=20601012&refer=commodities&sid=ayLeMw2JbzeE

• California relies on various resources

– Beuhler, M, “Potential Impacts of Global Warming on Water Resources in Southern California” Water Science and Technology, Vol 47 No 7-8 pp 165-168 (2003)

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• California--the worlds 5th largest economy is facing a water emergency

• Water shortage--a wake up call from global warming?• Definitive lack of preparedness from local and national

government (ex: Georgia, San Diego)• Large scale problem, requires widespread government

action and cooperation from individuals• Discussion question: Can more advanced science and

modeling play a larger role in resource (water) planning as the weather becomes more unpredictable?

• Current trend seems to be that public reaction always follows disasters. Will public ever come to trust and ACT on scientific predictions?

Concluding remarks