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Peak Water Limits: New Constraints, New Solutions. Dr. Peter H. Gleick Water in a World of Seven Billion, Calgary. What Does “Peak Water” Mean?. We’ll never “run out” of water overall. It is (mostly) renewable.
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Peak Water Limits: New Constraints, New Solutions Dr. Peter H. Gleick Water in a World of Seven Billion, Calgary
What Does “Peak Water” Mean? • We’ll never “run out” of water overall. It is (mostly) renewable. • We will run up against renewable “flow” limits that are a combination of natural and economic constraints. • Where water is “non-renewable” we will run into stock constraints. • We are increasingly hitting (or exceeding) peak “ecological” water limits. • Hitting these limits has social, economic, and political implications.
Global Population Global CO2 Concentration
U.S. Oil Production Atlantic Cod 1950-2008
Market Penetration of Telephones Cumulative Dam Storage Capacity
Renewable or Non-Renewable? • Non-renewable resources are “stock” limited. • Renewable resources are “flow” limited. • Water and energy exhibit characteristics of both: but while most of our water use is renewable, most energy use is non-renewable.
Peak Renewable Water Total Renewable Supply But, how much can we actually use?? How much should we actually use? Gleick and Palaniappan 2010, PNAS
Total Colorado River Flow at the Delta Gleick and Palaniappan 2010
Global Reservoir Capacity 1900 to Present Source: GRanD Database v1.1, 2011
Peak Water? Continued exponential growth would have required new supply of approx. 850 cubic kilometers of water per year Source: P.H. Gleick 2011
Peak “Non-Renewable” Water Such as fossil groundwater (Central Valley, Ogallala, Libya, North China Plains, central India…) Gleick and Palaniappan 2010, PNAS
Bangkok Groundwater Pumping (Mm3/day) 0 0.4 0.8 1.2 1.6 2 2.4 2.8 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 2006 S. Buapeng 2009
Non-Renewable Groundwater Use: Ogallala Aquifer, US Source: USGS, Fischer et al. Open-File Report 99-197
Peak “Ecological” Water Overall Economic and Ecological Value Amount of Water Appropriated by Humans Gleick and Palaniappan 2010, PNAS
It is time for 21st Century Water Solutions • Efforts to design modern water policies are needed, and expanding: • Clarify institutional roles and responsibilities • Update water laws • Decentralize water management and increase stakeholder participation • Collect more comprehensive water data • Apply modern economic principles • Integrate changing climatic conditions • Move from a “supply” focus to a “demand” focus
Major Concepts/New Thinking “Soft Path” solutions for water • Rethink the concept of water “supply.” • Rethink the concept of water “demand.” • Protect water quality and match quality of supply to quality of need. • Use smarter economic tools. • Protect ecosystem needs and health. • Rethink water institutions, management, public participation, strategies.
Moving Forward on the Soft Path • Identify the Potential • Who is going to require water? • For what purpose or goal is water needed? • What kind of water? • How much water? • Identify Barriers to Sustainable Management • Behavioral • Technological • Information and data
Moving Forward on the Soft Path • Make Social Choices • Implement Diverse Options (“no silver bullet”) • Economic • Technological • Regulatory • Education
Traditional Sources of Supply Must be Supplemented with New Ones
Decadal Additions to Global Reservoir Capacity GRanD Data 2012
New Sources of Supply NEWater, Singapore (photo: P. Gleick 2011) GWRS, Orange County
Improve “Water-Use Productivity”We Can Produce More Food, Goods, and Services with Less Water[The use of water is a “means” not an “end.”]
What’s the first thing to do to a leaky bucket? $ $ $ $ $ $
The link between water use and economic growth can be broken GNP Water
Widespread efficiency improvements are possible, in all sectors • 1930s: 200 tons of water per ton of steel • 1980s: 20-30 tons of water per ton of steel • 2002: 2-3 tons of water per ton of steel (and we are changing the structure of our economy…) • Agricultural water use can drop and yields can increase with better irrigation technology.
New Thinking: We Can No Longer Ignore Climate Change • A hotter world. • Mixed changes in precipitation (both by region and time period). • Dramatic reductions in snowfall and accelerating snowmelt; related changes in runoff timing. • Rising sea-level with impacts on groundwater quality and coastal/delta ecosystems. • Accelerating influence on extreme events: including floods and droughts.
All extreme weather events are now subject to human influence.We are loading the dice and painting higher numbers on them.
New Thinking: The Human Right to Water Meet basic human needs for water and sanitation. UN General Assembly Resolution (July 2010) UN Human Rights Council (September 2010)
New Thinking: Integrate Ecosystems and Human Needs Instream flows, ecosystem flows, functional flows…. We need a better understanding of both the risks to humans from ecosystem degradation AND the benefits of maintaining ecosystem services.
New Thinking: Data, Information Systems Where are we? Where are we going?
We do not know how much water the world has. • We do not know, accurately, the key components of the hydrologic cycle or the world’s “water balance.” • We do not know how much water humans use. • We do not know how much water ecosystems need for minimal levels of health.
Some data collection is going the wrong way GRDC database on river discharge, 2011
And we have to be careful with the data we DO collect Goldilocks data principle • We have too much, • We have too little, • We have just the right amount (but we don't use it properly)
Groundwater Mapping from Space Groundwater changes in India, 2002-08. Losses in red and gains in blue. Based on GRACE satellite observations.
New Thinking: The Role of Population • Population stabilization is vital. There are important population-water feedbacks. • Expand access to water in schools --- girls stay in school longer --- more education leads to smaller family size. • Community involvement is essential for effective water management, especially involvement of women. • Expand education of women; expand education on water challenges
Final Thoughts • The water problem is real and bad – there are “peak water” limits and constraints. • There are human, economic, and environmental costs to inaction. • Not everything is getting worse. • New thinking is needed. What solutions are sustainable, scalable, and socially responsible? • New technologies • Better economics (water pricing, markets, subsidies) • Smarter, more integrated institutions • And new actions, commitments, and partnerships can move us in the right direction.
Dr. Peter H. Gleick pgleick@pipeline.com Oakland, California www.pacinst.org www.worldwater.org