Freshwater Sustainability

Thomas M. ParrisApril 3, 2008parris@isciences.com

http://www.isciences.com http://www.terraviva.net

Global Distribution of the World’s Water

• Freshwater is precious!

• Freshwater is 2.5% of total

• ~30.5% of freshwater is renewable (non-fossil groundwater, surface water)

Source: UNEP (2007). Global Environmental Outlook 4: Environment for development. Progress Press Ltd.: Malta

Terrestrial Hydrologic System

Source: Falkenmark M, Lannerstad M (2005). “Consumptive water use to feed humanity – curing a blind spot.” Hydrology and Earth System Sciences 9:15-28.

Total Freshwater Withdrawals and Consumptive Use (1900-2050)

0

1000

2000

3000

4000

5000

6000

1880 1900 1920 1940 1960 1980 2000 2020 2040

Year

km3/

year

Total Withdrawals Consumptive Use

Assessment Forecast

Growing Demand for Freshwater

Source: Shiklomanov IA (1998). “Assessment of water resource and water availability in the world.” Report for the Comprehensive Assessment of the Freshwater Resources of the World, United Nations. As reprinted in Gleick PG (2000). The World’s Water 2000-2001. Island Press: Washington, DC.

Freshwater Withdrawals & Consumptive Use by Sector

Percentage of Total Withdrawals by Sector (1900-2025)

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

1900 1940 1950 1960 1970 1980 1990 1995 2000 2010 2025

Year

% T

ota

l W

ith

dra

wa

ls

ResevoirWithdrawals

HouseholdWithdrawals

IndustrialWithdrawals

AgriculturalWithdrawals

% Consumptive Use by Sector

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

1900 1940 1950 1960 1970 1980 1990 1995 2000 2010 2025

Year

% C

on

su

mp

tiv

e U

se

ResevoirsConsumptiveUse

HouseholdConsumptiveUse

IndustrialConsumptiveUse

AgriculturalConsumptiveUse

Source: Shiklomanov IA (1998). “Assessment of water resource and water availability in the world.” Report for the Comprehensive Assessment of the Freshwater Resources of the World, United Nations. As reprinted in Gleick PG (2000). The World’s Water 2000-2001. Island Press: Washington, DC.

Agriculture and Water

In 35 years post WWII world agricultural production doubled by increasing:nitrogen fertilization by factor of 6.9phosphorous fertilization by factor of 3.5cropland under irrigation by factor of 1.7Land under cultivation by 1.1

Source: Tilman D (1999). “Global environmental impacts of agricultural expansion: The need for sustainable and efficient practices.” Proceedings of the National Academy of Sciences of the United States of America 96:5995-6000 (May).

Agriculture and Water (cont.)

If the same methods are used, the next production doubling is optimistically estimated to require:3x more nitrogen3x more phosphorous2x more irrigated land area1.18 x more land under cultivation

Source: Tilman D (1999). “Global environmental impacts of agricultural expansion: The need for sustainable and efficient practices.” Proceedings of the National Academy of Sciences of the United States of America 96:5995-6000 (May).

Agriculture and Water (cont) “The global agricultural enterprise is passing a

threshold.

It has gone from being a minor source of off-site environmental degradation 35 years ago to becoming the major source of nitrogen and phosphorus loading to terrestrial, freshwater, and marine ecosystems.

If this loading increases as projected here, agriculture will adversely transform most of the remaining natural, nonagricultural ecosystems of the world.

Because the global environmental impact of agriculture on natural ecosystems and the services they provide may be as serious a problem as global climate change, the impacts of agriculture merit more study.”

Source: Tilman D (1999). “Global environmental impacts of agricultural expansion: The need for sustainable and efficient practices.” Proceedings of the National Academy of Sciences of the United States of America 96:5995-6000 (May).

Measuring Water Stress

Water Availability per capita

Water Withdrawal Ratio

Water Reuse Index

Analysis By Country

Source: UN World Water Development Report: Water for People, Water for Life, UNESCO, 2003

Source: Pilot Analysis of Freshwater Ecosystems: Freshwater Systems, World Resources Institute, 2000

Water Withdrawal Ratio

Source: Water Systems Analysis Group. Indicators for World Water Assessment Programme. http://wwdrii.sr.unh.edu/

Water Reuse Index

Source: Water Systems Analysis Group. Indicators for World Water Assessment Programme. http://wwdrii.sr.unh.edu/

Corporate Social Responsibility Reporting Global reporting initiative (www.globalreporting.org)

establishes standard metrics for corporate social responsibility reports

Water metrics include Total water withdrawal by source Water sources significantly affected by withdrawal of water Percentage and total volume of water recycled and reused Total water discharge by quality and destination Identify, size, protected status, and biodiversity value of water

bodies and related habitats significantly affected by discharges of water and runoff

Global Water Tool

World Business Council on Sustainable Development (WBCSD) http://www.wbcsd.org/web/watertool.htm

Excel-based spreadsheet to help companies produce GRI water related metrics Accounting Map lookups

access to improved water (country-by-country), access to improved sanitation (country-by-country), annual renewable water supply per person 1995 (major

watershed-by-major watershed), annual renewable water supply per person 2025 (major

watershed-by-major watershed), Water withdrawal ratio (0.5° x 0.5° grid cells), or the Ratio of industrial to total water use (0.5° x 0.5° grid cells).

Time Horizon

Chronic Conditions Expected conditions using current climate and typical use

Episodic Conditions Today’s conditions using current weather and today’s use

Long-Term Conditions Future chronic conditions using scenarios of future

climate and future use Frequencies of future episodic conditions using scenarios

of future climate and future use

Types of Drought

Meteorological droughts occur when precipitation and temperature depart significantly from norms derived from long-term observations

Hydrologic droughts occur when accessible blue water and subsurface supplies depart significantly from long-term norms derived from long-term observations. Hydrologic drought addresses changes precipitation in the context of hydrologic transfers through rivers, lakes, subsurface geology, and other inland aquatic systems.

Agricultural droughts occur when accessible blue water and subsurface supplies are insufficient to support normal rain fed crop or rangeland production

Socio-economic droughts occur when accessible blue water and subsurface supplies are insufficient to support normal freshwater withdrawals in aggregate

Global Drought Monitor

12 Month Precipitation Drought (April 2008) 12 Month Soil Moisture Drought (April 2008)

Source: Global Drought Monitor, http://drought.mssl.ucl.ac.uk/

Selected GCM Runoff Estimates (1989-1999)

GISS AOM 4x3 CCSM3

CM 2.1 UNH/GDRC Composite Fields

Sources: ISciences, Goddard Institute of Space Science (NASA) Sources: ISciences, National Center for Atmospheric Research (NCAR)

Sources: ISciences, Geophysical Fluid Dynamics Laboratory (NOAA) Sources: ISciences, University of New Hampshire - Global Runoff Data Center