Name : Emily Guo
Student # : 20379264 ---------------------------------------------------------------------------------------------
November 6th.
WATER.
Supply :
- covers 70.9% of Earth's surface
- 97% is salt water > unusable
- 2% are ice bergs, glaciers, ice caps
- 1% is usable fresh water - fresh water needed for drinking, eating, processing etc.
- portion of 1% unusable because it's impossible to obtain (under water reservoirs) - .33% (1/3) of Earth's water is USABLE
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- majority of water consumption used to produce food (in modern society)
- growth of world's population rapid, upgrades in systems needed to keep up
- 1000 gallons of water per pound of food per person (U.S.A) (growth and process)
- 1500 pounds of food per year per average person = 1.5 million gallons of water per year - animal products > plant products in water usage
- water used to cool machinery down (energy?)
- machinery for transportation, conditioning, cooking, shipping
- 70% of global water withdrawals used in farming
- expected to increase 14-17% in next 20 years
- water used in irrigation, soil
Conservation :
- food production industry must improve water productivity and quality
- minimize amount of water needed to produce food - recycling waste water, drip irrigation, water storage and minimized tilling
Altchison, Christin. "Water Use in Food Production: Food Consumption Effects the World Water Supply." September 26, 2008.http://www.suite101.com/content/water-use-in-
food-production-a70476 (accessed Novemver 6, 2010).
November 7.
- 60-watt lightbulb lit for 12 hours uses as much as 60 litres of water
- fossil-fuel-fired thermoelectric power plants consume more than 500 billion L of fresh water / day (U.S.A) (Virginia Water Resources Research Center)
- average 95 L per 1 kilowatt-hour of electricity
- water in energy production: pumping crude out of the group, removing pollutants from power plant exhaust, generating steam that turns turbines, flushing away residue after fossil fuels are burned, keeping power plants cool
Natural gas (fuel of choice) :
- 38 L of water per 1000 kWh* of electricity
- water used to extract enough natural gas - produces most energy per unit volume of water consumed
Coal-fired power plant :
- 530 L of water per 1000 kWh of electricity
Biodiesel :
- more than 180 000 L of water to produce enough soybean-based biodieseal to keep lights on for one day in 1000 homes - water needed to irrigate soil and turning soybeans into fuel etc. *L/1000 kWh = amount of energy required to power 1000 homes in U.S.A for one day
Jones, Willie D.. "IEEE Spectrum: How Much Water Does It Take to Make Electricity."
April 2008.http://spectrum.ieee.org/energy/environment/how-much-
water-does-it-take-to-make-electricity (accessed November 7, 2010)
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November 9
Global Water Crisis
- water's earth's most valuable resource
- all ecosystems and humans depend on water
- no substitute for water
Global Energy Crisis
- world energy system depends largely on finite fossil and nuclear energy sources
- require long resource chains
- energy system causes environmental effects
"Energy and Water, The Ignored Link," The Coming Global Oil Crisis, accessed November 9, 2010, http://www.oilcrisis.com/waterways/
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The wars of the twenty-first century will be fought over water.
- Ismail Serageldin, World Bank Vice President for Environmental Affairs
We used to think that energy and water would be the critical issues for the next century. Now we think water will be the critical issue.
- Mostafa Tolba, former head of the United Nations Environment Program
- global water supply drop 33% since 1970
- water heavily subsidized commodity, costing roughly $1 per 1000 gallons
2 issues with water :
- getting it there
- making it clean enough
- 55 billion gallons of water per person on planet
Israel success @ recycling 70% of their water
- provides 35% of drinking supply from sea water
California @ recycling 1-2%
Water-Energy Nexus
"If we could ever competitively, at a cheap rate, get fresh water from saltwater, ..(this) would be in the long-range interests of humanity which could really dwarf any other scientific accomplishments."
- John F. Kennedy
- most water in US 980%) delivered through public agencies
- water delivery major energy user (19% of total consumption in California)
- est. thing 25 years, 2/3 of world will live in countries with water problems
- increased water demand = higher energy demand
"Water: The New Energy Crisis?" The Huffington Post, accessed November 9, 2010, http://www.huffingtonpost.com/paige-donner/water-the-new-energy-cris_b_91574.html
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- key to avoiding a global food crisis > storing more water
- climate change = weather harder to predict/prepare for, traditional sources of irrigation water much less reliable
- leads to problems for feeding population esp. African, Asian farmers rely on rainwater for crops
ASIA
- 66% of cropland is rain-fed
sub-SAHARAN AFRICA
- 94% of farmland relies on rain
- existing water storage equal to less than 26,400 gallons / person COMPARED 1.3 million gallons / person (2 Olympic-sze swimming pools)
Diversity and Insure
- Adapt?
- fund diversity of water storage projects
- small-scale rainwater tanks, larger scale dams.. to systems that artificially recharge groundwater aquifers > improve soil to hold more water
- use stored water as insurance against climate change, climate variability
- stored water in times of drought make difference between chronic hunger/steady progress toward food secuirity
Large-Scale Dams
- need to feed/provide electricity
- associated with significant environmental change
"How to Stem a Global Food Crisis? Store More Water," National Geographic, accessed November 9, 2010,
http://news.nationalgeographic.com/news/2010/09/100907-food-crisis-water-storage-climate-change/
BY EMILY GUO.
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