Global Environmental GovernanceJames Gustave Speth and Peter M. Haas

Speth and Haas: Ten of the major global environmental challenges are:

1. Acid rain and regional air pollution

2. Ozone depletion

3. Climate disruption [global climate change]

4. Deforestation

5. Land degradation and desertification

6. Freshwater degradation and shortages

7. Marine fisheries decline

8. Toxic pollutants

9. Loss of biological diversity

10. Excess nitrogen

Acid Rain

EPA

Acid Rain

• Effects• Terrestrial• Leaches minerals (nutrients, metals) from soil

• Facilitates desertification

• Damages leaves of plants• Aquatic• Irritates gills of aquatic organisms

• Interferes with gas exchange

• Erodes slime layer of fishes• Reduces resistance to pathogens

• Erodes shells of aquatic mollusks and arthropods• Impedes ability of crustaceans to recalcify after molting

• Facilitates release of toxins bound to particles in sediments

Lu et al. 2010

Lu et al. 2010

Air Pollution – Components

• EPA – NAAQS for six criteria pollutants• Particulate matter

• PM2.5, PM10

• Carbon monoxide (CO)• Nitrogen oxides (NOx)

• Sulfur oxides (SOx)

• Ground-level ozone (O3)

• Lead (Pb)

Piccadilly Circus, Dec. 1952

Matus et al. 2012

PM10 Concentrations, 2005

Red Line: US NAAQS, pre-2006

Air Quality (Tropospheric NO2)

Summer 2006

http://www.nybg.org/bsci/res/bahia/Defor.html

1945 1960 1974 1990

Bahia

Tropical Forest Loss

• Four major types1) Tropical rain forests

• More than half in Brazil (41%) and Indonesia (13%)2) Moist deciduous forests

• Usually less diverse than rain forests3) Dry zone forests

• More than 50% in Africa4) Tropical upland forests

• Includes cloud forests• Current Status

• Not all tropical rain forests are the same or under the same pressures

• Worldwide – ~66% cleared for agriculture• Africa – Population growth & subsistence farming• Asia – Logging; subsistence farming increasing• Latin America – Ranching; subsistence farming

increasing

Tropical Forest Loss

Region Land Area

Forest 1980

Forest 1990

Area Change

Annual % Loss

(million ha)

Africa 2236 568 527 -41 0.7%

Asia 892 350 311 -39 1.2%

Latin America

1650 992 918 -74 0.8%

World 4778 1910 1756 -154 0.8%

http://www.fao.org/docrep/t4450e/T4450E0k.htm

Fresh Water

• Historically limiting factor in arid regions• 1940-1990

• World population more than doubled • 2.3 billion 5.3 billion

• Per capita water use doubled• 400 m3 person-1 year-1 800 m3 person-1 year-1

• Global water use increased fourfold• 2000: USA ~2000 m3 person-1 year-1 (~1450 gal day-1)

A. Current Status• In 1996, world human population using estimated 54%

of all accessible fresh water in rivers, lakes, aquifers• Many people predict disastrous consequences for

world’s fresh water supply in coming years• This potential disaster may have several causes

Fresh Water

• Current Status1. Distribution

• Uneven compared to population• 75% of annual rainfall in areas containing less than

one-third of global population• Amazon River carries 20% of global runoff through

area containing 10 million people• Congo River carries 30% of Africa’s runoff through

area containing 10% of population• Uneven in space

• North America contains 19,000 m3 per person per year vs. 4700 m3 per person per year in Asia

• <10% of Mexico supplies >50% of annual runoff• Uneven in time

• India gets 90% of annual rainfall during summer monsoon season (Jun-Sep); runs off too rapidly for efficient use

Fresh Water

• Current Status2. Usage patterns

• Agriculture – 69%• Industry/Energy – 23%• Domestic – 8%• Varies among regions and with development

• Africa – 88% for agriculture (irrigation)• Europe – >50% for industry• Japan – Industrial but uses lots of water to grow rice

• Personal use tracks standard of living• Africa – 17 m3 year-1 (12.3 gal d-1)• Asia – 31 m3 year-1 (22.4 gal d-1)• UK – 122 m3 year-1 (88.3 gal d-1)• US – 211 m3 year-1 (153 gal d-1)

• By 2020, water shortages likely in Ethiopia, India, Kenya, Nigeria, China (parts of China already face problems)

Fresh Water

• Possible Solutions• World may have enough fresh water but

inadequate distribution mechanism• Long pipelines and movement of icebergs

have been proposed• Excessively expensive• Technological limitations

Fresh Water

• Possible Solutions1. Improved irrigation efficiency

• Drip irrigation reduces losses from evaporation• Cuts water use by 40-60% compared to conventional

systems• Used on <1% of irrigated land worldwide but used

extensively in some countries• Ex: Israel uses DI on 50% of irrigated land

2. Municipal conservation• Infrastructural losses can be substantial

• Ex: 40-70% of water lost in transit in 15 major Mexican cities (similar rates in India)

• Ex: Djakarta, Indonesia could cut water losses an estimated 20% by fixing leaky distribution pipes; would save ~12 billion gallons of water a year, enough to supply 800,000 people

• Higher price could encourage conservation• Ex: Bogor, Indonesia increased water prices 3-4x;

average household water use dropped by 30% in less than one year

Fresh Water

• Possible Solutions3. Reuse of urban wastewater

• Use of treated wastewater for irrigation• Today, at least half a million hectares in 15 countries are

being irrigated with “gray water”

4. More water-efficient industry• Practiced in industrialized nations.• Amount of water needed to produce a ton of steel ranges

from 23 to 56 m3 in China, compared to an average of less than 6 m3 in US, Japan, and Germany

5. Desalination• 2010: Over 20 billion gallons of fresh water produced

daily in ~15,000 facilities worldwide• Minimum cost = 0.2¢ gal-1

• Current methods of desalination driven almost entirely by combustion of fossil fuels

• Solar powered desalination plants produced only 1.4 million gal d-1 in 2009

USA Today

Stratospheric Ozone Depletion

• Industrial processes release halocarbons and other gases into the atmosphere, reacting with ozone and destroying the ozone layer

• More pronounced in colder Antarctic than Arctic• Reduced protection from harmful ultraviolet

radiation• Ozone normally reacts with uv light but is

regenerated• O3 + uv light O2 + O

• In presence of HCs and other compounds that contain Cl

• O3 + Cl O2 + ClO

Deforestation

• Less than 20% of original forest cover remains in many countries

• Philippines, Madagascar

• Loss of CO2 uptake capacity

• Biomass burning• Decomposition of organic material• Increased erosion/nutrient loss

Water Pollution – Nutrients

• Nitrogen, phosphorus• Common sources

1) Crop and lawn fertilizers2) Manure3) Sewage4) Detergents containing phosphates and nitrates

• Excessive nutrient loading eutrophication• Effects

1) Plant growth can clog waterways (ecology, navigation)2) Plants can interfere with recreation (swimming, boating)3) Nighttime oxygen depletion4) Nitrate methemoglobinemia (blue baby syndrome)

• Nutrients can be difficult to control once in a system• Recycling and regeneration

• Eutrophied water bodies can recover if sources are removed

• Ex – Lake Washington

Kiely 1997 Environmental Engineering