Lecture 26-27Global Development lecture R PDF

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Professor: Elizabeth A Schultz ...

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12-09-08!

Although we have set aside a sizable area of parks and wilderness areas to preserve wild species and ecosystems—what will become of our own species!

How sustainable is our own life style? Can we manage the world well enough to keep ourselves from going extinct.!

Projections of the human population growth based on different birth and death rate assumptions.! http://ipmworld.umn.edu/chapters/ecology/unpop.gif!

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Most modellers are confortable with the assumption that the population will tend to follow the logistic model and level off to its carrying capacity (i.e. K)!

•  How comfortable should we be with this assumption?! ! • Malthus, 1798!

http://dieoff.org/Crash2.GIF!

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Population

The reindeer first depleted the most palatable lichens, which had the lowest rate of renewal! (high K, low r) ! ! • and gradually shifted to less and less desirable forage as the plant community changed.!

Islands were covered with lichens. - Reindeer eat all the liche and reproduce like crazy - The sustainable carrying capacity is now based on sedge rather than lichen which is much smaller. -Resource depletion scenario

the same pattern on St. Paul Island –also an island in the Bering Sea! http://www.mnforsustain.org/images/punctuation%20st%20paul%20isle%20diag%2011.jpg!

Odum points out in his 2nd edition of Fundamentals of Ecology! ! We can only reliably expect a population to approach a constant K if the renewability of its resources is sufficient to support it, and there is strong density dependent regulation. ! ! ! ! • no wolves on these islands and and preferred lichens very abundant but not rapidly renewable. ! • Reindeer reduced their own carrying capacity by shifting the plant communities away from preferred forage which couldnt sustain them.! • Less palatable heather-like forbs, sedges that remained was renewable enough to support the much lower population of reindeer.!

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Sequence of Resource Depletion

The whaling industry shifted to less profitable species as populations of overhunted species declined!

- Resource that was the most preferred or the mos valuable, were the first to be harvested (blue wha - As those population numbers decline, less desirable populations are then harvested - We assumed the whales population growth rates were higher than they we which meant populations would rapidly decline

Overgrazing has left many woodlands permanently scarred!

Goats are the last step in the sequence - They can eat just about anything, leaving the rangeland bare.

Grazing by goats has in many parts of the world completely removed ground level vegetation! - Once land has been stripped of its nutrients, the human population may lose the resource base it needs to support itself -Food shortages are already becoming a reality in some parts of the world.

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Similar depletion scenarios occur with soils, and without fallowing to allow soil nutrients and organic matter to rebuild soil use has become unsustainable in many parts of the world

There are huge sustainability issues regarding topsoil.!

Topsoil is being eroded much faster than new soil is forming.! ! How are new soils formed?!

Agriculture makes semi-arid landscapes unstable! !

Plowing the prairie contributed to massive wind erosion during prairie droughts!

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Irrigation has been practiced for thousands of years! Irrigation is not always sustainable Salt-damaged soils in Colorado!

- Have to consider how renewable the ground wat is. - The water used is rich in salts. The salt will then accumulate. Need to then grow salt tolerant crops. How sustainable is irrigation?! Consider the number of dams, wiers, wells, canals and dikes needed! Salt accumulation in surface soils! - Taxpayers- do not get anything Economics of irrigation: who pays/who benefits! out of it. Depletion groundwater quantity and quality!

- Hard to determine how depleted ground water aquifers are

Many states are supported by a huge underground aquifer Central Pivot irrigation system!

Since the late 60s, much of plains agriculture in the mid-western US is supported by groundwater! !

• Much of this is unsustainable! !

• Aquifers are declining and becoming polluted with fertilizer and pesticides!

- Much of the water is no longer suitable for agriculture

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- central pivot system - unknown level of sustainability

http://www.waterencyclopedia.com/images/wsci_03_img0398.jpg!

A great deal of hydrological research is being done to try to measure the rates of recharge and depletion of these major aquifers.!

http://geography.sierra.cc.ca.us/booth/California/3_hydrosphere/ogallala_aquifer.jpg!

http://www.unu.edu/unupress/unupbooks/uu14re/uu14re0k.jpg!

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Modern industrial farms are dependent on fertilizer input! • productivity is determined by the amount of N fertilizer used-fossil fuel dependent and unsustainable.! ! • Fertilizer use increased rapidly in the post war era.! !

• Modern agriculture exports most productivity and fertilizer input needs to balance export.! !

• Pre-industrially, most productivity consumed on the farm (animals and workers) and nutrients recycled as manure to maintain productivity. ! ! • Nutrient loss through crop export balanced by crop rotations using N-fixing plants to restore soil fertility.! !

Can Bio-technology feed us?! Surely we can do better than 1%!

Chlorella –a single-celled green alga which can renew itself every day!

Chlorella is being cultured en masse to feed people in Japan! • small nutrient rich cultures can approach 10% light capture, but in large scale culture, efficiency falls rapidly back to around 1%, unless a lot energy is invested into mixing.! • Why?!

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Global economics and trade leads to intercontinental species transfers!, which

can significantly degrade the productivity of the ecosystem In the 18th and 19th centuries most boat ballast was soil—so 1000s of plant and insect species were introduced to North America—these are still spreading and their impact is gradually being felt!

Purple loosestrife!

Zebra mussels! - Loss of native mussels - Damage to power system caused by the invasions o zebra mussels

- Invaded wetlands, and their ability to sustain waterfowl declines

- allow to regulate how full the boat is Modern pumps allow boats to use water ballast and now the stowaways are mainly aquatic—the aquatic communities of the Great Lakes has been dramatically altered.! !

Nearly half of the species that are listed as threatened are a result of the impact of exotic invaders.!

- sea lamprey got into the Great lakes destroying th salmon fishery

Native forests in New Zealand have nearly all been replaced by agricultural landscapes—nearly all european species.!

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Pollution of surface waters! - Degraded the productivity of surface waters Organic wastes create Biological Oxygen Demand—O2 depletion!

Oil spills!

In certain high traffic areas oil spills are so frequent that any hand full of sand from the beach feels oily!

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Disturbing the geosphere releases many toxic elements to the biosphere! Copper, zinc, cadmium, Selenium, Nickel, Chromium, Aluminum!

- Metals get released from geosphere during these disturbances. Most ecosystems cannot deal with these high concentrations of metals.

Mining and smelting are major geosphere disturbances.! - Reduce sustainable productivity of ecosystems

Geosphere disturbance releases significant quantities of mercury—! a volatile highly toxic metal that tends to accumulate in the atmosphere and come down in the rain and attached to dust!

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Cores from sediments of lakes and oceans show dramatic enrichment over the last 200 yr.!

• Many large wild piscivore are either inedible or require consumption advisories due to high mercury levels in their flesh!

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Enrichment of mercury in arctic sediment profiles!

Most mercury emissions are coming from the industrialized world! -- where mining, coal burning and smelting occurs the most! - Industrialized parts of the world produce the most mercury - Producing mercury way above sustainable levels

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What would the earth look like without life?! Copper Cliff, Tennessee—this area was once covered by a lush deciduous forest until acidic and metal-rich smelter fumes killed the entire vegetative community.!

Is the upper atmosphere sustainable?!

Ozone holes and CFCs—the Montreal Protocol!

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The CO2 content of the atmosphere has increased by 25% in 150 yr!

Text

Our emissions are so high we are using up 1million years of C accumulation every year.!

Fossil fuel! Coal!

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Planning for a sustainable future—Ecological economics!

Planning, management and conservation vs willy nilly exploitation!

Sustainability and the Ecological Footprint!

Mathis Wackernagel (1996)!

Ecological footprints measure the impact of a society on resources using a single metric—area of global biocapacity! !

How much farmland, area for waste disposal, productive ocean area, forest area, etc does it take to sustain a modern city?! ! When a populations footprint is larger than the biocapacity it has available it is judged to be unsustainable! Rees, W. and Wackernagel, M.:1996. Our Ecological Footprint. ! http://www.ew.govt.nz/enviroinfo/indicators/community/sustainability/ecofoot/images/report1.jpg!

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The Ecological Deficit! Consumption = Appropriated National Biocapacity + Imports - Exports

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Green—unused biocapacity! Red—overused capacity!

Countries have been stretched in proportion to their ecological deficit.! •  Global hectares is a measure of space normalized for productivity!

Assumptions behind EFA (Ecological Footprint Analysis)! ! • Possible to track resources consumed and wastes generated using official statistics! • Resource and waste flows can be converted into biologically productive area required to maintain these flows! • Bioproductive area available (biocapacity) can be scaled using productivity data for the area.! • Both consumption and capacity numbers can be added! • Deficit (Σ bioconsumption  Σ biocapacity) = unsustainability! •  The units for all calculations are global hectares!

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EFA- ecological footprint analysis

Problems with EFA analysis! ! At present EFA doesnt factor in:! • water ! • Contaminants! • Other species! • Over half of the earth has no data! • The global nature of the C cycle (C emissions counted against forest area)! ! However it represents the first crack at global sustainability analysis and new versions are coming out every few years. Eg.! ! ! van den Bergh, J.C.J.M. and Verbruggen, H.: 1999, Spatial sustainability, trade and indicators: an evaluation of the ecological footprint,Ecological Economics 29(1), 61-72. !

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EFA is the first serious attempt at sustainability analysis of the global economy, and it is based on a combination of ecological and economic principles! ! !

Journal ! Ecological Economics!

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Managing access to renewable resources—eg groundwater and fisheries!

Cost-benefit curve for a fishery Tangent

Total Costs

Benefits & costs of fishing effort, $

Benefits

0

Eeff

Emsy

Ec

Fishing effort (units)

This analysis involves assumptions that simplify it without sacrificing too much realism! ! 1.) Benefits depend on the amount of fish caught times a price assumed to be constant.! ! 2.)The Cost of each additional unit of fishing effort is constant.! ! ! (Thus the benefit curve looks like the reverse of the fish renewability curve, and the cost function is a straight line)!

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"Too many people, in too many boats, chasing too few fish".! !The problem of open-access fisheries! ! !

• in a fishery the most efficient allocation of effort (maximum net benefit) requires an effort level well below that required to obtain the MSY.! • This effort level would be both ecologically sustainable and economically efficient! • Many owner-operated fisheries, both recreational and commercial do seem to operate in this manner.! • Most open-access fisheries do not operate efficiently and often not sustainably either.! • Most suffer from over-capitalization (too much effort), leading to stock collapse, and socio-economic hardship!

What can be done about the overcapitalization problem in openaccess fisheries?! ! 1.)Aquaculture or ranching of wild fish!   g! ood for shellfish, salmon, catfish, trout,!   d! oesn't work for tuna, cod, percids!   t!akes up a lot of space, and causes significant environmental !damage! 2.)Raising the costs, use less efficient gear or methods! !

3.)Taxes on fishing permits! !

4.)Individual Transferable Quotas (ITQs)! !

5.)Small-scale co-operatives and sea-tenure system! !

6.)Eliminate government subsidies!

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Natural Ecosystem Goods & Service Global valuation! ! • Air Purification ! ! • Climate Stabilization ! • Spawning&nursery! • Habitat for fish etc ! • Drought,Erosion&Flood! • Control&Coastal protection • Soil renewal and nutrient cycling • Pollutant Assimilation ! • Pollination ! ! • Natural pest control ! • Aesthetics &recreation ! • Biodiversity (genetic resources) • Fish, Lumber etc ! • Water supply & purification

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!$1.3T/yr! !$0.6T!

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! $0.1T !

! ! ! ! ! ! ! ! !

! !$17T ! ! ! ! ! !$0.1T ! ! !

!$3.5T!

Total ! ! Costanza et al (1996), Nature!

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!$2.3T ! !$0.1T! !$0.4T! !$3.8T ! !$2.0T! !$1.7T! !$33.2T!

- More than double the global GDP

Investing in the Biosphere! ! Economic productivity depends a great deal on natural capital, which is being rapidly depleted due to overuse and mismanagement.! ! Is it better to invest in maintaining ecosystem services that function naturally, or is it better to invest in substitutes that provide the service but in a different way?! ! We will have a look at this question within the context of "Water Purification"!

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Chichilnisky and Heal, 1998, Nature!

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Securing a sustainable water supply for New York City! ! • The Catskill mountains, which constitutes the watershed from which the city water supply is drawn, is being gradually overdeveloped to an extent that puts the future water supply at risk.! • The city would need to invest between 1-1.5 billion$ to essentially buy up the watershed and limit development. ! • The alternative was 6-8 billion $ in water purification plants on the Hudson river, which flows through the city.! • The city has chosen to invest in the watershed—bond issue ! • In Canada many cites face similar choices.!

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http://www.catskillaccommodations.com/maps/images/ny100b.gif!

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The water supply for the - Makes more sense to Toronto and surrounding protect these areas suburbs all comes from the Oak Ridges moraine! which is at under heavy pressure from developers.!

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Lost fertility—the heavy footprint of history! Man and Nature—George Perkins Marsh, (1864)! Collapse—Jared Diamond (2005)!

A viking ship salvaged from the bottom of - Viking ships allowed the the Baltic Sea! !

vikings to travel and trade

Viking Ship Museum, Roskilde, Denmark! - 2 weeks to make a vikin

To build a Viking ship required several several very large oak trees.!

ship - Oak tree takes 500 years to make - As soon as they ran out of trees to make the boats their system failed

http://www.astro.uu.se/~hoefner/sail/pics/viking2.jpg!

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