EIAs
· They most include a section that identifies the impact.
· Try to predict or to estimate the value or reach of this impact.
· Assess or limit an impact.
History of EIAs
In 1969 National Environment Policy Act adopted by other countries in order to access environmental resources as wealth and with the same importance as economic and other resources.
Economic resources
An economic system produces and distributes goods and services by using natural, human, and manufactured resources, in order to satisfy people’s needs and wants (in the most efficient and effective way) Such as the capitalist and communist systems and the ejidos.
Resources
· Might be known as capital
· Capital used as or to produce goods and services.
· Three types
o Natural capital
§ Includes natural resources that have value and that support life.
· Trees, soil, water, living organism, ores, etc.
· Flood and erosion protection by forests, etc.
§ Natural capital may also be processes.
· Photosynthesis.
· Water and gas cycles.
o Natural capital in economic systems:
§ Capital yields income.
§ Natural capital yields natural income.
§ The World Bank now calculates wealth of countries by including the rate of extraction of natural resources and the ecological damage caused by this.
§ Sustainability often represents sources of conflict within and between political parties and countries.
§ Yield of services.
· Water cycle provides fresh water.
· Photosynthesis provides oxygen.
§ Natural Capital/Natural Income = Resources/Yields
§ Three main categories:
· Renewable: Can replace r restock themselves, have solar energy as it source.
o Water
o Lumber
· Non renewable: Exist in finite amounts on Earth and cannot be replaced after being depleted, also they represent short term solutions.
o Fossil Fuels
o Minerals and metals
· Replenishable: Middle ground between the two above, are replaceable over a long enough period of time that they are not renewable but not enough to be non-renewable. The difference between this and renewable is the rate of resource use and rate of resource replacement.
o Groundwater
· Recyclable resources: Resources that can be transformed into usable materials after already being used form something else. Should only be an option if you don’t longer have that resource.
o Iron
o Aluminum.
§ What is sustainability?
· It means to live between the means of nature, in the sustainable natural income generated by natural capital. Any society that supports itself in part by depleting essential forms of natural capital s unsustainable. Economists and environmentalists may have very different points of view on what is sustainable.
o Human capital:
§ Workforce
o Manufactured capital
§ Machinery
§ Fuels
Chapter 24
· Economic growth: the increase in a nation’s capacity to provide goods and services.
· Economic development: the increase in human development that derive from economic growth.
· Neoclassical economists: believe natural capital as important that not indispensible since we will find a substitute for them. (Friedman and Samuelson) Utilitarianism.
· Ecological economists: they are no substitutes for many natural resources and that economic growth will deplete natural capital and pollution will surpass the environment’s capacity to handle them. They want to redesign our economic and political systems to encourage sustainable forms of economic development. (Costanza and Daly)
· Environmental economists: They agree with ecological economists but believe that we don’t need to redesign the economic systems but rather reform them to have a more sustainable system.
· In my book, sustainability is a condition where people live their lives in an environmentally sound manner and in a state of social justice and environmental integrity just as to no compromise the ability of other human beings to live the same way in the future.
· Sustainable yield can be seen as the increase of natural capital. The natural income that can be exploited each year without depleting the original stick or its potential for replenishment.
o Carrying capacity
o Population size
o Total biomass
o Rates of change of population/biomass/energy
o SY=(total biomass or energy at a given time+1) – (Total biomass or energy at a Time+0)
o SY= Annual growth and recruitment – annual death and emigration.
· Dynamic nature of a resource
o The importance and/or value changes over time
o The availability changes over time
· Resources can be valued in different ways
o Economic =marketable goods
o Ecological=Life support systems
o Scientific=
o Intrinsically=cultural
· The measure of true wealth of a country includes its natural capital.
· In other words, how many resources, forests, rivers it has.
· In general, MEDC’s add value to natural income by manufacturing goods from it.
· LEDC’s may have greater unprocessed natural capital.
· World Bank calculates a country’s wealth by including the rate of extraction of natural resources.
Human Population Dynamics
· Populations can change over time due to many factos
o Density dependent factors: They are modified due to the size of the population
§ Biotic factors
§ Negative feedback mechanisms to regulate and stabilize the population size.
· Internal: act within a species. Ex. Limited food supply and density dependent fertility
· External: act between species, predation and disease.
o Density independent factors: These are present and not modified due to population’s size.
§ Abiotic factors
§ Effects aren’t related to population’s density
§ Acts of God such as weather, climate, volcanic eruptions, floods.
§ Not part of a feedback system.
· Population patterns
o S-curves
§ Start with exponential growth.
§ Then above a certain population size, the growth rate slows down until the size stabilizes.
§ Consistent with density limiting factors.
§ It stabilizes at the carrying capacity of the environment.
§ Area between exponential growth curve and S-curve is called environmental resistance.
§ Phases:
· Lag phase: slowly
· Exponential phase: exponential growth
· Deceleration phase: it slows again
· Stationary phase: stabilization around carrying capacity.
· Overshoot: when after the deceleration phase, the population surpasses the capacity.
· Die-back: when the population decreases to the carrying capacity level.
o J-curves:
§ Shows a boom and bust pattern.
§ Population grows exponentially then crashes.
§ These collapses are called diebacks.
§ Population often exceeds K before the collapse occurs which is referred to as overshoot.
§ Typical of microbes, invertebrates, fish, and small mammals.
· Population strategies:
o K-Strategies:
§ Long lifespan
o R-strategists:
§ Short lifespan
· Population Changes
o Main factors
§ Birth Rate
§ Death Rate
§ Immigration
§ Emigration
o Measures of population change
§ Crude birth rate: Number of births per 1000 individuals. Dividing the number of births by population size
§ Crude death rate: doesn’t includes anything else but # of dead and # of births. Number of deaths per 1000 individuals. Dividing the number of deaths by population size.
§ Doubling rate: How fast a particular population doubles its amount. Doubling time=70/NIR
§ Natural Increase rate: NIR=(CBR-CDR)/10. Doesn’t considers immigration/emigration.
§ Total fertility rate: the average number of children that each woman has over her lifetime, it shows the potential for population change.
· TFR=2.0 population is stable.
· TFR < 2.0 population decrease.
· TFR >2.0 population increase
· Human population:
o The industrial revolution and the appearance of some medicines changed the human population curves.
o Human development index: measure of the “well-being” of a country. It combines measurements of life expectancy, standards of living, education, and GDP per capita into one index.
o MEDCs
§ Industrialized nations with high GDPs, they have relatively rich population and starvation is unlikely. High level of resource use per capita. Relatively low population growth rates.
o LEDCs
§ are less industrialized, plenty of natural capital, lower GDP and high property rates, large population sector and high population growth rate.
o Population size is not the only factor that determines our species’ impact.
§ Amount of wealth and distribution.
§ Resources desire
§ Resource need
o Population Growth and Food Shortages:
§ Thomas Malthus: clergyman and economists he wrote a theory of competition of resources that influenced Charles Darwin and many others.
·
· That the power of population is indefinitely greater than the power in the earth to produce subsistence for man.
· Population growth will outpace agricultural production.
· According to Malthus, disease, food shortage and death due to starvation, were nature's way to control population.
· He thinks the control of birth will prevent these problems.
· It assumes population grows exponentially and agricultural production grows in a linear manner.
· It doesn’t recognizes human capacity to increase food supply.
§ Ester Boserup: was a Danish economist and writer who worked for the UN, she wrote about population growth and agricultural development from a technocentric perspective.
· Humans will create technology to increase the food supply and create a sustainable society.
· Necessity is the mother of invention.
o Future World Population
§ If the fertility rate is 2.0, the population will stabilize a bit and rise to 10.8 billion by 2050.
§ If every second woman has 3 instead of 2 children, population will rise to 27 billion by 2150. However if instead every second woman has just 1 child, then population will drop to 3.6 billion.
§ Currently TFR is about 3.0
o Why Have So Many Kids?
§ Does not seem to be correlated with GNP nor personal wealth.
· High mortality rates for infants and youth.
· Security in old age.
· Children are an economic asset in agricultural societies.
· Status of women
o Only considered worthy only for making children and their social status depends on the number, especially boys.
o Education has allowed women to gain status outside of the context of mere baby factories and has contributed toward low fertility rates of MEDC’s.
o Unavailability of contraception: All measures that avoid or suspend pregnancy.
§ Reduce birth rate:
· Promote alternative “family models”, adoption, etc.
· Provide Education
· Make contraception available.
· Improve health availability.
· Standards of living.
· Nutrition
· Better economic conditions
· Resources distribution
Many environmental impact models are based on the assumption that all individuals in a population have the same resource use and waste profile and thus impact the environment equally
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