Unit 1 - Foundations of Environmental Systems and Societies (copy) (copy)

what are the categories of EVS?

ecocentrics, anthropocentrics, technocentrics

What is the ecocentric world view?

• puts ecology and nature as central to humanity

• life-centered, respects the rights of nature and dependence of humans on nature

• less materialistic approach to life

• self-restraint

• self sufficiency in human societies

ecocentric categories

deep ecologists, self reliant soft ecologists

What is the anthropocentric world view?

believes humans must sustainably manage the global system (through use of taxes, environmental regulation); human centered - humans are not dependent on nature but nature is there to benifit human kind

What is the technocentric world view?

• believes that technological developments can provide solutions to environmental problems

technocentric categories

technocentrics, cornucopians

cornucopians

• believe world has infinite resources

• through technology humans can solve any environmental problems + improve living standards

• free market economy

environmental managers

• believe humans have ethical duty to protect the earth

• believe that governments need to protect environment, and make sustainable economies

deep ecologists

• put more value on nature than humanity

• believe in biorights - all societies and ecosystems have an inherent value and humans have no right to interfere

types of systems

closed system, open system, isolated system

open system

exchanges matter and energy with its surroundings

closed system

exchanges energy but not matter, do not occur naturally on earth, however earth is a closed system

isolated system

does not exchange matter or energy, no such systems exist, however cosmos could be an isolated system

what does the biosphere consist of?

atmosphere, lithosphere, hydrosphere, ecosphere

all systems have …

• storages

• flows

• inputs

• outputs

• boundaries

• processes

what is an energy transfer?

when the flow of energy or matter flows and changes location but not its state

what is an energy transformation?

when energy or matter flows and changes its state

types of energy transformations

• chemical to mechanical

• radiant to chemical

• electrical to thermal

Energy in systems rely on…

the laws of thermodynamics

First law of thermodynamics

energy is neither created nor destroyed, therefore energy is constant (in any type of system), and can only be altered in form (through transfers and transformations)

Second law of thermodynamics

entropy of a system will tend to increase over time

entropy

spreading out or dispersal of energy

nature of equilibria

• steady state equilibrium

• static equilibrium

efficiency

defined as useful energy

efficiency formula (2)

• efficiency = energy produced / energy consumed x 100%

• efficiency = useful output / input x 100%

equilibrium definition

the tendency for a system to return to an original state following a disturbance

Steady state equilibrium characteristics

• applies to open systems

• more or less constant

• no long term changes

• system will return to its previous state

• continuous inputs and outputs of energy and matter

Static equilibrium characteristics

• no change over time

• stable

• when disturbed, creates new equilibrium

• non living systems

negative feedback

• returns system to its original state

• same state of equilibrium

• stabilising as they reduce change

positive feedback

• changes system to a new state

• new state of equilibrium

• destabilizing as they increase change

stable equilibrium

tends to return to the same equilibrium after a disturbance

unstable equilibrium

system returns to a new equilibrium after disturbance

resilience of systems

measures how a system responds to a disturbance

the more resilience …

the more disturbance the system can deal with, keep the same state

the less resilience …

the less disturbance the system can deal with, will enter a new state

factors affecting ecosystem resilience (7)

more complex system, more resilience, as there are more interactions between species ; the greater the species the greater the chance that a species can replace another if one dies out ; the greater the genetic diversity within species, the greater the resilience ; species that can shift geographical ranges are more resilient ; the larger the ecosystem the more resilience ; climate affects resilience ; faster reproduction means faster recovery

tipping points

the minimum amount of change within a system that will destabalize it, causing it to reach a new state

characteristics of tipping points

• involve positive feedback

• threshold point cannot be precisely predicted

• the changes are long lasting

• the chances are hard to reverse

• there is a time difference between the pressures driving the change and appearance of impacts

sustainability definition

Using global resources at a rate that allows natural regeneration and minimizes damage to the environment

natural capital

goods and services provided by nature

natural income

yield obtained from the use of natural resources

renewable natural capital

resources that are able to replace themselves by growing

replenishable natural capital

between renewable and non-renewable resources

non-renewable capital

resources that are finite, once consumed not replaced

Values of natural income

economic, ecological, scientific/technological, Intrinsic value (cultural or spiritual)

Max Sustainable Yield (MSY)

max amount of harvest that can be extracted from a renewable resource without negatively impacting the reference population size in the future

Sustainable Yield (SY)

annual gain in biomass or energy through growth and recruitment (without depletion of natural stock)

Formula SY

• total biomass / energy (at time t+1)

• total biomass / energy (at time t)

• annual growth and recruitment - annual death and emmigration

Environmental Impact Assessment (EIA)

Report that presents advantages and disadvantages of development projects, including biotic and abiotic elements

Aims of an EIA

• Resource conservation

• Waste minimization

• Recovery of by-product

• Efficient use of equipment

• Sustainable development

Ecological footprint

The hypothetical area of land required to fulfill all the resource needs and assimilate all wastes

Ecological footprint formula (land requirement for food production)

per capita food consumption (kg yr^-1) / mean food production per hectare (kg ha^-1 yr^-1)

Ecological footprint formula (land requirement for absorbing CO2 from fossil fuels)

per capita CO2 emmision (kg C yr^-1) / net carbon fixation per hectare (kg C ha^-1 yr^-1)

Pollution

Presence or introduction of contaminants in which the environment is harmed and affects the health of organisms within

Pollutants in the atmosphere

Carbon Dioxide, Carbon Monoxide, Nitrogen Oxide, Sulphur Oxide, Ozone

Industrial waste

refers to the byproducts generated from industrial processes

Effects of Industrial waste

• Accumulation of heavy metals

• Dissolution of heavy metals

• Disposal of harmful waste materials

• soil, water contamination

Effects of Domestic Waste

• Habitat loss

• Deforestation

• Euthrophication

Agricultural waste

refers to the byproducts generated from farming and agricultural activities

Effects of Agricultural waste

• Eutrophication

• Accumulation of pesticides

Eutrophication

an increase in nutrient levels (nitrogen and phosphorus) in water bodies