env midterm

3 major environmental problems

1. pollution (plastic pollution in the ocean)

2. resource depletion (ex. fossil fuel depletion)

3. loss of biodiversity (ex. extinction of species)

open system

exchanges both energy and matter across its boundary (ex. plant energy from light during photosynthesis)

closed system

only exchanges energy across its boundary (ex. carbon and nitrogen cycle)

isolation system

hypothetical concept in which neither energy or matter are exchanged

transfers

moves from one place to another (ex. water moving from river to sea)

transformations

a change in chemical nature, state, or energy (ex. liquid --\> gas)

gaia hypothesis

States that the environment on a global level has been changed for the better by life over the history of life on earth.

Steady-state equilibrium

an ecosystem that is maintaining a negative feedback loop and in a stable state

feedback loop

a circular process in which a system's output serves as input to that same system

positive feedback look

DESTABLIZING - will tend to amplify changes and tip the system

ex. the earth right now is in a positive feedback loop in which climate change is being accelerated

negative feedback loop

STABLIZING - reduces the effect of change and helps maintain balance.

disturbance

any disruption of an ecosystem that changes the resources, ability, or physical environment

systems with high resilience

diverse and complex ecosystems, more interaction between different species within the ecosystem, warmer temp, high reproduction rate

systems with low resilience

low reproduction rate, colder climate, less vegetation, less diverse ecosystem and biodiversity

5 resilience factors

1. diverse vegetation

2. interaction between species

3. high rate of reproduction

4. warm temp

5. size of ecosystem (bigger \= more resilient)

tipping point

the point at which an ecosystem is significantly changed to a new state (ex. coral reef death -- the coral reef is killed forever and can't regenerate)

sustainability

the use and management of resources that allows full natural replacement of the resources exploited and full recovery of the ecosystem

3 major indicators of sustainability

1. air quality

2. GDP

3. life expectancy

natural capital

Natural resources and natural services that keep us and other species alive and support our economies.

3 examples of natural capital

trees, water, pollination

renewable resource

A natural resource that can be replaced at the same rate at which the resource is consumed

Non-renewable resources

a resource that cannot be reused or replaced easily (ex. gems, iron, copper, fossil fuels)

perpetual resource

Essentially inexhaustible resource on a human time scale because it is renewed continuously. Solar energy is an example.

sustainable yield

Highest rate at which a renewable resource can be used indefinitely without reducing its available supply

economic depletion

When the costs of extracting and using what is left of a resource exceed its economic value

pollution

the presence in or introduction into the environment of a substance or thing that has harmful or poisonous effects.

point source pollution

pollution that comes from a specific site (ex. factories)

non-point source pollution

pollution that comes from many sources rather than from a single, specific site (ex. pesticides)

3 factors that determine the severity of a pollutant

1. chemical nature - how active/toxic it is to nature

2. concentration - the amount of harmful chemical per unit volume of air, soil, water

3. persistance - how long does it last in the environment

3 pollutant + their effects

1. carbon dioxide --\> green house gas built up in the atmosphere

2. organic waste --\> eutriphication, disease spread

3. nitrogen oxides --\> respitory infections, smog

3 major approaches to solving pollution problems

1. prevention: legislation + regulations

2. control: applying new technologies to extract pollutant from emissions/create alternatives

3.clean up/mitigation: extracting + removing pollutant from ecosystem

Drinking Water Treatment

1. river water is pumped into basin enough to power the plant.

2. coagulation: settles small vs. large particles

3. chlorine is added twice

4. floagulation : + and - particles separate

5. chemists test the water

wastewater treatment

1. gravity help water flow into plant

2. separate water and garbage

3. "bugs" eat the sludge remaining in the water

4. water treated with hyrdochloride

environmental impact assessment

1. screening and scoping

2. assessment of environmental risks

3. mitigation: what measures will be followed to minimize environmental risk

4. decision - making

5. monitoring

CBR calculation

(\# births/total pop) * 1000

CDR calculation

(\# of deaths/total pop)* 1000

NRI calculations

CBR-CDR/10

pop. density calculations

\# of people/ land area

human impact on water cycles

1. withdraws: for domestic/agriculture use

2. changing speed of where/when water can flow

3. discharges: adding pollutants to the water

4. diverting rivers/sections of rivers

history of human pop.

- pop grew at a slow pace for thousands of years because of the high death rates and lack of technology/medicine

-After European conquest population begin to grow bc of new agriculture

-the first billion hit by 1800 and in past 200 years the population has multiplied by 8

Human population pyramids