Environmental science test 1

environmental science

the interdisciplinary study of humanity’s relationship with the other organisms and earth; it combines many disciplines such as biology, geography, chemistry, geology, physics, economics, sociology, anthropology, resource management, agriculture, law, politics, engineering, and ethics

biological environment

encompasses the organic components, organisms (including humans) and their relationships on earth

physical environment

consists of the incoming radiant energy of the sun, air, water, and soil which is required for life on earth

social environment

the immediate physical and social setting in which people live or in which something happens or develops, including the culture that the individual was educated or lives in and the people and institutions with whom they interact

Rachel Carson’s “The Silent Spring”

brought pesticide issue to public view arguing that pesticides, including DDT, were poisoning wildlife, environment, and humans

DDT (dichlorodiphenyltrichloroethane)

* and organochloride first synthesized in 1874
* insecticidal properties not discovered until 1939
* effective control of malaria and typhus during WWII
* Novel Prize in Medicine 1948 to Paul Mueller for discovery that DDT could be used as pesticide
* 1950-1980: DDT used worldwide in agriculture as pesticide
* US banned its use in 1972

Scientific method

* recognize problem or unanswered question
* develop hypothesis to explain problem
* design and perform experiment to test hypothesis
* analyze and interpret data to reach conclusions
* share new knowledge with other scientists

hypothesis

* statement, not a question
* predicts the outcome of an experiment (testable)
* ok to reject

pseudoscience

trying to prove something or having an agenda

a modest proposal

satirical essay by Jonathan Swift in 1729; proposal for preventing the children of poor people for being a burden to their parents or country and for making them beneficial to the public; suggests that the Irish might ease their economic troubles by selling their children as food for the rich

malthusian catastrophe

English economist Thomas Malthus said that it would be impossible to maintain a rapidly multiplying human population on a finite resource base 200 years ago

Malthus’ 3 premises

1. food is necessary for people to survive
2. passion between sexes is necessary and will remain nearly at its current rate, so children will continue to be born
3. the power of population growth is infinitely greater than the power of earth to produce subsistence

anthrop

human

eco

nature

what sets humans apart

culture and technology

what makes us a part of the ecosystem

ecological limitations

s-shaped curve

population initially shows exponential growth, then the population numbers level out as it approaches K

Carrying capacity (K)

The largest population a particular environment can support sustainable, assuming there are no changes in that environment

exponential growth

the larger the population gets the faster it grows

population ecology

a branch of biology that deals with the number of individuals of a particular species found in an area and how and why those numbers increase or decrease over time

demography

the scientific study of the sum of our individual acts as they affect measurements of the population

demographers/research

* study population statistics and causes/consequences of changes in population


* can help societies/governments make social, economic, political, resource use decisions for individuals, municipalities, states, and countries
* enable us to understand the environmental and cultural consequences of our decisions and can help us implement the decisions necessary for the quality of life we want in the future

migration

movement from one region/country to another to establish residency

immigration

migration into a region/country

emigration

migration out of a region/country

population increase

(birth+immigration)-(deaths+emigration)

growth rates

rate the population increases or decreases, predict future population size (cruse birth rate-crude death rate)

crude birth rate

number of live births per 1,000 people (# of live births/total population x 1,000)

crude death rate

number of deaths per 1,000 people (# of deaths/total population x 1,000)

zero population growth

when birth rates=death rates (immigration=emigration)

negative population growth

death rates outnumbers birth rates (emigration> immigration)

Less developed countries

countries like high growth rates

highly developed countries

countries with low growth rates

general fertility rates

\# of live births per 1,000 women of child-bearing age (15-49

age-specific fertility rates

\# of live births per 1,000 women of a specific age group

total fertility rates (TFR)

average # of children a woman will bear in her lifetime (average family size)

replacement fertility

\# of children a couple must produce to replace each parent

age distribution

\# of individuals of each sex and age for a population

population profiles

pyramidal: rapid growth

constructive: slow growth

stationary: no growth

IPAT (I=PxAxT)

equation that shows the relationship between environmental impacts and the forces that cause them, where I represents impact

atmosphere

a layer of gases surrounding a material body of sufficient mass that is held in place by the gravity of the body

what do pressure and oxygen do as altitude increases

decrease

troposphere

* thinnest layer, but heaviest air mass
* where weather occurs (jets fly at top to avoid turbulence)
* temperature decreases with altitude

stratosphere

* in lower region temperature remains constant with altitude
* in upper region, temperature increases with altitude
* contains the ozone layer surrounding earth

mesosphere

* temperature decreases with altitude
* coldest temperatures in our atmosphere

thermosphere

* temperature increases with altitude
* hottest temperatures in our atmosphere

ionosphere

* extends from the lower thermosphere into the exosphere
* solar wind is deflected by the earth’s magnetic field where its charged particles emit various colors of light- creating the Aurora Borealis or Australis

auroras

lights are always present, as close to the poles as possible, winter is usually the best time to view them, peaks every 11 years

rotation

24 hrs

revolution

365\.25 days

elliptical

shape of earth’s orbit

aphelion

july 4th, 94 million miles from earth to sun

perihelion

jan 3rd, 91 million miles from earth to sun

summer solstice

furthest north the sun appears to travel to those of us in the northern hemisphere (longest day of the year)

tropic of cancer

latitude where the sun is directly overhead on the summer solstice

winter solstice

furthest south the sun appears to travel to those of us in the northern hemisphere (shortest day of the year)

tropic of capricorn

latitude where the sun is directly overhead on the winter solstice

autumnal equinox

day the sun is directly overhead of the equator in the autumn

vernal equinox

day the sun is directly overhead of the equator in the spring

temperature

a measure of how warm or cold an object feels

* fahrenheit 32=freezing 212=boiling
* celsius 0=freezing 100=boiling
* kelvin 273.15=freezing 373.15=boiling

heat

internal molecular energy that flows from hot objects to cold objects

conduction

transfer of heat through electron and molecular collisions

convection

transfer of heat through actual movement or circulation

thermal convection

rising warm air in the atmosphere

advection

horizontal air currents (wind)

radiation

transfer of heat through space from one object to another

solar radiation

energy from the sun

* 20% absorbed by gases and clouds
* 30% reflected or scattered back into space
* 50% reaches earth

4 basic principles of radiation

1. all objects emit and absorb radiant energy over a range of wavelengths
2. good absorbers are good emitters (blackbody)
3. Hot objects radiate more energy than cold object
4. hotter objects emit shorter wavelengths and higher frequencies

electromagnetic radiation

* waves travel through space at the speed of light 300,000km/sec
* solar radiation: shorter wavelength (higher frequency) emits more energy
* terrestrial radiation: longer wavelength (lower frequency) emits less energy
* sunlight is: 43% visible light, 49% IR, 7% UV, >1% other

how radiation may be

absorbed, transmitted, redirected, reflected, and scattered

diffused light

scattering of light by dust particles and gas molecules

blue skies

scattering of blue light by nitrogen gas molecules

red skies

scattering of red light by dust particles

why sunsets/sunrises appear red

sunlight travels a longer path through the atmosphere at that time causing more scattering, removing shorter wavelengths (blue, violet) and leaving sunlight consisting of longer (red) wavelength

greenhouse gases

gases that absorb infrared radiation in the atmosphere

* in the absence of GHGs, Earth’s average surface temperature, which is currently 14 C would be as low as -18 C

special properties of water

* only liquid found in large quantities at the Earth’s surface
* found in all three states at earth’s surface
* great capacity to store heat
* solid phase is less dense than its liquid phase (ice floats)
* forms hydrogen bonds
* dissolves more substances than any other solvent

albedo effect

warmer temperatures→ less snow and ice→more sunlight absorbed by land and sea → warmer temperatures

* surface without snow or ice absorbs more heat
* surface with snow and ice reflects more heat

why water heats and cools faster than land

* water is highly mobile (heat penetrates more than surface)
* water is transparent, allowing radiation to penetrate deeper than land which is opaque
* evaporation more pronounced over water (cooling process is more pronounced)
* specific heat of water is 3x that of land

specific heat

amount of heat required to raise the temperature of a substance by 1 degree

thermal inertia

resistance to a change in temperature

(a large body of water exhibits a greater resistance to temperature change than land because of difference in specific heat)

ocean currents

transfer warm water from the equator to polar regions, and cold water to equatorial regions

latent heat

latent heat is he energy released or absorbed by a chemical substance during a change of state that occurs without changing its temperature, meaning a phase transition such as the melting of ice or the boiling of water

calorie

the amount of heat requires to raise the temp of 1 gram of water by 1 degree C

melting

solid to liquid

absorbs heat from the environment

freezing

liquid to solid

releases heat to the environment

evaporation

liquid to vapor

absorbs heat from the environment

condensation

vapor to liquid

releases heat from the environment

sublimation

solid to vapor

absorbs heat from the environment

deposition

vapor to solid

releases heat to the environment

humidity

a general term that refers to the amount of water vapor in the atmosphere

* depending on the temp of the air, there is a certain ratio of gaseous water to liquid water
* water will either evaporate or condense until this equilibrium is met

relative humidity

percentage tells how close the air is to saturation

saturation

100% relative humidity

how is relative humidity changed

* adding (evaporating) or subtracting (condensing) H20 vapor
* changing the temp (drop in temp, relative humidity increases)(rise in temperature, relative humidity decreases)

dew point temp

temperature at which air capacity shrinks to cause saturation (100% humidity) and then condensation (dew)

low dew point temp

dry air

high dew point temperature

moist air

clouds

visible aggregate of minute droplets of water, or tiny crystals of ice (or both)

precipitation

when the condensation droplets get big enough, gravity takes over and this occurs

* two conditions must be met: saturation or surface

cirrus

* clouds are high, white, and thin
* they are separated or detached and form delicate veil-like patches or extended wispy fibers and often have a feathery appearance

cumulus

* consist of globular individual cloud masses
* normally they exhibit flat base and appear as rising domes or towers
* cauliflower-like structure