Flashcards in Environment /Nature VI Deck (35)
What are the main greenhouse gasses?
- water vapor
- nitrous oxide
- carbon dioxide
(chemical compound: combination of carbon and oxygen)
- A carbon compound and greenhouse gas
released into the air when:
- trees are cut down
- fossil fuels are burned
- animals exhale
- A chemical element that forms organic compounds with other elements, such as oxygen (O2).
- Chemical element symbol: C
- Oxygen and carbon together make Carbon dioxide (CO2)
What countries/continents are in the Western Hemisphere?
- North America
- South America
- part of Antarctica
- part of Africa
What countries/continents are in the eastern hemisphere?
- part of Antarctica
When did Pangea start to break apart?
200 million years ago.
What is the substance in Carboniferous organisms that we harvest as fuel?
The plants and animals absorbed energy from the sun - energy that was stored as carbon molecules in their bodies.
- these organisms died and were compressed into the earth.
- over millions of years, layers of earth formed on top of them and became rock.
- their weight produced pressure and heat that changed the decaying matter into hydrocarbon energy.
How does an organism transform food into energy?
After it consumes the food:
- enzymes in the organism (the eater) break down the food into its different chemical properties.
- it then used the chemicals as energy
(Humans burn fats in their cells, for example)
How does the sun power (almost) all life on earth?
Of the total sunlight falling on earth:
- 30% is reflected
- 50% is converted to heat
All the rest powers the water cycle - evaporation, rain, wind, etc.
(Less than 1% is used by living plants)
- But that 1% of solar energy provides all of life's food needs through photosynthesis.
How does photosynthesis provide all of life's food needs?
- solar energy into stored chemical energy
In the cells of green plants, CO2 from the air, water from the earth, and light from the sun react to produce: sugar
- sugar is a complex organic compound that stores chemical energy for later use.
- oxygen is released as a by-product
- this stored chemical energy drives all the biochemical cycles of the earth (except some undersea ones)
Which biogeochemical cycle does photosynthesis not drive?
Some types of undersea bacteria that convert volcanic heat into chemical energy
In terms of the food web, farming means a:
- simplification and organization of the flow of energy
The farmer uproots (or chases away, or burns off) unwanted species.
He sows only those crops that are fit for human consumption
What happens as a result of agriculture (farming)?
All (or nearly all) the plant energy on a given plot of ground now flows into human mouths at the expense of:
- the other species that used to find a niche there.
A species place in a particular ecosystem that has what it needs to survive.
What effect did the creation of agriculture have?
Human society experienced an influx of energy.
This had two major effects:
- Population growth
- social organization
Unlike hunter/gatherer societies, more offspring was desired (more people to work the fields)
- this led to a population explosion
Also, whenever a complex system has a supply of energy coming in, the system tends to:
- organize itself
(Division of labor, social hierarchies, government committees, temples, markets)
What has the human niche almost always been?
- we have been hunter/gatherers for 99% of our history
What was the hunter/gatherer life like?
- Nomadic (go where the food is)
- population control was essential (groups tended to be no more than 50)
- if a group got too large, part of it split off
What changed hunter/gatherer societies?
The mastery of fire.
- it was a useful, hidden energy derived from wood
- it was a portable non-food energy that let people live anywhere (climate was no longer a barrier)
What was the first energy conservation technology?
What effect did the mastery of fire have?
It created the first population explosion as people started to spread all over the world.
What occurred at the end of the last ice age?
10,000 years ago
People had invented fire and weapons and tools.
- they became super predators (hunters began using fire to flush game, driving whole herds over cliffs)
- this led to the theory of Pleistocene overkill (theory that many of the mammoths and giant elk were killed not by climate but by over zealous hunters)
What happened shortly after the era of Pleistocene overkill?
Humans began to develop agriculture
How much of the earth does the ocean cover?
North American mountain chain
- the chain of mountains makes a barrier between east/west travel.
- partly in Canada, but mostly in the US.
- 300 miles wide x 1,500 miles long.
- 3,000 feet high
- runs from Newfoundland to Alabama
- Appalachia is a term used to refer to southern parts of the area: refers to parts of Kentucky, Tennessee, Virginia, and W. Virginia, and North Carolina
Coast states which border the Gulf of Mexico.
International date line
Line that runs along the prime meridian. (Pole to pole)
- separates calendar days
Vertical slices which tell what time it is on earth at some particular point.
If you start at the west coast of Africa and proceed east around the globe, you add an hour at each slice.