Environment /Nature VI Flashcards
What are the main greenhouse gasses?
- water vapor
- ozone
- methane
- nitrous oxide
- carbon dioxide
CO2
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
Carbon
- 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
- Canada
- part of Antarctica
- Greenland
- part of Africa
What countries/continents are in the eastern hemisphere?
- Europe
- Africa
- Asia
- Australia
- 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?
Photosynthesis converts:
- 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
Agriculture
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.
Niche
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)
