Exam 3 Flashcards
Balance & Equilibrium
light from the sun carries it to earth, warming it up. Some of the excess energy escapes into space. If energy in = energy out, earth is at equilibrium
Albedo
percentage of solar radiation reflected back into space by an object or surface
Land & Ocean Albedo
low albedos, they absorb a lot - 0.1-0.4
Snow & Ice Albedo
high albedos, they reflect a lot - 0.7-0.9
Earth’s Average Albedo
0.3 or 30%
Greenhouse gasses
the atmosphere allows sunlight in, but prevents heat from escaping
Nitrogen and Oxygen are the two main gases in our atmospheres, but they don’t warm it.
Greenhouse gasses are water vapor, methane, and carbon dioxide
Industrial Age
has contributed to our pollution through natural gas, coal and oil
In the Past
volcanic eruptions used to cause so much carbon dioxide that it reached concentrations 400x hotter than now, but life always survived
Atmospheric layers
Exosphere Thermosphere Mesosphere Stratosphere Troposphere
Without gasses, the Earth’s surface would be ______ cooler
59 degrees
Earth, Venus, Mars
Earth’s atmosphere has only a little amount of CO2: 387ppm, atmosphere is thicker and denser than mars, but not as thick as Venus
Methane traps ____ as much energy as CO2
8x
Ozone layer
only contributes 3%-7% of greenhouse gasses
Blocks UV light, w/out it we couldn’t live here
CFC (chlorofluorocarbons)
coolants in refridgerators and air conditioners responsible for depletion of ozone layer
Human Activities that Produce Greenhouse Gases
burning fossil fuels, breathing, livestock
Offset Gases by
electric cars, less deforestation and using selective cutting instead, forest fires
Trees Burning Produces
lots of CO2
Anthropogenic methane
much of it comes from waste and decay in our landfill, human waste and sewage breaks down into methane
manure from chickens, pigs, cattle, and sheep account for 37% of all human-related methane
Nonhuman sources of Greenhouse Gases
molten rock and magma are rich in CO2, bacteria, frozen soil in the artic
Alternate energy sources
dams, windmills, solar panels, windmills, wave power station
Carbon capture and sequestration
photosynthesis, business factory offsets, preserving forests, some trees don’t produce as much oxygen
Biofuels
made from plant products
CO2 burned in replaced w/plants
not carbon neutral
Hunters & Gatherers
our ancestors got food by hunting for food
omnivores
only animal that practices agriculture
agriculture couldn’t develop until our ancestors had evolved to the point of having foresight and long term planning
Theories
- Oasis Theory. climate became drier, causing suitable habitats to shrink, so people had to live closer together in the small areas that still had food plants
- In areas where cereal grains grew well natural, humans could settle in one spot and still have enough to eat, they did not have to move from place to place
- Even w/out climate change, human population became dense enough that more food was needed to prevent starvation. Pop densities tend to be lower in non ag. societies
When did agriculture develop
several times in scattered areas 11,000 years ago in the fertile crescent between the Tigris and Euphrates Rivers
Agriculture and the Biosphere
timing of the earliest cities coincides with the retreat of glaciers in N. Eurasia and N. America, spread from Sumer to Nile river valley
Current state of crops
wheat, corn, soybeans, potatoes, and sugarcane now occupy a large percentage of the land surface area. Farming and herding mean few natural areas are left
Not-So-Awesome Side of Farming
presence of crops allows insects & other herbivores to expand their ranges
water becomes polluted from pesticides
large amount of food has allowed the pop to grow to 6.8 billion
human pop consumes resources
w/out ag there would be fewer ppl and less ecological damage
Neolithic Revolution
10,000 BCE, when humans discovered agriculture
allowed ppl to stop being nomadic and form permanent settlements
humans domesticated animals and plants for food
selective breeding for higher yield
Pros
Controllable food supply
more food = more people
Ag creates permanent settlements
Cons
We are vulnerable to environment (climate/weather can kill crops
sicknesses and diseases spread quickly
Agriculture negatively impacted our health
Pre Agriculture
hunters & gatherers are nomadic & move frequently =fit
low carb, low sugar diet = good oral health and weight range
sparse and low pop. centers, low disease risk
Post Agriculture
now we sit for 8+ hours a day = bad for health
high carb/high sugar diet
cavities, overweight
dense pop. centers = high rise of disease & illness
Modern Agriculture
crop fields, diversified by crops cattle grass, oats for horses herbs & spices cotton & flax = cloth tree farms orchards ranches for cattle forestry: cutting trees for lumber hydroponically: cultivation
Organic vs. Conventional farming
organic means no synthetic chemicals can be used
crop must be cultivated on land, not treated w/chemicals for at least 3 years
conventional farming, manufactures artificial fertilizers
pesticide and herbicides
Selective Breeding
artificial selection, the process by which humans use animal breeding and plant breeding to selectively develop particular traits
Seed Banks
stores seeds preserve genetic diversity; hence there is a type of gene bank
sharing seeds help plant breeders increase yield, disease resistance, drought tolerance, nutritional quality
Plant defenses that have developed give us
unique compounds
We use synthetic chem to create
new medicines from plants
Modern medicine uses at least ____ different plants
72
Plant medicine can be used:
topically, as tea, ingested whole, or extracted and purified into pills/medicines
Medicinal Plants
plants contain numerous undiscovered chemicals that promote good health
rather than trying to isolate one or two specific compounds, it is best to use the whole plant, unrefined as a functional food or medicinal food
Tea & Coffee
require little processing
chemicals exert strong effects on us
caffeine stimulates our central nervous system, quickens reaction time, relieves tiredness
tea has more caffeine than coffee, but we drink it in lower concentrations
Cola comes from
kola nut
Alcohol
a depressant that slows our reaction speed, high concentrations of ethanol in our blood interferes w/coordination and can be fatal when BAC levels reach 0.4% climate impacts flavor of wines
Psychoactive Plants
tobacco- produces nicotine Marijuana - cannabis Opium - morphine, popyseed, heroin coca plants - cocaine Peyote - cacti hallucinogen
Plant-Derived Medicines
Aloe vera
asprin
cephaelis
Vinblastine
Newly Discovered Plant-Derived Drugs
years of testing are required before approved for human use
process begins w/screening of extracts of thousands of species for some indication of beneficial biological activity
compounds are extracted using oils, alcohols, or water
beneficial compounds may be extracted with a toxic one
only 5 have been approced since 2001
Plants Discussed in Class
Aloe Vera Willow Trees - Asprin Chinchona Trees - Quinine (malaria) Atropa Plants - Atropine (anesthetic) Purple Foxglove - irregular heartbeat Mayapple - cancer, malaria, psoriasis
Air Capture
Bill Gates’s plant sucks CO2 out of the atmosphere -the work of 40 million trees
