Unit 1 - Introduction

• What would you need for intelligent life? (7 things)

  1. A star the right size (0.75-1.5) as big as the sun.

  2. A planet about the size of ours

  3. It has to be a terrestrial planet (made out of rock) (needs a surface)

  4. Lots of water - liquid water (0-100) degrees

  5. The planet needs to be the right distance from the sun

  Too Close - all the water will steam

  Too Far - all the water will be ice 15-20 C

  6. The planet will need to be a relatively circular orbit (so the planet is heated evenly)

  7. The planet will have to rotate on its axis relatively frequently (again so the planet is heated evenly)
• What 4 spheres make up the Earth? (BLAH)


  1. Hydrosphere - the worlds oceans (covers 50% of the surface)

  2. Atmosphere - the gas that is held to the surface by gravity

  3. Lithosphere - the rock (land)

  4. Biosphere - the very thin area of the 3 above that contains life
• What is the mass of the Earth?


  99% of the atmosphere is below 30 KM

  5 x 10 to the 15 tonnes
• What are the 2 main parts of the Earth's Atmosphere?


  1. Troposphere 0-10 KM (issue: climate change) (felt easier by humans)

  2. Stratosphere 10-50 KM (issue: hole in the ozone) (not as easily felt by us)
• What are Biochemical Cycles and Sources vs Sinks


  Constant movement in and out of the atmosphere

  Sources - where it came from

  Sink - where it's going to

  Ex: the carbon cycle
• What is Residence Time?


  how long the molecule is in the atmosphere for
• What kind of issue is short vs long RT?

  Short RT - local issue

  Long RT - global issue
• How long are these compounds in the biochemical cycle for?

  1. CFC (cholorfluorocarbons):

  2. Water in the oceans:

  3. Nitrogen in the Atmosphere:

  4. CO2 in the atmosphere:

  1. 100-150 yrs

  2. 3000 yrs

  3. 12 million years

  4. 44 yrs
• Hazard


  a set of circumstances/conditions that may cause harmful consequences
• Risk


  a probability (0-1) - a numerical value that represents the likelihood that something unpleasant will result from that hazard.

  To reduce the risk you have to incur a cost
• What are the 3 types of risk?


  1. data is available (ex: smoking)

  2. no solid data is available aka super sketchy evidence is provided

  3. harmful events that haven't happened (yet) (ex: accidents which are completely unknown)
• Ecology


  a branch of the biological science that studies the interactions between an organism and it's environment
• Biosphere


  1. Lithosphere (rock + soil)

  Atmosphere (air + space)

  Hydrosphere (water + oceans)
• Biomes


  - the terrestrial part of the biosphere is divided into biomes

  - Are distinguished by their climate, soils and the species they support

  - Defined by moisture and temperature

  - There are around 11 on Earth (we near live 3)
• Aquatic Life Zones


  - Like a biome but in the ocean

  - Defined by light, temperature and nutrients

  - The riches regions (of nutrients) are the estuaries (a place where a river system enters the ocean) (because the rivers bring in all their nutrients)
• 2 parts of Ecosystems


  1. Living - called biotic

  2. Non-Living - called abiotic
• What are abiotic factors?


  the physical and chemical components of the ecosystem

  Physical - Ex: temperature, moisture

  Chemical - Ex: ph of soil

  - Range of Tolerance - you need a certain range of conditions met in order to find specific species (optimal range for each species)
• What are biotic factors?


  other species in the ecosystem

  - food supply

  - predation (getting eaten or eating someone else)

  - Competition

  - Also have a range of tolerance
• Habitat vs Ecological Niche

  Habitat - where a species is found

  Ecological Niche - where it is found and what it does (location + purpose)

  Ex:

  Deer live in Assiniboine Forest (habitat)

  Deer live in Assiniboine Forest, eat grass and feed coyotes (niche)
• Generalized vs Specialized Niches

  Generalized - have a wider range of tolerance

  Ex: dandelions (yellow weed) + coyotes

  Specialized - have a narrower range of tolerance

  Ex: pandas + koala bears