1.1 Continents and oceans

• 7 continents & 5 oceans

1.2 Country Classification by income level

• LICs: low-income economies (Gross Nat’l Income per capita < $1086)

  • e.g) Uganda, Chad, and Ethiopia; Africa has the most LICs

• MICs: middle-income economies

• HICs: high-income economies (GNI per capita > $13,205)

  • e.g) Canada, U.S.A., Sweden

  • Biggest impact on global climate

1.3 Sustainability

• Sustainability: the ability to meet the needs of the present without compromising the ability of future generations to meet their own needs

  • Must take into account environmental, social, and economic factors

• We are living unsustainably, due to factors like population growth and a finite # of resources

1.4 The water cycle

• Evaporation: liquid turns into vapor; enters the atmosphere

• Condensation: vapor turns into liquid

• Precipitation: liquid water or ice particles fall to the Earth

• Interception: precipitation is stopped from reaching the ground by the presence of trees and other plants

• Infiltration: water seeps into the ground

• Surface run-off: precipitation that runs over the ground into streams/rivers

• Through-flow: infiltrated water flows through the soil

• Groundwater flow: infiltrated water flows through rocks

• Transpiration: movement of water up plants & into vapor; it enters the atmosphere

1.5 The structure and composition of the atmosphere

• The Earth’s atmosphere is composed of: nitrogen, oxygen, carbon dioxide, argon, and water vapor

• Try Some Milk Then Eggs

  • Atmospheric pressure decreases with height

• Troposphere (0-15km): where we live

  • Temp. decreases w/height; wind speeds increase w/height

  • Where global warming occurs

  • Tropopause = top layer

• Stratosphere (~15-50km): contains the ozone layer

  • Temp. increases w/height

  • Stratopause = top layer

• Ozone: absorbs UV radiation

  • 10-50km above the surface

  • Protects from skin cancer, a weakened immune system, & damage to vision/cataracts

• Mesosphere (~50-80km): no dust, ozone, or water vapor

  • Temp. declines dramatically the higher up this layer extends

  • Mesopause = top layer

• Thermosphere (80-1000km):

  • Temp. rises rapidly with height → absorbs UV rays

  • Thermopause = top layer

• Greenhouse effect:

  • UV radiation passes through the Earth’s atmosphere and is absorbed the Earth’s surface

    • Some energy is re-emitted back into the atmosphere as infrared radiation

    • GHGs absorb some of this infrared radiation, preventing it from leaving the atmosphere

1.6 Ecosystems

• Biome: a form of ecosystems that are smaller than the biosphere; a geographical region w/specific climate, vegetation, and animal life

• Ecosystem: all living things (biotic) together with all non-living things (abiotic) in an area

  • Biotic factors: producers, consumers, and decomposers

  • Abiotic factors: temperature, humidity, water, oxygen, light, pH

• Population: all the organisms of one species living in a defined area

• Community: a group of populations of different species that live together in an area and interact with each other

• Habitat: the place within an ecosystem where an organism lives

• Niche: the role of a species within the ecosystem

Biotic interactions

• Competition: both organisms require the same resource

  • Intraspecific: 2 members of the same species

  • Interspecific: 2 different species

• Grazing: when species move from one victim to another w/o fully killing its victim

• Predation: one organism consumes another in a dominant relationship

Photosynthesis: the process by which plants synthesise glucose using carbon dioxide, water and energy from sunlight

• carbon dioxide + water → glucose + oxygen (COWS → GO)

  • 6CO2 + 6H2O → C6H12O6 + 6O2

• Chlorophyll captures light energy for photosynthesis

• Limiting factors: availability of water, concentration of carbon dioxide & the availability of light

• Photosynthesis by marine autotrophs (e.g. phytoplankton) turn carbon into organic matter

• Carbon reservoir in the atmosphere → fixation by photosynthesis → in living things

  • Carbon found in living things as carbohydrates, proteins, fats, etc.

Food chains

• Producers: organisms within an ecosystem that can carry out photosynthesis

• Primary consumer: organisms within an ecosystem that derive their food from producers

• Secondary consumer: organisms within an ecosystem that derive their food from primary consumers

• Tertiary consumer: organisms within an ecosystem that derive their food from secondary consumers

• Decomposer: organisms within an ecosystem that derive their food from the bodies of dead organisms

• Trophic levels = feeding levels within food chains

• Energy is transferred between organisms in a food chain; starts with a producer

• Energy is lost as respiration and waste products

Aerobic respiration: the chemical reactions in cells that break down glucose molecules and release energy, carbon dioxide and water

• glucose + oxygen → carbon dioxide + water

• C6H12O6 + 6O2 → 6CO2 + 6H2O

Carbon cycle

• The ocean, atmosphere, and land are the biggest carbon reservoirs