1. Unit 4 – Climate Change

2. Earth’s Biosphere
The climate of a region is affected by interactions among components of Earth’s biosphere.
Earth’s biosphere is the thin layer of the Earth that is able to support life.
The relatively thin layer of Earth that has conditions suitable for supporting life is composed of all the living things on Earth and the physical environment that supports them.

3. Earth’s Biosphere Earth may be divided into four spheres
Biosphere (bio = living, Sphere = ball) ; The living layer around the planet
Includes – atmosphere, lithosphere, and hydrosphere

4. Earth’s Biosphere
Atmosphere (atmos = gas) ; The gas layer around the planet
Lithosphere (lithos = rock); The rock layer around the planet
Hydrosphere (hydro = water); The water layer around the planet

5. Atmosphere
Air is the mixture of different gases found in the Earth’s atmosphere.
The layer of gas that extends out 300km from the Earth’s surface.
Major gasses – Oxygen and Nitrogen
Trace Gases – Argon, carbon dioxide, helium, methane, and krypton

6. The Composition of the Atmosphere
The atmosphere is approximately:
78% nitrogen gas
21% oxygen gas
1% other gases
(argon, carbon dioxide, etc.)

7. Atmosphere
In addition to these gases, the atmosphere also contains atmospheric dust, made up of abiotic (non-living) and biotic (living) particles.
Air quality is affected by the quantity of particles.
Smog, a word combining “smoke” and “fog,” occurs when soot particles combine with car exhaust in the air.

8. The Components of the Atmosphere
The atmosphere is subdivided into regions according to their distance from Earth’s surface.
These layers are described in terms of temperature, chemical composition, air movement, and density, which may differ from place to place.

9. Layers in the Atmosphere

10. Layer
Altitude from the Earth’s Surface (km)
Temp Range (°C)
Characteristics
Troposphere
0-10
20 – 60
• 80 percent of atmospheric gas by mass
• can support life
• contains most of the carbon dioxide and water vapour in the atmosphere
• contains almost all of the atmospheric dust in the atmosphere
• where weather takes place
Stratosphere
10–50
0 – 60
• contains most of the ozone gas in the atmosphere, which protects living organisms from damaging high-energy radiation
• clumps of cells found but no other life
• Air temperature increases with height as ozone gas absorbs ultraviolet solar radiation.
Mesosphere
50–80
0 – 100
• very little gas
• Air is thin, and atmospheric pressure is low.
• fewer oxygen molecules (O2)
Thermosphere
80+
–100 to 1000
• Gas particles are hot during the day and cold at night.

11. The Lithosphere
The solid portion of Earth that floats on the semifluid portion of the mantle.
The lithosphere is home to many micro-organisms, plants, and animals, including humans. It is the outer surface of Earth (its crust) plus the solid part of the upper mantle.

12. The Lithosphere
It extends downward from Earth’s surface and varies in thickness from 5 km in the ocean to 100 km beneath the continents.
Only a few meters is warmed by the sun, the rest is warmed by decaying radioactive material

13. The Lithosphere
Movements in the lithosphere can affect climate. The science of plate tectonics describes how the different plates of Earth’s lithosphere move over the mantle.
When plates collide, mountains form. The windblown side of mountain ranges receive rain while the other side is dry.
Volcanic eruptions can spew millions of tonnes of ash high into the atmosphere, blocking the sun and cooling the global climate for a few years.

14. The Hydrosphere All of the water on Earth.
About 97 percent of this water is salt water in Earth’s oceans.
The other 3 percent is fresh water. Groundwater, lakes, and streams, ice in snow and glaciers

15. The Hydrosphere
Many different organisms, from whales to algae, live in the large water bodies of the hydrosphere.
Most organisms in the lithosphere or atmosphere need water to survive.
The hydrosphere is warmed by incoming solar radiation.

16. Weather vs. Climate
Weather is the condition of the atmosphere in a specific place at a specific time. It describes factors such as wind, temperature, humidity, & precipitation.
Climate refers to the condition of the atmosphere over a large area, averaged over many years.

17. Climate factors:
The 4 main factors affecting an area’s climate are:

18. Climate factors:
The 4 main factors affecting a specific area’s climate are (more factors tomorrow):
Latitude

19. Climate factors: The 4 main factors affecting an area’s climate are:
Latitude
Elevation

20. Climate factors: The 4 main factors affecting an area’s climate are:
Latitude
Elevation
Air masses that flow
over the area

21. Climate factors: The 4 main factors affecting an area’s climate are:
Latitude
Elevation
Air masses that flow over the area
Nearness to large bodies of water

22. Climate Zones: Biomes
A biome is a large geographical region with a defined range of temperature and precipitation - its climate.

23. Climate Zones: Biomes
A biome is a large geographical region with a defined range of temperature and precipitation – its climate.

24. Biomes
Each biome is characterized by the plant (and animal) life that is adapted to it. E.g. the cold, dry tundra is characterized by its lichens, mosses, and sedges.

25. The Science of Earth’s Biomes
Dividing Earth into biomes helps scientists study and understand how the biotic and abiotic components of each biome interact and how the biomes interact with each other.
Biome divisions also make it easier for scientists to predict how different groups of organisms may be affected by changes in a region, such as a decrease in precipitation or an increase in summer temperatures.

26. Climatographs
The climate of any particular area can be analyzed using climatographs which compare precipitation and temperature over time.

27. Canadian Biomes and Climate
The six terrestrial biomes in Canada are tundra, boreal forest (also called taiga), temperate deciduous forest, temperate grassland, temperate coniferous forest, and mountain.
Mountains show several different biomes as you climb, with tundra at the tops of the highest mountains.

29. Canadian Biomes and Climate

30. Canadian Biome Diagram pg 283-285 text