Download Earth*s Climate System

Factors Affecting Climate Change
 Earth is surrounded by a layer of gases called the
atmosphere.
 The characteristic pattern of weather conditions
within a region averaged over a period of time is called
the climate.
Is climate change new?
No, climate change is a natural part of Earth’s history.
For example, thousands of
years ago, thick ice sheets
covered most of Canada and a
large portion of the United
States.
Factors Affecting Climate Change
Make a list of as many factors that affects climate
as you are able….
Factors Affecting Climate Change
1. The Sun
2. The Earth
3. The Atmosphere
4. The Hydrosphere
5. Moving Continents
6. Human Activity
1. The Sun
 Solar energy hits the Earth’s surface and
the heat leads to winds, rain and other
features of weather.
 A sunspot maximum occurs every 11
years, which is thought to have added to
climate change in the past.
2. The Earth: Orbit,
Tilt and Rotation
 Eccentricity: over 100 000 years our orbit
goes from circular to elliptical, and back.
This affects the length of seasons.
 Tilt: over 41 000 years tilt changes by
about 2.4. When closer to upright the
seasons are less variable. When more
tilted the seasons are more variable.
 Wobble: Earth is not a perfect sphere, so it
wobbles a bit on its axis as it rotates. Has
the same impact as tilt.
2. The Earth: Latitude
 Climate is hotter at
the equator due to
the angle at which
the Sun’s rays hit
Earth, not how close
we are to the Sun.
3. Atmosphere
 Made of mainly nitrogen, oxygen and water vapour.
 Greenhouse Effect: natural warming caused when
gases in Earth’s atmosphere absorb thermal energy
from Sun and Earth.
 Without it, Earth would radiate it’s energy back into
space and it would be a lot colder on Earth.
3. Atmosphere
Winds
 Wind starts as an uneven
heating of the Earth’s
surface which causes
high and low pressure
areas and followed by
the movement of air
from the high pressure to
the low pressure.
Ocean Currents
 Energy from the moving
air is transferred to the
surface of the water,
causing the water to
move and to redistribute
heat.
4. Hydrosphere
 Water in all its forms composes the hydrosphere.
 Because water has a large specific heat capacity (it
takes a lot of energy to raise the temperature of a
given volume of water) the Oceans and lakes act as
stores of heat which is then moved around the
planet in ocean currents.
5. Tectonic Plates
 Earth’s outer layer is made of tectonic plates which
move a few cm each year.
 Shapes of oceans and continents are always changing
which alters the movement and distribution of heat
at the surface of the planet.
5. Volcanic Eruptions
 Movement of tectonic plates
produces volcanic eruptions.
 Ash reflects solar radiation
back to space creating a
cooling effect on the global
climate.
 Eruptions may also raise global
temperatures by emitting
greenhouse gases.
6. Human Activity
 However …none of these factors can explain the warming
trend we are experiencing now.
 There is growing evidence that the present change in
climate is at least partly anthropogenic in origin (caused by
humans).
 Due to burning fossil fuels (cars, factories, farming, home,
electricity, etc) we are releasing huge amounts of
greenhouse gases into the atmosphere.
Reconstructing Paleo-climates
Nova – Ice Mountain
Ice Core Graphing Activity