1. Ice Ages What is an Ice Age? Interglacial Interval
Long Term Decrease In Global Temperatures
Ice Age = Glacial Sheets Advance
Interglacial Interval
Time between ice ages
We are in one now!

2. Volcanic Activity
When volcanoes erupt they release large amounts of dirt and dust into the air.
This can block incoming solar radiation, sunlight, from reaching Earth
This causes climates to be cooler then normal
Short Term
Lasts 2-7 yrs

3. Do You Remember…. Why do we have summer and winter?
Seasons
Vocabulary Review
Why do we have summer and winter?
The Earth’s Tilt As It Rotates Around The Sun
What is a solstice?
**One hemisphere of the Earth is tilted towards or away from the Sun.
*Northern Hemisphere Tilted towards = Summer
*Northern Hemisphere Tilted Away = Winter
What is an equinox?
**Neither Hemisphere is tilted towards or away from the Sun.
*Fall and Spring

4. Solar Activity
The amount of sunspots present on the Sun can also affect Earth’s climate.
More Sunspots = Warmer Global Climates
Less Sunspots = Cooler Global Climates
The last time the Sun had minimal sunspots we experienced a mini ice age.
Rivers were frozen in June.
Least amount of Sunspots = Called the Maunder Minimum

5. Earth’s Orbit
Earth’s Orbit switches between a circle and an ellipse every 100,000 years.
Circular Orbit
Seasons are determined by the tilt of the Earth on its axis.
Elliptical Orbit
Seasons would be more intense
Seasons would be determined by physical distance between the Earth and the Sun

6. Earth’s Wobble
Every 26,000 yrs the Earth slowly changes which star it is tilted towards
Polaris or Vega
Polaris = We are currently facing
In another 12,000yrs we will be facing Vega
This will reverse our seasons
We will have summer in December and winter in June
We are tilted away or towards the Sun differently