View
223
Download
0
Category
Tags:
Preview:
Citation preview
STUDYING CLIMATE CHANGE
In studying ancient climates, scientists follow an important principal: If plants or and animals need certain conditions to live in, then similar plants and animals in the past also required those conditions.
2- Tree RingsThickness of the tree ring indicates the climate. (A thin ring- dry or cool, and a wide ring- warm or wet)
3- Pollen RecordsPollen records (buried under layers of mud) indicate the types of plants that
grew in an area thousands of years before.
ICE AGES During each ice age, huge sheets of ice called
glaciers covered large parts of the Earth’s surface.
Interglacial Periods- the warm period of time between ice ages
Last Ice Age- Ended about 10,500 years ago Next Ice Age- 90,000 years? 490,000? Maybe?
CAUSES OF CLIMATE CHANGE
Earth’s Position- to the sun (orbit) or the tilt of the Earth
Solar Energy- the amount of energy from the sun
Movement of the Continents- about 225 million years ago Pangaea broke apart and the continents moved to their present positions
CHECKPOINT QUESTIONWhy were the oceans lower during the ice
ages?Much of the water on Earth was frozen in
ice sheets that covered the land.
Recommended