1.3 - Evidence of Past Change Flashcards
What are the sources of evidence that climate change is natural?
Ice cores
Pollen records
Tree rings
An example of a historical sources (e.g. painting)
What things have disappeared that show us that climate has changed naturally?
Megafauna have disappeared, e.g. dinosaurs and woolly mammoths are extinct
Fossilised remains of animals, plants or pollen that no longer live in that area
What can we see in the landscape that tells us climate has changed naturally?
Landforms like U shaped valleys left by retreating glaciers in Scotland
How do ice cores tell us about natural climate change?
Frozen water contains oxygen isotopes - these indicate the past levels of carbon dioxide
What can paintings tell us about past climate change?
Paintings show us evidence of the Little Ice Age, e.g. ice fairs in London
How did past climate change have an impact on people?
Less agricultural output - land not so productive
Less food means price rises and famine
People migrate from hostile environments e.g. Vikings in Greenland
Disease spreads e.g. bubonic plague
New crops can be grown e.g. potatoes like wet and cold climate
How did past climate change have an impact on ecosystems?
More sea ice in northern latitudes
Food chains collapse - affects food supplies
Some animals experienced rapid population decline e.g. Seals
Plant growth slows down
How does ice cores store CO2 levels?
Tiny bubbles or air are frozen into the ice
What are isotopes
Water, whose atoms have different numbers of neutrons, depending on temperature?
How do we collect ice cores?
Drill down into the ice sheet and collect a long, thin cylinder of ice.
Each layer of ice relates to a different year
How do tree rings help tell us about climate change?
Growth rings are wider in warmer, wetter climates
They’re narrower in colder, drier climates
