Climate Change: Evidence
Geography: Cambridge International GCSE (2027 Exams), topic 5.1.1
What is the Evidence for Climate Change?
We can see patterns in the Earth's climate over time using 4 main methods:
How do ice cores show climate change?
- Ice cores can be extracted by drilling into ice sheets.
- Each year, a new layer of ice freezes onto the top of an ice sheet.
- Examining the gases in each layer of ice can show us what the climate and temperature were like hundreds of thousands of years ago.
- Sometimes there are fossils or sediments that can give scientists even more information.
How do tree rings show climate change?
- Every year, a new ring forms in the trunks of trees.
- Rings are thicker in good conditions for growth (temperate and wet climate).
- Counting the number of tree rings can show that tree's age.
- Tree rings give us data on the climate and temperature for up to the last 10,000 years.
How does pollen analysis show climate change?
- Plant pollen can be preserved in sediment.
- Comparing plant pollen from sediment and plant pollen from now can indicate what differences have occurred between the current climate and past climate.
How do temperature records show climate change?
- Temperatures have been recorded globally since 1850, however, global records are a lot better from the last 50 years.
- This data is very reliable but only stretches back 170 years.
Test yourself on Climate Change: Evidence
How many layers of ice form on the top of ice sheets each year?
How do tree rings differ in warm and wet conditions?
Which features of tree rings are useful to scientists?