Rising average temperature drives climate change
Definition
Climate
The long-term pattern of weather conditions in a region or across Earth.
- Peer-reviewed evidence links a rise in average global temperature to climate change.
- Climate is the long-term pattern of weather, so climate change is a lasting shift, not day-to-day weather.
- The main cause identified is the increase in greenhouse gases from human activity.
Why the climate is hard to model
- Earth's climate is a very complex system with many interacting parts.
- This makes it hard to build models that predict future change exactly.
- Where models are uncertain, speculation and opinion can be presented as if they were fact.
- You should evaluate the quality of the evidence and separate opinion from fact.
Note
A simplified model cannot include every factor, so its predictions carry uncertainty; that uncertainty is not the same as the science being wrong.
Possible effects of a warming climate
Definition
Biodiversity
The variety of different living organisms in an area or across Earth.
Definition
Habitat
The place where an organism lives, including the conditions and resources it needs to survive.
- Sea levels may rise, causing more flooding and coastal erosion.
- Storms may become more frequent and more severe.
- The amount, timing and distribution of rainfall may change, causing water stress.
- Food production may fall in some regions as growing conditions change.
- Many species may shift their habitats or decline, reducing biodiversity.
Exam technique
- You are expected to appreciate these effects, not recall exact figures, so give a range of effects rather than one.
- On 'evaluate' questions, say whether the evidence is peer-reviewed and separate proven effects from speculation.
Self review
- What is the main cause of current climate change?
- How is climate different from weather?
- Why is it difficult to model the climate accurately?
- Give three possible effects of a warming climate.
- Why can opinions sometimes be presented as if they were fact?
