1. The steady state bottle in equilibrium.1

2. Turning the stand so that the weight of the bottle
presses on the outflow tube. 2

3. Positive feedback: as the water level rises the outflow decreases.3

4. Clouds remain one of the largest areas
of uncertainty in climate change.
Source: BigStockPhoto.com (© Silvia Bukovac) 4

5. When a plastic bottle with moist air is squeezed and released, nothing appears to happen.5

6. If smoke is added to the bottle, and it is then squeezed
and released, a ‘cloud’ forms. 6

7. A graph of annual mean global temperature shows a rise
of around 0.7 °C over the 20th century.
Source: Climate Change 2007: The Physical Science Basis (IPCC) 7

8. Warming is very likely to increase over the 21st century.
Source: Climate Change 2007: The Physical Science Basis (IPCC) 8

9. Predictions made using complex computer models show how temperature and rainfall may change.
Source: Climate Change 2007: The Physical Science Basis (IPCC) 9

10. Annual mean temperature anomaly for Reading.10