Powerpoint covering the carbon cycle, greenhouse effect and enhanced greenhouse effect.

2. CARBON CYCLE

5. Feeding CO 2 in atmosphere and oceans Photosynthesis Combustion Respiration Death Excretion Formation of Fossil Fuels COW Decomposers

8. The Greenhouse Effect

10. High frequency IR from sun Earth radiates in lower frequency IR Earth The Green House Effect atmosphere

12. Mars Earth Venus T/ º C Size of greenhouse effects -57 -47 -46 + 477 -18 +15

18. Energy from Sun Energy lost to space Balance when T is constant

19. BUT some molecules in the troposphere have polar bonds. These absorb photons of IR radiation whose energy corresponds to the gap between the vibrational energy levels of the molecule. This increases the vibrational energy of the molecule and so increases the temperature of the stratosphere as the energy is passed on to other molecules when they collide.

20. Energy from Sun Energy lost to space With less energy lost to space there is now a net gain of energy by the earth – until a new balance is reached at a higher temperature.

21. Atmospheric Co2 ppm vol. source: Australian government Atmospheric co2 concentration and global change in average temperature since 1880 Source: NASA