Exercise 3. Paraphrase the following sentences

1. In the case of high-altitude airliners which frequently fly near or in the stratosphere, non-CO2 altitude-sensitive effects may increase the total impact on anthropogenic (man-made) climate change significantly.

2. Contrails are visible line clouds that form in cold, humid atmospheres and are thought to have a global warming effect (though one less significant than either CO2 emissions or NOx induced effects) SPM-2.

3. Soot absorbs heat and has a warming effect; sulfate particles reflect radiation and have a small cooling effect.

4. The IPCC has estimated that aviation is responsible for around 3.5% of anthropogenic climate change, a figure which includes both CO2 and non-CO2 induced effects.

5. If other industries achieve significant cuts in their own greenhouse gas emissions, aviation’s share as a proportion of the remaining emissions could also rise.

Exercise 4. Finish the sentences.

1. Like all human activities involving combustion, most forms of aviation release carbon dioxide (CO2) into the Earth's atmosphere, contributing to...

2. The contribution of civil aircraft-in-flight to global CO2 emissions has been estimated at around...

3. CO2 emissions from aircraft-in-flight are the most significant and best understood element of aviation's total contribution to...

4. High altitude (8-13km) NOx emissions result in greater concentrations of O3 than surface NOx emissions, and these in turn have a greater...

5. Contrails are extremely rare from lower-altitude aircraft, or from...

6. Soot absorbs heat and has a...

7. Per passenger kilometre, figures from British Airways suggest carbon dioxide emissions of...

8. Accordingly, more recent UK government policy statements have stressed the need for aviation to address its total climate change impacts and not simply the impact of...

9. Per passenger kilometre, figures from British Airways suggest carbon dioxide emissions of 0.1 kg for...

10. Sulfate particles reflect radiation and have a...

Exercise 5. Make up your own sentences using the following terms:

carbon dioxide (CO2), soot, climate change, sulfate particles, emission, contrails, the Intergovernmental Panel on Climate Change, greenhouse gas, warming/cooling effect.