Any water or moisture also reacts

The presence of any reactive hydrocarbon also affects the contents of the air by reacting with the various species in the upper atmosphere. Where R is a hydrocarbon group  

There are many more reactions, also including a nuclear one in which some of the nitrogen atoms of the upper atmosphere are hit by high energy cosmic rays, or particularly neutrons. 

The radioactive carbon-14 isotope so formed is incorporated into carbon dioxide, and eventually by photosynthesis into plants and so into animals. .. including you. This is the basis of radioactive dating, as used by archaeologists (see also Section 1.4.4). 

Steps have been taken to replace all CFCs throughout the world, but some countries, owing to economic difficulties, are finding it hard to comply with the restrictions. 

Some natural events also produce noxious gases and particles that can have a major effect on climate. e.g. large volcanic eruptions. When the volcano Tambora (Indonesia) erupted in 1815, the dust cloud in the upper atmosphere kept out sunlight from many places in the world, so that 1816 was known as the year without a summer . 

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