The above table does not claim to be a complete list of the greenhouse gases, indeed others are still being identified. Among the most complicated, perhaps is Ozone, about which a few words are justified here. Ozone is toxic at the Earth's surface yet can be environmental beneficial in that its presence in the stratosphere plays a major role in limiting the harmful ultraviolet radiation reaching the Earth's surface, and yet even this benefit has, to be balanced by the fact that also in the stratosphere it acts like other greenhouse gases. One must realize that Ozone does not welcome the presence of many of the other greenhouse gases, even to the extent that its concentration in the upper atmosphere, and especially in high latitudes is at risk from attack and depletion by other gases. In fact in consequence, there is more concern over the depletion of Ozone by its interaction with other greenhouse gases, notably the ChloroFlouroCarbons, than in its role as an agent for climate change.
Ozone depletion threatens humanity through the incidence of skin cancer and genetic damage.
It also threatens natural mechanisms which currently automatically remove other gas hazards from the environment, such at the take-up of carbon dioxide by the oceans. The story of Ozone represents a prime example of the many difficulties which surround corrective policies in the matter of climate change, not to mention the tendency for attention to one problem serving to increase the danger from another. Generally the release of the greenhouse gases has a strong effect on the delicate balance of the atmosphere, and when there are greater levels of -these gases in the atmosphere, they will trap more heat in the lower atmosphere. If the world community fails to act on this problem, scientists calculate that the continuing increase of greenhouse gases could lead to an overall temperature increase of -2 'C worldwide over the next 100 years, perhaps more. Climatologists have observed a slight but fairly steady rise in temperatures since the 1880s, when reliable temperature records became available worldwide.