The term “climate change” refers to changes in long-term trends in climate that have been caused by human activity. Since the Industrial Revolution, the extensive burning of coal and petroleum has resulted in large amounts of carbon dioxide being emitted to the atmosphere. Extensive land clearing has had similar results.

The Greenhouse effect is an analogy to a simple garden greenhouse. A greenhouse allows the rays of the sun to enter the greenhouse and then the glass traps the heat caused by the sunrays. The same effect occurs in the Earth’s atmosphere, except that instead of glass, water vapour and carbon dioxide (and other gases) trap the sun’s heat. As a result, the Earth is warming. These gases are called “greenhouse gases”.

The Earth’s atmosphere is very thin. Most of the atmosphere occupies only 11KM versus the Earth’s 12,600KM diameter (equivalent to a coat of varnish on a basketball).

The atmosphere has a limited capacity to absorb greenhouse gases. The oceans, trees and plants are able to absorb some of the gases generated, but the amount of greenhouse gases generated exceed the Earth’s natural capacity to absorb them. As a result, the levels of greenhouse gases have steadily increased since the Industrial Revolution

The impact of these greenhouse gases in the atmosphere has resulted in a measured increase in global average temperatures, an increase in sea level, a decrease in glaciers and snow cover in the poles and an increase in the frequency of severe weather events.