Even though species have occupied the Earth for only a minute period of the Earth's existence, it is only now that we are witnessing an altering of the chemical content of our entire atmosphere from 10 to 100 times the rate of its natural change over the past 100,000 years. An example of this is the projected Global Warming, which has been contributed to the over excessive use of fossil fuels, deforestation of our tropical forests, and a depletion of the life sustaining ozone in the stratosphere caused by the overuse of chlorofluorocarbons and other chemicals. These problems will continue to escalate until they trigger significant thresholds of change. Once this threshold has been crossed, there will be no turning back. Unpredicted lasting and drastic effects will be inflicted on the ecosphere, which supports all living species on this planet.

The change in the average surface temperature of Earth and its climates are the result of a number of interacting factors. Earth has existed for 4.6 billion years, and during this time there has been pronounced changes in the composition of the atmosphere, geosphere, hydrosphere and Biosphere. There have also been changes in the interactions between these sections of the ecosphere. When the ice age occurred 10 000 years ago, the coldest point of the Earth's surface temperature was only 5degC cooler than it is today.

The chemical composition of the troposphere and the stratosphere determines earth's mean surface temperature and therefore its climate, an effect of heat trapped in the troposphere by the natural Greenhouse Effect. The temperature is determined by the concentrations of heat trapping gases in the troposphere (i.e. Carbon Dioxide, Water Vapour, Ozone, Methane, Nitrous Oxide and chlorofluorocarbons). Increase these concentrations faster than they can be removed and the Earth's surface temperature increases, decrease them faster than they are emitted then the earth's surface temperature drops. Since the Industrial Revolution, in particular 1950, enormous quantities of greenhouse gases have been released into the atmosphere.

The concern lies with these gases amplifying the natural greenhouse effect and therefore turning up the earth's thermostat rapidly. Matters are made worse by reducing the Earth's ability to remove carbon dioxide through photosynthesis by global deforestation. Deforestation, and especially wholesale clearing and burning of tropical forests, accounts for approximately 20% of the increase in carbon dioxide levels. This is higher still were it doubles in MDC's and quadruples in LDC's. Farming, forestry, industry and motor vehicles also release greenhouse gases, mainly methane, nitrous oxide, chlorofluorocarbons, and ozone formed in smog, into the troposphere at accelerating rates.

A century of industry run on fossil fuels such as oil, gas and coal has also caused problems with the oceans by causing the worlds atmosphere to heat up at an alarming rate. The warning signs have all been sighted. Most of the hottest years on record have occurred in the last decade. Coral reefs are dying as temperatures in the Carribean Sea and the Pacific and Indian oceans reach record highs. North of Greenland, the Arctic ice cap is thinning at a rate of nearly a meter in approximately 10 years time. If no action is taken soon, we can face warming trends 10 to 100 times more rapid than any other in history.