The Biosphere At Risk

In the Earth's atmosphere, the warming effect of "greenhouse gases" is an undisputed phenomenon. Without it, the globe would be covered in ice. For thousands of years, a fairly constant level of greenhouse gases created the moderate environment in which civilisation evolved.

In the 21 st century, human activity could cause a doubling of these heat-trapping gases. In geological time, such change is sudden and with little precedent.

In the next fifty years, the global population will use more energy than the total consumed in all previous history. Humanity faces a future of radical change - either in the way we produce energy or in the health of our planet.

Most energy today comes from burning fossil fuel to make electricity, run factories, power vehicles and heat homes. Fossil resources - coal, oil and natural gas - are being consumed so fast as to be largely exhausted during the 21st century.

With all fossil energy, waste products are dispersed directly into the air. Much of this waste takes the form of greenhouse gases such as carbon dioxide. Each year fossil fuel waste adds 25 billion tonnes of carbon dioxide to the atmosphere. This equates to 70 million tonnes each day - or 800 tonnes a second.

To analyze the effects of the rapid build-up of heat-trapping gases, world experts are cooperating though the UN's Intergovernmental Panel on Climate Change. The dynamics of climate change are complex and subject to competing theories. But scientists agree that increased greenhouse gases are causing the Earth to capture more solar heat. For most climate scientists, man-made greenhouse gases explain why the decade of 2000-2009 was the warmest on instrumental record of global surface temperature (since 1850).

Climate experts are virtually unanimous in warning that the build-up of the greenhouse gases could, in the century ahead, become catastrophic. Rising sea levels, extreme temperatures, violent storms, devastating droughts and the spread of disease would destroy food production and human habitability in many regions. These experts warn that radical climate change could eventually destabilize the entire biosphere.

All nations are involved in climate change - in both cause and effect. North Americans release carbon dioxide into the atmosphere at a daily rate of 54 kilograms - or 120 pounds - per person. In Europe and Japan, daily per capita emissions are more than 23 kilograms - or 50 pounds. In fast-developing China, with 1.4 billion people, the emissions level already exceeds 6 kilograms - or 13 pounds - for each person each day.

Further Reading
Global Warming - Science
Global Warming - Policy Responses
Responding to Global Climate Change: The Sustainable Energy