What is Climate Change?

The world's climate has always varied naturally. Scientists believe, however, that a new kind of climate change is now underway. Its impacts on people and ecosystems are to be drastic. Levels of carbon dioxide and other 'greenhouse gases' in the atmosphere have risen steeply since the industrial revolution. Concentrations have increased mainly because of the use of fossil fuels, deforestation and other human activities, spurred on by economic and population growth. Like a blanket around the planet, greenhouse gases stop the energy escaping from the Earth's surface and atmosphere. If levels rise too high, excessive warming can distort natural patterns of climate.

In the past the Earth's climate has changed as a result of natural causes in our atmosphere.

The changes we are witnessing and those that are predicted are largely due to human behavior: we are burning fossil fuels, and heating up the planet at the same time. We blow exponential amounts of carbon dioxide (CO₂) into the atmosphere every year - more than 29 billion tones, and this warms the globe.

Since the Industrial Revolution, humans have been burning fossil fuels on a massive scale. We use this energy, almost without care for the consequences, to run vehicles, heat homes, conduct business, and power factories.

Burning fossil fuels releases carbon dioxide stored millions of years ago as oil, coal or natural gas. In the last 200 years we have burned a large part of these stores, resulting in an increase in CO₂ in our atmosphere. Deforestation also releases CO₂ stored in trees and in the soil.