Most scientists agree that human activities have been responsible for increased levels of greenhouse gases in the atmosphere. Activities such as using carbon-based fuels (gas, oil, coal), land use changes (deforestation) and industrial smokestacks have led to increased variations in global temperatures, rainfall and other weather patterns. The collective effects of these variations are unpredictable, and are best known as climate change.
In response, industrial and business practices have been developed to help remove as much carbon from the atmosphere as is put in. These practices mimic and complement the workings of the natural carbon cycle and are known as carbon sequestration. Planting trees, preserving soil, and stimulating plankton growth are examples of natural methods of carbon sequestration.
Carbon credits are a business mechanism whereby polluting businesses and consumers can offset their carbon emissions by purchasing credits, generated by carbon sequestering practices of another business. By buying credits, polluters aim to create a net sum of zero emissions, essentially becoming carbon neutral.
