By burning fossil fuels such as coal, gas and oil, and clearing forests, we have dramatically increased the amount of carbon dioxide in the Earth's atmosphere and temperatures are rising.

The vast majority of scientists agree that global warming is real, its already happening, and that it is the result of our activities and not a natural occurrence.

The evidence is overwhelming and undeniable.

We're already seeing changes. Glaciers are melting, plants and animals are being forced from their natural habitat, and the number of severe storms and droughts is increasing. The number of Category 4 and 5 hurricanes has almost doubled in the last 30 years. Malaria has spread to higher altitudes in places like the Columbian Andes, 7000 feet above sea level.

The flow of ice from glaciers in Greenland has more than doubled over the past decade. At least 279 species of plants and animals are already responding to global warming, moving closer to the poles.