Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (15 min)

  • Read Frequently Asked Question 2.1 (How do Human Activities Contribute to Climate Change and How do They Compare with Natural Influences?, pages 135-137) to understand the human contributions to climate change, and how they compare with natural influences. Figure 2 illustrates radiative forcing over the past 300 years and demonstrates the net contribution of human activity to radiative forcing. If you are still unclear about the definition of radiative forcing, Box 1 (page 136) provides a clear description. This resource may take some time to download, but it is used frequently, so please be patient.