Almost every day, some how climate change and global warming hits the headlines. For most of us, this is very confusing. Some people consider every storm, drought, heat wave and record temperature further evidence for global warming; others dismiss these same events as natural climate variation. Isn't everyone looking at the same data? How can the same facts be interpreted in such different ways?
When the interpretation of scientific date makes it interpretive that we change the ways we create and use energy, the origin of these data becomes controversial and politically charged. Before we undertake any action that will have a long-term impact on society, we need to understand how and why global climate changes. The geological record shows us that climate change is a normal part of Earth's history, and while most scientists conclude that recent changes in global temperature and climate are due to the emission of human-made heat-trapping greenhouse gases, a small but vocal minority disagrees.
Climate change is both natural and normal, and it is driven by many different factors acting over different timescales. So far, the evidence from field observations, the historical temperature record, and climate models suggests that recent climate change is a consequence of both human and natural forcing. There is strong evidence based on sound data that the climate is changing, but a few scientists and a significant percentage of the general public in the United States still doubt that most of this change is due to human activity. At a time of prolonged global economic recession, they argue that we should not divert precious resources to stop change that will be mild and natural.