Science does not tell us fact. Instead, it tells us what is collectively agreed upon to be the best theory of fact until a better theory should come along. For example, we don’t know for certain that the sun is hot, but we have overwhelming evidence that leads us to believe that it is. However, should someone come out with a theory, backed by more compelling evidence than the previous theory, that the sun is in fact cold, then we would decide to be fact that the sun is cold.

Similarly, in the issue of climate change, science does not tell us that it is fact that humans play a major role in recent and future climate change due to the release of carbon dioxide and other greenhouse gases into the atmosphere. Instead, the majority of the scientific evidence—the most compelling theory—suggests that this is by far the most likely case.

Do you know your science?

This section and its constituent subsections are dedicated to the fundamental scientific evidence for anthropogenic global warming. This section will be added to as needed or requested. If you see any problems/errors (or disputes), please email Dan (drchavas at wisc dot edu).

Introduction: the spirit of science

Choose from one of the links found below, or use the link bar on the left side of the page.

Earth is warming

Greenhouse effect

Climate history

Climate models

Global dimming?

Other evidence