For research on climate change, past is key to future



One of the major challenges for predicting future climate change is determining the specific causes of past and present changes. Greenhouse gases are not alone in influencing climate; changes in solar irradiance and major volcanic eruptions also play important roles. Recent research findings complement and reinforce evidence for human-induced warming based on theory, computer models, and the growing number of observations that claim to detect a “fingerprint” signal of the greenhouse effect. They do not deny the importance of solar influences on climate and especially cloud variability, but they do point to a broader picture.