As a global citizen, you know that people around the world share similar environmental concerns. The changing climate is one concern shared by people everywhere. Some Forest Service scientists are interested in studying climate change and its relationship to forests, grasslands, air, and water. You will learn about one of these studies in this monograph. As you know, scientific research is a continual process of discovery. Forest Service scientists are learning much about climate change, but there is still much we do not know. This monograph is part of a collection of articles describing climate change research. Many plants and animals live in annual cycles. They respond to seasonal temperature changes and changes in the length of the day. Some scientists are interested in studying the effect of these seasonal changes on the life cycle of plants and animals. The science that investigates these effects is called phenology (fe nÃl uh je). The science of phenology also investigates the influence of climate on the life cycle of plants and animals. This is important, because many scientists now believe that our climate is changing. In this study, the scientists were interested in understanding how a change in climate might affect the life cycle of a particular species of beetle. Because they could not wait a hundred or more years for the climate to change, the scientists used a computer program to predict what might happen. The scientists contributing to this article are Dr. Jesse Logan and Dr. Barbara Bentz.