Studying global change

The global ecosystem is composed of an almost infinite number of interacting sub systems ranging in scale from global to very local. These systems exist in a state of dynamic balance that is slowly but constantly changing at a rate that is consistent with the geologic time scale. Global change research examines the consequences of imposing rapid change on this balanced, or very slowly changing set of systems. It is concerned with how global systems such as climate, the atmosphere, and the oceans will adjust in response to these changes. It is also concerned with how large regional systems such as tropical rainforests, coastal areas, lakes and deserts will react both to rapid changes in global systems, and to the direct effect of human induced change. Finally, the field of global change is concerned with how societies and economies will be affected by these changes.

Our planet is roughly 4.5 billion years old. Humans have been on this earth for less than two million years, but it is only in the past 200 years that we have had any significant and large scale impact upon the global natural environment. Environmental conditions became degraded within human settlements and around the early factories of the industrial revolution, but away from these places, the ecosystem's capacity to purify and repair itself was sufficient to contain the extent of most human impact. However, since World War II this situation has changed dramatically. Exponential growth in human population, rapid technological advances, and significant increases in both material and energy consumption have put humans in a position where their daily activities are altering entire global systems such as the atmosphere and the oceans at a rate that has never before been experienced on this planet. It is the unprecedented rate of this change that is largely responsible for what we are calling global change.