The consequences of stresses, individually and in concert, need to be better understood. Climate change manifests itself on a regional scale, and the magnitude of change and impacts varies by region. Providing decisionmakers with the information they need requires research and modeling of global environmental change on much finer spatial scales and across a wider range of timescales than is being done today. Historically the planet has experienced wide ranges of environmental and climate conditions, from ice ages to tropical-like climates in the polar regions, with dramatic changes in patterns of temperature and precipitation. The transitions between these various conditions are not always smooth and gradual, but rather can be abrupt and very rapid.
Climate change resulting from greenhouse gas emissions poses the potential for abrupt change.
Such assessments are essential for making scientific information useful for decisionmakers. The real significance of these objectives is seen most clearly when they are taken together. How several major Earth subsystems work is relatively well understood, and there is some degree of predictability in their behaviors. Researchers are poised to take a giant step toward a whole-system understanding of the Earth s environment and application of this understanding to societal needs. This process, although it is not yet complete, has guided the creation of this implementation plan.