Many nations conduct research and engage in other scientific activities on our frozen continentâ€"Antarctica. Each year the U.S. National Committee for the Scientific Committee on Antarctic Research (SCAR) compiles a book that includes these nations' reports of scientific pursuits undertaken by their citizens in Antarctica during the previous austral summer and of planned activities for the next season. This book details the activities that occurred in 1990 and is of particular value to policymakers and scientists throughout the world who are planning Antarctic programs.

This volume reflects the current state of scientific knowledge about natural climate variability on decade-to-century time scales. It covers a wide range of relevant subjects, including the characteristics of the atmosphere and ocean environments as well as the methods used to describe and analyze them, such as proxy data and numerical models. They clearly demonstrate the range, persistence, and magnitude of climate variability as represented by many different indicators. Not only do natural climate variations have important socioeconomic effects, but they must be better understood before possible anthropogenic effects (from greenhouse gas emissions, for instance) can be evaluated. A topical essay introduces each of the disciplines represented, providing the nonscientist with a perspective on the field and linking the papers to the larger issues in climate research. In its conclusions section, the book evaluates progress in the different areas and makes recommendations for the direction and conduct of future climate research. This book, while consisting of technical papers, is also accessible to the interested layperson.