The extent to which weather and climate are being inadvertently modified by large-scale human activities is a matter which is arousing much-deserved concern. It is also a matter about which very little quantitative information exists. For the past several years, the Atmospheric Physics and Chemistry Laboratory has concentrated a substantial share of its modest resources on the instigation of a program of data collection and analysis which has the objective of providing accurate and quantitative facts on: (a) the amounts of anthropogenic contaminants in the atmosphere; (b) the interaction of these contaminants with the natural atmospheric constituents; and (c) the changes in weather and climate resulting from the physical and chemical effects of the contaminants.

The growing problem of changing environmental conditions caused by climate destabilization is well recognized as one of the defining issues of our time. The root problem is greenhouse gas emissions, and the fundamental solution is curbing those emissions. Climate geoengineering has often been considered to be a "last-ditch" response to climate change, to be used only if climate change damage should produce extreme hardship. Although the likelihood of eventually needing to resort to these efforts grows with every year of inaction on emissions control, there is a lack of information on these ways of potentially intervening in the climate system. As one of a two-book report, this volume of Climate Intervention discusses albedo modification - changing the fraction of incoming solar radiation that reaches the surface. This approach would deliberately modify the energy budget of Earth to produce a cooling designed to compensate for some of the effects of warming associated with greenhouse gas increases. The prospect of large-scale albedo modification raises political and governance issues at national and global levels, as well as ethical concerns. Climate Intervention: Reflecting Sunlight to Cool Earth discusses some of the social, political, and legal issues surrounding these proposed techniques. It is far easier to modify Earth's albedo than to determine whether it should be done or what the consequences might be of such an action. One serious concern is that such an action could be unilaterally undertaken by a small nation or smaller entity for its own benefit without international sanction and regardless of international consequences. Transparency in discussing this subject is critical. In the spirit of that transparency, Climate Intervention: Reflecting Sunlight to Cool Earth was based on peer-reviewed literature and the judgments of the authoring committee; no new research was done as part of this study and all data and information used are from entirely open sources. By helping to bring light to this topic area, this book will help leaders to be far more knowledgeable about the consequences of albedo modification approaches before they face a decision whether or not to use them.

As the world's population rises, there is increasing evidence that human activities are having a significant impact on the weather and climate, from a local to global scale. Human Impacts on Weather and Climate is a non-mathematical presentation of the basic physical concepts of how human activity may affect weather and climate. This book assesses the current hypotheses, and examines whether the impacts are measurable. Included are: critical evaluations of the scientific status of weather modification by cloud seeding; human impacts on regional weather and climate; and human impacts on global climate, including the greenhouse gas hypothesis. Discussions also focus on the modern philosophy of science and its application to determining human impacts on weather and climate. Human Impacts on Weather and Climate will be invaluable for upper-division undergraduate and graduate courses in meteorology, geophysics, and earth and atmospheric science, as well as for policymakers and readers with an interest in how humans are affecting the atmosphere. An extensive reference list is included.

Natural and human-induced changes in Earth's interior, land surface, biosphere, atmosphere, and oceans affect all aspects of life. Understanding these changes requires a range of observations acquired from land-, sea-, air-, and space-based platforms. To assist NASA, NOAA, and USGS in developing these tools, the NRC was asked to carry out a "decadal strategy" survey of Earth science and applications from space that would develop the key scientific questions on which to focus Earth and environmental observations in the period 2005-2015 and beyond, and present a prioritized list of space programs, missions, and supporting activities to address these questions. This report presents a vision for the Earth science program; an analysis of the existing Earth Observing System and recommendations to help restore its capabilities; an assessment of and recommendations for new observations and missions for the next decade; an examination of and recommendations for effective application of those observations; and an analysis of how best to sustain that observation and applications system.