The growing number of published works dedicated to global environmental change leads to the realization that protection of the natural environment has become an urgent problem. The question of working out principles of co evolution of man and nature is being posed with ever-increasing persistence. Scientists in many countries are attempting to find ways of formulating laws governing human processes acting on the environment. Numerous national and international programs regarding biosphere and climate studies contribute to the quest for means of resolving the conflict between human society and nature. However, attempts to find efficient methods of regulating human activity on a global scale encounter principal difficulties. The major difficulty is the lack of an adequate knowledge base pertaining to climatic and biospheric processes as wen as the largely incomplete state of the databases concerning global processes occurring in the atmosphere, in the ocean, and on land. Another difficulty is the inability of modern science to formulate the requirements which must be met by the global databases necessary for reliable evaluation of the state of the environ ment and fore casting its development for sufficiently long time intervals."

This is a timely book in light of increasing concern over global warming and environmental pollution. It describes a simulation system based on sets of computer algorithms for comprehensive analysis of data from global and regional monitoring systems. Chapters in the theoretical part of the book contain descriptions of rigorous algorithms and global environmental models. The applied part considers specific problems of environmental dynamics in areas such as the Arctic and the Caspian-Aral Seas. The purpose of this book is to develop a universal information technology to estimate the state of environmental subsystems functioning under various climatic and anthropogenic conditions. Applied mathematicians, hydrologists, geophysicists, socio-economists and other researchers of global change will find a wealth of information in this book.

Terrorist use of radioactive nuclear materials is a serious threat for mass destruction or disruption of civil and military activities. Most worrisome is the use of nuclear devices to cause massive casualties to people and damage to structures. Fortunately, the procurement of adequate material and the engineering design, construction, and transportation and triggering of a nuclear weapon are all difficult problems for terrorist organizations. More likely is a device that combines radioactive materials with conventional explosives to make a radiological dispersion device, commonly called a "dirty bomb." The procurement of nuclear materials for this purpose, the construction of the bomb and its use are all easier than for a nuclear weapon. Fortunately, the effects from the use of a radiological weapon would be much smaller than from a nuclear device, although they could still be very disruptive. Thus, it is important to detect the transport of nuclear weapons and radiological dispersion devices and the materials for their construction. These materials emit gamma rays or neutrons, which can be detected to show the presence and amounts of such materials.