الصفحة 1
الصفحة 1
Nitrogen Cycling in the Americas : Natural and Anthropogenic Influences and Controls
The rate of creation of reactive nitrogen (NR) on the earth has dramatically increased in the last half century mainly due to the production of N-fertilizer through the Haber-Bosch process, fossil fuel combustion, and the cultivation of plants that fix N from the atmosphere. The anthropogenic production of NR has been especially high in developed countries of the temperate zone, such as the USA and Canada, where severe eutrophication of estuaries and coastal zones, acidification of lakes and streams, loss of biodiversity, and reduced forest productivity have become common environmental problems associated with increasing nitrogen loads to ecosystems. This book presents a series of studies from across the Americas whose aim is to highlight key natural processes that control nitrogen cycling as well as discuss the main anthropogenic influences on the nitrogen cycle in both the tropical and temperate regions of the Americas.
Environmental Risk Assessment : Quantitative Measures, Anthropogenic Influences, Human Impact
The world is a dirty place and getting dirtier all the time. The reasons for this ever-increasing lack of cleanliness are not hard to find, being basically caused by the actions of the six billion people who inhabit the planet. The needs of the people for air, water, food, housing, clothing, heating, materials, oil, gas, minerals, metals, chemicals, and so forth have, over the centuries, given rise to a variety of environmental problems that have been exacerbated or been newly created by the industrialization of the world, the increase in population, and the increase in longevity of the population. The costs of cleaning even fractions of the known environmental problems are truly enormous, as detailed in the volume Environmental Risk Analysis (I. Lerche and E. Paleologos, 2001, McGraw-Hill). The chances of causing new environmental problems, and their associated costs of clean up, are equally challenging in terms of anthropogenic influences and also of the natural environmental problems that can be triggered by humanity.
