ENVIRONMENTAL CHANGE | ||
| The Egyptian Journal of Environmental Change | ||
| Contributors, Volume 1, Issue 1, October 2009, Pages 1-2 PDF (1.78 M) | ||
| DOI: 10.21608/ejec.2009.96541 | ||
| Abstract | ||
| The environment of the Earth is the world’s continental shelves were for ever changing. Changes occur at alternately exposed and flooded. a whole array of time scales and, for All these natural changes have had a example, over geological time, the major impact on the fortunes of human Earth has witnessed both greenhouse societies and have played a role in such and icehouse conditions. Even over matters as migrations, the collapse the last few millions of years, we have of civilizations, and the origins of experienced repeated lurches from glacial agriculture. to interglacial conditions, while over Now, however, humans are having an the last ten thousand or so years of the increasingly important role in promoting Holocene we have had neoglaciations environmental change. On the one hand, (such as the Little Ice Age), pluvials in changes in land cover are modifying rates the Sahara, and several phases when of erosion and runoff , while on the other conditions have been warmer than today the emission of a cocktail of greenhouse (as in early Medieval times). At a shorter gases into the atmosphere is starting to time scale there have been fluctuations cause global climate change. In coming at the decadal scale, including ENSO, decades it is likely that, for example, the Pacific Decadal Oscillation, and the many glaciers will melt, permafrost North Atlantic Oscillation. In addition to will decay, sea levels will rise, rainfall appreciating that there have been changes regimes may become more extreme, and at a whole range of scales, it is important desert dunes may become more active. to recognize that some changes have been Hazards such as droughts and floods may abrupt and also that the degree of change change in intensity. has sometimes been very substantial. Environmental changes, both natural For example, around 9000 years ago, and anthropogenic, and in the past and much of the currently hyperarid Sahara in the future, are now a major concern was a savanna landscape with large lakes for many academic disciplines, and so and some major rivers. Conversely, at the appearance of this new journal is the maximum of the last glacial, around extremely timely and significant. 20, 000 years ago, many parts of the currently humid tropics were probably Andrew Goudie, University of Oxford, UK. | ||
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