[1] A suite of climate change indices derived from daily temperature and precipitation data, with a primary focus on extreme events, were computed and analyzed. By setting an exact formula for each index and using specially designed software, analyses done in different countries have been combined seamlessly. This has enabled the presentation of the most up-to-date and comprehensive global picture of trends in extreme temperature and precipitation indices using results from a number of workshops held in data-sparse regions and high-quality station data supplied by numerous scientists world wide. Seasonal and annual indices for the period 1951-2003 were gridded. Trends in the gridded fields were computed and tested for statistical significance. Results showed widespread significant changes in temperature extremes associated with warming, especially for those indices derived from daily minimum temperature. Over 70% of the global land area sampled showed a significant decrease in the annual occurrence of cold nights and a significant increase in the annual occurrence of warm nights. Some regions experienced a more than doubling of these indices. This implies a positive shift in the distribution of daily minimum temperature throughout the globe. Daily maximum temperature indices showed similar changes but with smaller magnitudes. Precipitation changes showed a widespread and significant increase, but the changes are much less spatially coherent compared with temperature change. Probability distributions of indices derived from approximately 200 temperature and 600 precipitation stations, with nearcomplete data for 1901-2003 and covering a very large region of the Northern Hemisphere midlatitudes (and parts of Australia for precipitation) were analyzed for the periods 1901-1950, 1951-1978 and 1979-2003. Results indicate a significant warming throughout the 20th century. Differences in temperature indices distributions are particularly pronounced between the most recent two periods and for those indices related to minimum temperature. An analysis of those indices for which seasonal time series are available shows that these changes occur for all seasons although they are generally least pronounced for September to November. Precipitation indices show a tendency toward wetter conditions throughout the 20th century.

It is thought that a significant factor in the fall of the Egyptian Old Kingdom was the occurrence of a number of lower than average inundation events that led to a decline in agricultural output, causing a famine that undermined the authority of the government. However, very little consideration has been given to how a lesser volume of water may have impacted upon the Nile itself. This composition investigates the potential for ecological change that may have developed as a consequence of a lower river. Since a lower river exhibits less force, its physical properties should change, which would in turn alter the chemical and biological factors that are expressed. A low Nile should therefore have resulted in changes to the distribution and abundance of plant life along the river. Four plants characteristic to Pharaonic times were investigated to see how they may have responded. Papyrus and Phragmites are suggested as plants that would benefit from a situation where the nutrients remained within the river, whereas Typha and Lotus display characteristic that benefit less when the river retains nutrients that would have normally been lost to the surrounding landscape.

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