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Environment                  Present
Africa
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 Some of the biggest earthquakes ever to rock the planet have occurred in the last 60 years. In 1960 the world's strongest recorded quake--9.5 on the Richter scale--devastated Chile, generating a 300-foot tsunami that wiped out entire villages there, and then raced across the Pacific to kill 61 people in Hawaii. A violent earthquake measuring 9.0 on the Richter scale hit Assam in northeast India in. 1950, and a 9.2 quake shook Prince William Sound in Alaska in 1964, killing 25 people and generating a tsunami that took another 110 lives. In 1976 China, prone to large, destructive earthquakes, suffered the most devastating earthquake to hit that nation in the twentieth century, killing an estimated 600,000 people in the Tang Shan province. The temblor leveled a 20-square-mile section of the city of Haicheng. A massive quake in Mexico City in 1985 killed 10,000; one in Armenia in 1988 killed 25,000. Iran; Japan; Taiwan; El Salvador; and Oakland, California, and Seattle here in the United States have all been struck by earthquakes in the recent past. (69)

A reconstruction of mean surface temperature in the northern hemisphere over the past two millennia based on high-resolution proxy temperature data (white curve), which retain millennial-scale variability, together with the instrumental temperature record for the northern hemisphere since 1856 (black curve). This combination indicates that late twentieth-century warmth is unprecedented for at least roughly the past two millennia for the northern hemisphere. If the 'hockey stick' is an accurate assessment of climatic variations during the past two millennia, it has profound implications. Because the recent warming is so much more marked than earlier natural fluctuations, such as the Medieval Climatic Optimum and the Little Ice Age, it implies that the gentle long-term downward trend, which was the most obvious natural variation, was reversed dramatically around the end of the nineteenth century, as a result of human activities. If true, it would appear that current efforts to moderate our impact on the climate are, to say the least, a bit late. If...the hockey stick is correct, then the real issue will be how we adapt to what appears to be an inexorable change while, at the same time, not making matters worse. (145)

...if the climate returned to the chaotic behaviour at the end of the last ice age, agriculture would only be possible in the most blessed parts of the world: modern-day refugia. The examples of the development of agriculture in the mid-Holocene in southern Mesopotamia and the Nile Valley reinforce this point. They show that even in a climatically benign period, it was only those places with the most reliable supplies of water that were capable of sustaining agriculture for centuries or millennia. Although agriculture has thrived in temperate latitudes for several millennia, the prospect of much more variable weather would pose a major challenge to maintaining modern yields. (145)

According to reports published in Nature and New Scientist, the last geomagnetic reversal was completed just 12,400 years ago - during the eleventh millennium BC. Scientists expect the next reversal of the earth's magnetic poles to occur around AD 2030. (152)

Particularly troubling is the fact that a remorseless decay of the earth's magnetic field has been underway during the last 2000 years and has been rapidly accelerating during the past century. Indeed, scientists now expect the field's energy to drop to zero, initiating a rapid north-south magnetic 'pole reversal' before the year 2300. (161)

Africa

 

Southwest Asia

 

Egypt

 The modern Sahara desert is now nearly lifeless, with populations limited to the hardiest of desert plants and animals. The once semiarid habitable environment of southern Egypt and northern Sudan has dried up since 4500 BC, and is now dominated by the wind. (70)

Indus Valley

 

China

 

Europe

 

South America

 In modern times, the Altiplano is subject to prolonged and severe droughts punctuated by seasons of disastrously heavy rains that cause flooding. The air is thin and does not retain much moisture or heat. Daily, temperatures show wide fluctuations and frosts can occur any time I of year, making agriculture a constant struggle. Hail and winds also impact crops and only highly adapted, hardy, short-season tubers and grains can be grown. Agronomists say that just 20 percent of the Andean food crops are grown above 10,000 feet today. (69)

Mesoamerica

 

North America

 In some prehistoric periods the Southwest was wetter than it is today, but for most of the last ten thousand years the Southwest has usually been at least as hot and dry as it is today, and there were short periods of extreme drought. (53)

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