Glaobal Warming essays

Glaobal Warming essays Scientists have predicted that the earths climate will change because human activities are altering the chemical composition of the atmosphere through the buildup of greenhouse gases primarily carbon dioxide, methane, and nitrous oxide. The global warming property of these gases is undisputed although uncertainty exists about exactly how earths climate responds to them. Like many fields of scientific study, there are uncertainties associated with the science of global warming. This does not imply that all things are equally uncertain. Some aspects of the science of global warming are based on well-known physical laws and documented trends, while other aspects range from near certainty to big unknowns. Global warming is not as serious of a threat as scientists are stating. There is no doubt that the atmospheric buildup of greenhouse gases is largely the result of human activities. By increasing the levels of greenhouse gases in the atmosphere, human activities are strengthening Earths natural greenhouse effect. Figuring out to what extent the human-induced accumulation of greenhouse gases since pre-industrial times is responsible for the global warming trend is not easy though. This is because other factors, both natural and human, affect our planets temperature. Scientific understanding of these other factorsmost notably natural climate variations, cooling effects of atmospheric particles such as sulfates, changes in the suns energy, and the cooling effects of pollutant aerosolsremains incomplete. To project future climate patterns, scientists use computer simulations of the interactions among land, air, water, ice, and sunlight. These general circulation models, or GCMs, consist of equations representing the known laws of atmospheric physics and ocean circulation (Monastersky 1). A perfect model, if given enough information about conditions on earth several hundred ye...

Ancient Egypt essays

Ancient Egypt essays I first began my research at the Smithsonian Institute National Museum of Natural History. Ancient Egyptian history covers a period of over three thousand years. Most modern countries histories are only hundreds of years old. Only China can come anywhere near this in term of historical continuity. Egyptian culture declined and disappeared nearly two thousand years ago. The last trace of this culture ceased to exist in AD 391 when the Byzantine Emperor Theodosius I closed all pagan temples throughout the Roman Empire. It wasnt until Napoleon's invasion of Egypt in 1798 that the marvelous artifacts of the Egyptians were seen in Europe and their ancient culture began to awaken from its long slumber. Daily life in ancient Egypt flourished around the Nile and the fertile land along its banks. The yearly flooding of the Nile enriched the soil and brought good harvests and wealth to the land. The people of ancient Egypt built mud brick homes in villages and in the country. They grew some of their own food and traded in the villages for the food and goods they could not produce. Most ancient Egyptians worked as farmers, field hands, scribes and craftsmen. There were however a small group of people who were nobles. The ancient Egyptians thought of Egypt as being divided into two types of land, the 'black land' and the 'red land'. The 'black land' was the fertile land on the banks of the Nile. The ancient Egyptians used this land for growing their crops. This was the only land in ancient Egypt that could be farmed because a layer of rich, black silt was deposited there every year after the Nile flooded. The 'red land' was the barren desert that protected Egypt on two sides. These deserts separated ancient Egypt from neighboring countries and invading armies. They also provided the ancient Egyptians with a source for precious metals and semi-precious stones. The ancient Egyptians believed that mummifying a person's body after...