Global Warming is the average increase in temperature of a biosphere. Scientists blame human activity as the primary cause of the earth's warming. One of the articles I read provided some shocking statistics as to the extent of global warming. Last century the average land surface temperature increased over 1 degree Fahrenheit. Ten of the warmest years of the twentieth century occurred within the past 15 years. Carbon Dioxide concentration in the atmosphere has increased over 30% since the Industrial Revolution. The average American emits over 6.6 tons of greenhouse gases a year! Scientists predict that by 2100 the average world temperature will increase from 2 to 7 degrees Fahrenheit. During the past 100 years sea levels across the world have increased 4-10 inches. Throughout Earth's history climates have been changing, so some say it is difficult to ascertain whether temperature fluctuations are a result of human activity, natural causes, or a combination of the two...