The National Academy of Sciences, a private organization of top scientists that advises the U.S. government on scientific matters, reported on June 22, 2006, that the "recent warmth is unprecedented for at least the last 400 years and potentially the last several millennia" and that "human activities are responsible for much of the recent warming".
The report goes on to say that from the start of the 20th century, there were sharp rises in the "greenhouse" gases, carbon dioxide and methane. These two gases are believed to be the main contributors to global warming, by trapping heat in the Earth's atmosphere, similar to the way that a windshield traps heat in a car.
What is producing enough greenhouse gases to change the climate of our planet? Since the industrial age began, factories, power plants, and cars have burned coal and gasoline. Spitting out an endless stream of carbon dioxide. We produce millions of pounds of methane by allowing our trash to decompose in landfills and from agricultural sources like cattle and fertilizer.
Scientists all over the world agree that humans are the cause of global warming and that it could have catastrophic effects. It is important for all countries to reduce emissions of carbon dioxide and other greenhouse gases now, to limit the future effects of global warming.
As a society, we must break our dependency on fuels that cause pollution by supporting clean, renewable energy sources. Each of us can slow global warming by reducing the amount of energy we use and the pollution we produce as individuals every day.
The Impact of Global Warming
What effects will global warming have on the Earth and its inhabitants in the future? Are there any effects from global warming visible now?
Due to the enormous complexity of the atmosphere, the most useful tools for gauging future changes are 'climate models'. These are computer programs which simulate the climate's behavior.
Climate models are constantly improving based on both our understanding and the increase in computer power. However, climate models are just simulations and they can only be as good as the knowledge and skill of the people who create them. With that in mind, here are what some scientists are predicting as the potential consequences of global warming.
Earth
A number of geologists suggest that glacial melting due to climate change will release pressures in the Earth's crust, causing extreme geological events such as earthquakes, tsunamis and volcanic eruptions.
Wind
The number of powerful and dangerous hurricanes could increase. Warmer water in the oceans pumps more energy into tropical storms, making them more intense and potentially more destructive.
Fire
Heat waves could be more frequent and severe. This could cause more heat related deaths. Warmer and dryer conditions could bring drought conditions and increase the risk of wildfires.