Global Climate Change

Is the Climate of the Earth Really Changing?
What is Global Warming?
What is a Greenhouse Gas?
How Does Global Warming Affect Climate?
What can I do to help?

Do the summers in your part of the world seem to be getting hotter and lasting longer?

Have you felt that it rains in your hometown much more than it ever used to, or that the winters are worse now than you ever remembered?
Even if true, these observations cannot be considered evidence of global climate change, because they are measured over too small an area and over too brief a time period. To detect true changes in the climate on a global scale, standardized measurements need to be taken from many places around the world over a period of many, many years.

Is the Climate of the Earth Really Changing?

It is very evident that climate change is a part of nature. What scientists are attempting to determine is if changes in global climate are part of a natural cycle or the result of human activity. Though most of our recorded data go back only 100 years or so, a trend in global climate change appears to have been detected: the temperature seems to be getting warmer. The best estimate, based on a number of scientific studies, is that average global temperatures have increased .54-1.1°ree;F since 1860.

What is Global Warming?

The Earth has warmed and cooled many times before. This fluctuation appears to be a natural cycle. However, for the first time in history, human activity may be the cause of the current global warming trend. The single most important factor for this is a fairly recent increase in certain gases in the atmosphere. These gases are called greenhouse gases because they form a gaseous barrier around the Earth, that traps heat inside, similar to the glass of a greenhouse. How it works is simple. The short, ultraviolet rays from the sun that are able to penetrate the Earth's protective ozone layer are also able to pass through this layer of greenhouse gases. These ultraviolet rays strike the Earth and are absorbed by the land and sea. This energy then radiates back toward the atmosphere in the form of infrared heat waves, which are longer and less able to penetrate the layer of greenhouse gases in the atmosphere. This heat is absorbed by the barrier of greenhouse gases and is not allowed to escape into space, causing the atmosphere, and ultimately the earth below, to warm. In a way, greenhouse gases act like a blanket around the planet, trapping its heat.

What is a Greenhouse Gas?

A greenhouse gas is any gas in the atmosphere that can absorb the infrared heat waves coming from the Earth. It is important to realize that most greenhouse gases are naturally occurring and, in fact, quite beneficial to life on Earth. Without the presence of greenhouse gases, the average temperature of the planet would likely be about -4°ree;F, making Earth a frozen, barren planet similar to Mars. The reason why the planet may be warming now is that people are producing these greenhouse gases in higher amounts than what occurs naturally. The following is a list of greenhouse gases in order of their impact on global warming:

1. Water Vapor (H20)
2. Carbon Dioxide (CO2 )
3. Methane (CH4)
4. Chlorofluorocarbons (CFCs)

How Does Global Warming Affect Climate?

When heat is trapped in the Earth's atmosphere, temperatures on the surface begin to rise. These warming conditions may have profound effects on weather patterns of the world. Wind patterns and oceanic currents may change. Droughts may occur in some regions, while unusually high rainfalls occur in others. Inland wetlands may dry up, decreasing habitat for migrating waterfowl. Further, even a small rise in average global temperatures may have a major impact on sea level. If the expected increase of 2.7-8.1°ree;F occurs over the next 100 years, sea levels will likely rise at least 1.98-11.9 feet in the same time frame. Other possible outcomes include expansion of some coastal and some riverine wetlands, especially the large flat water deltas like the Nile and the Amazon. Many other global climate changes may happen as well, but lack of data makes predictions difficult.

What can I do to help?

Do whatever you can to reduce energy use and pollution. For example, instead of driving a car, take public transportation (trains or buses), walk, or ride a bicycle to school or work. Replace incandescent light bulbs with energy efficient compact fluorescent ones. Urge public officials to promote renewable energy and energy efficiency standards. Purchase energy efficient appliances. Recycle, reduce and reuse.