The next question that arises is, why to study climate?

The reason studying climate and a changing climate is important, is that will affect people around the world. Rising global temperatures are expected to raise sea levels, and change precipitation and other local climate conditions. Changing regional climate could alter forests, crop yields, and water supplies. It could also affect human health, animals, and many types of ecosystems. Deserts may expand into existing rangelands, and features of some of our National Parks and National Forests may be permanently altered.

An example of a Monthly Mean Outgoing Longwave Radiation (OLR)

 product produced from NOAA polar-orbiter satellite data, which is frequently

    used to study global climate change. Credits: NOAA

The National Academy of Sciences, a lead scientific body in the U.S., determined that the Earth's surface temperature has risen by about 1 degree Fahrenheit in the past century, with accelerated warming during the past two decades. There is new and stronger evidence that most of the warming over the last 50 years is attributable to human activities. Yet, there is still some debate about the role of natural cycles and processes.

Human activities have altered the chemical composition of the atmosphere through the buildup of greenhouse gases – primarily carbon dioxide, methane, and nitrous oxide. The heat-trapping property of these gases is undisputed although certainties exist about exactly how Earth's climate responds to them. According to the U.S. Climate Change Science Program (http://www.climatescience.gov), factors such as aerosols, land use change and others may play important roles in climate change, but their influence is highly uncertain at the present time.