The Causes of Global Climate Change

The Earth has been going through natural periodic cycles of warming and cooling since it's creation. Climate change is not a new concept, but this is the first time sophisticated society will have to deal with the effects. Human activity does not cause global warming; rather humans aide the natural processes. Lets look at some the most common factors leading to global warming.

All of the Earth's heat and life is derived from the radiation received from the Sun. The Earth's angle of rotation leads to an uneven distribution of the energy at the surface. Receiving more direct cycles (Incoming Solar Radiation) at the equator leads to a surplus of energy (heat). In an attempt to balance this, heat is transferred to the poles where there is a deficit. The transfer takes place in the form of winds and storms, as well as ocean currents. If the solar output were to increase, more energy would be received by Earth, leading to a greater exchange of heat. What would cause the solar output to increase? Surely humans couldn't be blamed for that. Most people have heard of the term sunspots. These areas of substantially cooler temperatures (about 1300 Degrees K) appear naturally on the Sun's surface. The appearance of sunspots are defined by an 11 year cycle. It has also been noted that an increase in the sunspot number can lead to warmer temperatures on Earth. This is due to a complicated inverse relationship between sunspots and galactic cosmic rays, in which GCRs aide to cool the planet. During the 17th century, there was an absence of sunspots. This has been named the Maunder minimum, which coincides a period of about 250 years of colder global temperatures. Currently, sunspot activity is on the rise as a part of the natural cycle. Predictions place this solar peak as one of the highest on history, which could lead to warmer temperatures on Earth.

Another natural process that could lead to climatic changes are the periodical changes in Sea Surface Temperatures (SST). The El Nino Southern Oscillation (ENSO) is a recorded shift in the location of warmer waters in the Pacific Ocean. This periodic change has massive global affects on precipitation and wind patterns, as well as ecological affects on the marine wildlife in the affected area. The ocean currents are an essential part of energy transfer on this planet. IF this system is altered, there could be a resulting increase in temperature due to excess energy in one location. Slight changes that occur with the ENSO can have devastating affects such as drought and flooding. There are other ocean oscillations as well that affect global climate, such as the Pacific Decadal Oscillation, and the North Atlantic Oscillation. All of these systems are connected and have great potentials in influencing global conditions.

While not the cause of global warming, human activity should be discussed. Increased emissions of green house gases such as carbon dioxide aide in warming the atmosphere. Not only to chemical reactions in the upper atmosphere lead to warming, but radiation that would otherwise be reflected away from Earth is trapped. Also harmful aerosols that are released as a by product of factories can lead to health affects, as well as the destruction of the ozone layer that limits harmful radiation.

As for melting ice caps, this can be describes as both a cause and a product of global warming. A small increase in temperature can lead to melting ice, reducing the great polar ice caps. As a result, less sunlight is reflected, and more radiation is absorbed. This causes the poles to warm and in turn melt more ice.

There is also the possibility all these changes could lead to an unexpected outcome of cooler temperatures. If the planet is warmer, there will be more rising air. This will lead to more condensation and cloud formation. With more clouds comes more radiation reflected, leading to a cooler Earth (global dimming theory). Also, the addition of fresh water as a result of melting polar ice can disrupt delicate ocean systems. These currents bring warm water to regions that would otherwise be a lot colder (Europe for example is a similar latitude to Northern Canada, but has similar climate to North America). If this system shuts down, the Earth could be sent into an Ice Age.

While it is debatable the exact causes of global warming and what the outcome will be, it is obvious there are changes occurring. These changes have occurred in the past, and the Earth has survived. Now the question becomes will humans be able to do the same.