Climate change is a change in the "average weather" that a given region experiences. Average weather includes all the features we associate with the weather such as temperature, wind patterns and precipitation. When we speak of climate change on a global scale, we are referring to changes in the climate of the Earth as a whole. The rate and magnitude of global climate changes over the long term have many implications for natural ecosystems.
A natural system known as the "greenhouse effect" regulates the temperature on earth. Human activities have the potential to disrupt the balance of this system. As human societies adopt increasingly sophisticated and mechanized lifestyles, the amounts of heat-trapping gases in the atmosphere have been increased. By increasing the amount of these gases (fossil fuels), humankind has enhanced the warming capability of the natural greenhouse effect. It is the human-induced enhanced greenhouse effect that causes environmental concern.
It has the potential to warm the planet at a rate that has never been experienced in human history.
Changes in the climate are not only due to humans, but also trough nature. A volcanic eruption can cause a cooling effect in climate because of the dust which flows on the rocks. Here the same thing happens as that of the asteroid impact. Ocean spreading are another sources for changes in climate. This happens when ocean's shape change therefore currents increases which can cause coolness or warmness in the climate, depending on the currents.
Other events which help in climate changes are the sunspot activities which happen every 11 years. These are spots on the sun that shines brightly which leads to cooling effect. Another event is the shifting in the angles at which the moon orbits the earth, which happens every 18 years (app.). this effects...