A change in the The average weather we would expect over a long period of time (seasons, years, decades). Climate varies from place-to-place across the Earth. Climate is determined by long-term (over at least... More which has an effect that then causes further climatic change. There can be both negative and positive feedbacks. A negative feedback acts in the opposite direction to the main trend, and a positive feedback works in the same direction as the main trend. So, in terms of The enhanced greenhouse effect due to human activity and the resulting widely accepted rising average temperature near the surface of the Earth since the late 19th century (and its projected... More, a negative feedback has a cooling effect, while a positive feedback increases warming. An example of a positive feedback that could happen is when warming causes Permafrost is frozen ground that remains at or below zero degrees Celsius (32 degrees Fahrenheit) for two or more years. It forms in regions where the mean annual temperature is... More to melt. This may lead to an increase in A colourless, odourless gas (chemical formula CH4). Some microbesproduce methane. It can also be found in underground deposits. Methane is the main component of natural gas, which is is an important... More* being released from Definitions of the Arctic vary according to environmental, geographical, political, cultural and scientific perspectives. Some scientists define the Arctic as areas having a high latitude, long winters, short, cool summers,... More soils. Since methane is a A gas found in the earth's atmosphere that traps heat radiated from the surface of the earth, and causes the earth's temperature to rise. The term comes from the fact... More*, the extra methane may cause further global warming, which may make permafrost melt faster.