Modelling Climate Change
Climate models attempt to simulate the behaviour of the climate, in an attempt to understand the key physical, chemical and biological processes which govern climate. Climate models give us a better understanding of the climate system, providing us with a clearer picture of past climates by comparison with records of instrumental and palaeoclimatic observations, and enabling us to predict future climate change. Models can be used to simulate climate on a variety of geographical scales and over different periods of time. The basic laws and other relationships necessary to model the climate are expressed as a series of mathematical equations. The climate however, is a very complex system, and supercomputers are needed for the task.
Global climate models have been used extensively to project global warming in the 21st century due to mankind's greenhouse gas pollution of the atmosphere. Estimates of future increases in greenhouse gases are inputted into the model, which then calculates how the global climate might evolve or respond in the future to the enhanced greenhouse effect.
Although climate models can aid understanding in the processes which govern the climate, the confidence placed in such models should always be questioned. Critically, it should be remembered that all climate models represent a simplification of the climate system, a system that may ultimately prove to be too complex to model accurately. Climate models must therefore be used with care and their results interpreted with due caution. Margins of uncertainty should be attached to any model projection. Results from climate models should always be validated or tested against real-world data, including both instrumental and palaeoclimatic records where available.