Climate change can be defined as distinct changes in measures of climate lasting for a long period of time. It is therefore not ‘weather’ which a day-to-day phenomenon. Climate can vary on long timescales due to a variety of reasons including due to natural variations and also due to human induced activity. It is the change due to human activity which is most often being referenced when climate change is discussed. The human induced change results from increased concentrations of greenhouse gases (e.g. carbon dioxide and water vapour) in the atmosphere as a result of human activities such as the burning of fossil fuels and deforestation.