How can we talk about climate change over the next 100 years when we can’t be sure of tomorrow’s weather?
Weather and climate are different. The methods used to forecast changes in weather and climate differ as well. Climate can be thought of as average weather, including weather’s variability over long time periods. Natural changes in climate happen over the course of decades, centuries and many millennia. Global Circulation Models (GCM) are able to account for the many factors that influence climate over long periods, such as changes in the sun’s energy and the level of greenhouse gases (GHG) in the atmosphere. These models tell us what the average weather is likely to be but are not able to identify specific weather events.
