A short history of the future: Australian climate projections 1987–2015

Abstract

This paper describes the history of national climate change projections for Australia since 1987, with a focus on the series of statements in 1992, 1996, 2001, 2007 and 2015. These were prepared by CSIRO up to 2001, and by CSIRO and the Bureau of Meteorology from 2007 onward. A range of scientific and communication issues were addressed in preparing each statement, including decisions concerning climate model ensembles, emission scenarios, forming ranges of change, use of probability, use of expert judgment, spatial resolution, presentation methods and representing uncertainties.There are a number of perennial issues, trends and tensions, which may be of interest to future production of regional projections for Australia and other regions. For example, managing and communicating uncertainty in future climate due to differing emissions and model responses has been a perennial element of the projections. There has been a trend towards wider scope in variables analysed, time periods discussed and use of peer review, as well as greater content in the statements over time, partly reflecting available modelling results and the increasing range, needs and sophistication of users. There are several notable tensions in this work, reflected in some approaches being adopted and then dropped in subsequent statements. Examples include the choice of spatial resolution, the use of probability, model evaluation and expert judgement. These tensions reflect the difficulty in striking the right balance between competing scientific considerations or between scientific credibility and saliency for users.