ABSTRACT

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 Sources of Climate and Weather Data for the GBR and Queensland . . . . . . . . . . 270 Average Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272

Surface Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 Sea Surface Temperature, Atmospheric Circulation, Cloud, and Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 Tropical Cyclones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Rainfall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 River Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275

Example of Influence of Mean Climate Conditions on Coral Growth Rates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275

Inter-Annual Variability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 El Niño-Southern Oscillation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 Impact of ENSO Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 Coral Bleaching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 Impact of Anti-ENSO Events. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 Freshwater Plumes and Luminescent Bands . . . . . . . . . . . . . . . . . . . . . . . . . 277

Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 Changing SSTs and Air Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 Changing Rainfall and River Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Records from Corals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279

Future Climate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 Projected Climates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282

Weather, the instantaneous state of the atmosphere, is how we experience the atmosphere around us at a given moment and place (temperature, wind speed, rain, etc.). Climate is what we expect the weather to be at a particular time and place based on

many years of weather observations. Climate includes both average conditions and variability about that average (i.e., range of extremes). Climate varies naturally from year to year but usually within the range of average climate. A climate change occurs when there is a significant change in average climate and/or its variability so that our expectation of weather changes. In this chapter average surface climate conditions in the vicinity of the Great Barrier Reef (GBR) are presented (Figure 1). The effects of the major source of inter-annual variability on surface climate of the GBR, the El Niño-Southern Oscillation (ENSO), are documented. Evidence for climate variation and change over the past century (based on instrumental observations) and past several centuries (from proxy climate records derived from corals) is examined together with an assessment of possible changes in GBR climate due to the enhanced greenhouse effect.