South East SA Climate Ready Climate projections for South Australia This document provides a summary of rainfall The region and temperature (maximum and minimum) information for the South East (SE) Natural Resources The SE NRM region (from the Management (NRM) region generated using the northern Coorong and Tatiara districts latest group of international global climate models. to the coast in the south and west, Information in this document is based on a more and Victoria to the east) has wet, cool detailed regional projections report available winters and dry, mild-hot summers; at www.goyderinstitute.org. with increasing rainfall from north to south; coastal zones are dominated by Climate projections at a glance winter rainfall, whilst more summer rain is experienced in inland areas. The future climate of the SE NRM region will be drier and hotter, though the amount of global action on decreasing greenhouse The SA Climate Ready project gas emissions will influence the speed and severity of change. The Goyder Institute is a partnership between the South Decreases in rainfall are projected for all seasons, Australian Government through the Department of Environment, with the greatest decreases in spring. Water and Natural Resources, CSIRO, Flinders University, Average temperatures (maximum and minimum) are University of Adelaide, and the University of South Australia. projected to increase for all seasons. Slightly larger increases In 2011, the Goyder Institute commenced SA Climate Ready, in maximum temperature occur for the spring season. a project to develop climate projections for South Australia. The resulting information provides a common platform on which Government, business and the community can By the end of the 21st century develop solutions to climate change adaptation challenges. Average annual rainfall could The project has produced the most comprehensive set of decline by 6.5-15.9% detailed, local scale climate projections data ever available in South Australia. It covers rainfall, temperature, solar radiation, vapour pressure deficit and evapotranspiration. Average annual maximum temperatures could increase by 1.6-3.2°C Average annual minimum temperatures could increase by 1.4-2.7°C . How was the data generated? The climate projection information presented here is based on 25543 selected future climate change scenarios, projected to occur under two emissions scenarios defined by the Intergovernmental Panel on 25527 Climate Change (IPCC). The climate projection information presented 25523 here is based on selected future climate change scenarios which the 25546 25526 25541 IPCC describe as “representative concentration pathways” (RCPs). 26049 25507 The high emissions scenario referred to in this document is RCP8.5 25525 25518 and the intermediate emission scenario is RCP4.5. 26065 The IPCC’s emissions scenarios are the product of an innovative 26017 collaboration between integrated assessment modellers, climate 26037 26010 modellers, ecosystem modellers as well as social scientists working 26058 on emissions, economics, policy, vulnerability and impacts. 26069 26078 Detailed, local scale data were generated for the region 26062 using 15 Global Climate Models (GCM) and applying a technique called “downscaling” at selected weather stations. 26026 26075 While using 15 GCMs provides a broader range of possible future climate changes, this document uses data from a subset of the 6 “best” GCMs. These models were chosen because they were 26014 found to perform better at representing climate drivers that are 26021 particularly influential on rainfall in South Australia, such as the 26027 El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole. Further information on methods, data and outputs is available 26067 in the full regional report available at www.goyderinstitute.org. Figure 1. Location and identification numbers of the 24 weather stations in the SE NRM region Emissions scenarios The two emissions scenarios used 1000 throughout this document are the 900 Intermediate emissions scenario (RCP4.5) intermediate “stabilisation” 800 High emissions scenario (RCP8.5) scenario called RCP4.5 and the 700 “high emissions” scenario RCP8.5. 600 Currently, global emissions of concentration (ppmv) (ppmv) concentration 2 500 greenhouse gases are tracking at CO 400 or above the RCP8.5 trajectory. 300 2000 2020 2040 2060 2080 2100 Year How to interpret the graphs in this document The red line indicates the The blue line indicates the The line indicates high emissions scenario intermediate emissions the average while (RCP8.5) which arises from scenario (RCP4.5) the shaded area little effort to reduce emissions which would stabilise indicates the range. and represents a failure to the carbon dioxide curb warming by 2100. concentration by 2100. Rainfall Climate modelling suggests that average Seasonally, there is variation in both the average and range of declines projected. The largest change by 2070 annual rainfall could decline by up to occurs in spring under both emissions scenarios, with 6.5-15.9% by the end of the 21st century a 21.8% and 33.9% decline under the intermediate and in the SE NRM region. high emissions scenarios, respectively (Figure 2b). Furthermore, by 2070, under intermediate emissions summer, Average annual rainfall is projected to decline under autumn and winter may at times experience wetter years than both intermediate emissions (RCP4.5) and high the baseline average (Figure 2b). Under high emissions, however, emissions (RCP8.5) scenarios (Figure 2a). only autumn and winter may have wetter years (Figure 2b). By 2030 projected rainfall reductions are similar under both Both emissions scenarios are consistently drier in spring. emissions scenarios. However, by the end of the century, projections diverge, with average rainfall declines more than twice as much under high emissions (Figure 2a). There is considerable overlap in the range of projections across the coming century. Projected percent change in average annual and seasonal rainfall Figure 2a Projected percent change in average annual rainfall. -3.5% -5.4% -4.4% -7.4% -6.5% -6.6% -11.9% -15.9% to the baseline period (1986-2005) to Mean projected change (%) compared compared (%) change Mean projected Figure 2b 2070 Projected percent change in average seasonal rainfall. -0.3% -5.8% -5.5% -0.7% -14.0% -9.2% -21.8% -33.9% to the baseline period (1986-2005) to Mean projected change (%) compared compared (%) change Mean projected High emissions scenario (RCP8.5) Intermediate emissions scenario (RCP4.5) Shaded area indicates the range Maximum temperature Climate modelling suggests that average While the difference between emission scenarios is small early in the century, by the end of the century maximum temperature annual maximum temperatures could under high emissions is double that under intermediate emissions. increase by up to 1.6-3.2°C by the end of Seasonally, the pattern of change in average maximum st the 21 century in the SE NRM region. temperatures is similar between emissions scenarios by Under intermediate emissions (RCP4.5) average maximum 2070. Across all seasons, temperatures are greater under temperatures could increase by 0.8°C by 2030 and 1.6°C high emissions by 0.9-1.1°C by 2070 (Figure 3b). by 2090 (Figure 3a). Changes are even greater under Warming in the spring is projected to be greater than any high emissions (RCP8.5), which projects an increase of other season under intermediate and high emissions (Figure 1.0°C by 2030 and 3.2°C by the end of the century. 3b). The projected ranges about the averages indicate higher variation under high emissions compared to intermediate emissions, particularly in the summer (Figure 3b). Projected change in average annual and seasonal maximum temperatures Figure 3a Projected change in average annual maximum temperature. 3.2ᵒC 2.4ᵒC 1.6ᵒC 1.6ᵒC 1.0ᵒC 1.4ᵒC 1.1ᵒC 0.8ᵒC to the baseline period (1986-2005) to Mean projected change (°C) compared compared (°C) change Mean projected Figure 3b 2070 Projected change in average seasonal maximum temperatures. 2.4ᵒC 2.7ᵒC 2.3ᵒC 2.1ᵒC 1.4ᵒC 1.6ᵒC 1.4ᵒC 1.2ᵒC to the baseline period (1986-2005) the baseline period (1986-2005) to Mean projected change (°C) compared compared (°C) change Mean projected High emissions scenario (RCP8.5) Intermediate emissions scenario (RCP4.5) Shaded area indicates the range Minimum temperature Climate modelling suggests that average The spring warming experienced in the maximum temperature projections are not repeated in the minimum temperature annual minimum temperatures could projections. By 2070, for example, autumn minimum temperature increase by up to 1.4-2.7°C by the end of the increases are projected to be 0.2-0.5°C greater than other seasons 21st century in the SE NRM region. under high emissions, and under intermediate emissions, are the same as summer but greater than spring and winter (Figure Under the intermediate emissions scenario (RCP4.5), 4b). Changes in minimum temperatures are projected to be average minimum temperatures will rise by 0.6°C by lowest in winter under both emissions scenarios (Figure 4b). 2030 and up to 1.4°C by 2090. Under the high emissions scenario (RCP8.5) a rise of 0.8°C is projected by 2030 Like the maximum temperature change projections, the and 2.7°C by the end of the century (Figure 4a). value ranges show low overlap between emissions scenarios, with the difference increasing over the years (Figure 4a). Minimum temperature increases are consistently greater under high emissions. By the end of the century, the projected changes under high emissions are nearly double those under intermediate emissions. Projected change in average annual and seasonal minimum temperature Figure 4a Projected change in average annual minimum temperature. 2.7ᵒC 2.0ᵒC 1.4ᵒC 1.4ᵒC 0.8ᵒC 0.9ᵒC 1.2ᵒC to the baseline period (1986-2005) to 0.6ᵒC Mean projected change (°C) compared compared (°C) change Mean projected Figure 4b 2070 Projected change in average seasonal minimum temperatures.