Desalination as an Adaptation Measure to Climate Change

Figure 1: Process Used in Desalination Plants1

Perth is home to one of 3 opertating desalination plants in Australia. The Kwinana Desalination Plant in the industrial area of Kwinana is the largest desalination plant in the southern hemisphere. The plant supplies 130 megalitres of water a day and 45 gigalitres per year to over 1.7 million Perth and South West, WA residents.6 Desalination is the process of removing salt and other minerals from water through the process of evaporation, condensation from heat, vacuum distillation or reverse osmosis (shown in figure 1). Through this process, otherwise undrinkable water becomes available for human consumption and also becomes available for crop irrigation. The byproduct of desalination is brine, a concentrated salt solution. Brine is released back into the ocean, causing ocean temperature rise, and changes in alkalinity and salinity. Australia is a country highly dependent on rainfall and reservoirs for fresh water supplies and desalination is no less important. In Perth, the desalination plant delivers water to Integrated Water Supply System (IWSS), 17% of Perth’s fresh water demands come from this water. Although desalination seems like a positive option available to many countries that have water shortages, it has negative impacts on the environment that could be exacerbated with projected climate change. In relation to climate change, are desalination plants a reasonable adaptation measure to combat water shortages? Is it sustainable for present and future generations?

Desalination plants return brine water to the sea. Brine water is the byproduct from desalination that contains high levels of salt and other dissolved minerals. Sea levels are expected to rise from 1.7-3.2mm per year globally. 5 Western Australia focused; sea levels are expected to rise by 7.4mm per year. 5 Rainfall is expected to decline by up to 20%5 and average temperatures are expected to rise by 0.4 to 2.0 degrees Celsius by 2030.4 Due...