Desalination is particularly important in arid and semiarid climates, coastal cities and small island states . There were 16,000 operational desalination plants globally in 2017, with a daily desalinated water production of 95 million m3 d-1 . In 2012, desalinated water was equivalent to 0.6% of the global water supply, and 75.2 TWh of energy per year was used to generate desalinated water; in other words, about 0.4% of the worldwide electricity consumption . Unfortunately, only 1% of total desalinated water uses renewable sources  . Desalination has already helped to meet urban and peri-urban water supply, particularly during annual or seasonal drought events, with half of the world's desalination capacity in the Arab region . In addition, seawater desalination could help address water scarcity in 146  large cities  megacities) . Desalination is also being adopted for irrigation. For example, in the island of Gran Canary , 30% of the agricultural surface area is irrigated with desalinated water to irrigate high-value crops . The expected growth of desalination, if not coupled with renewable energy , causes a projected 180% increase in carbon emissions by 2040 . There have been advances in large-scale and on-farm renewable desalination . Using renewable energy to decarbonise desalination has meant that the projected global average levelled cost of water could decrease from €2.4 m-3  to approximately €1.05 m-3 by 2050, considering unsubsidised fossil fuel costs . Desalination will be maladaptive if fossil fuel is used .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report