Europe's largest desalination plant for drinking water had largely remained idle since its construction near Barcelona over a decade ago. But since a prolonged drought gripped Spain last year the plant has been running at full throttle to help keep some five million people adapt to climate change and not go thirsty. Before the drought desalination provided just 3% of Barcelona's drinking water. Now desalination is its leading source of water, providing 33% of the city’s water compared to 19% that currently comes from its shrinking rivers. But desalination comes with high costs both for taxpayers and for the environment due to its high energy costs which can actually make the underlying conditions of climate change worse.