WASHINGTON (AP): The environmental footprint of data centres already rivals some of the world's largest countries, according to a United Nations University report, which also predicts their water and energy use and pollution will double in just four years as use of artificial intelligence grows.

Last year, global data centres used 448 trillion watt-hours of electricity, more than all but 10 countries of the world, said the report issued on Wednesday. That electricity use produced about 208 million tons (189 million metric tons) of carbon dioxide, about the same amount as Argentina, and producing that much energy consumed about 1.2 trillion gallons (4.5 trillion litres) of water, according to the report on the environmental consequences of AI's energy use.

By 2030, data centres will account for nearly 3 per cent of the world's projected electricity use, with 935 trillion watt-hours. If data centres were a country, the country would be projected to rank sixth-highest in power use in 2030. That would produce nearly 440 million tons (399 million metric tons) of carbon dioxide, the report said. The study focused on energy use and didn't examine the massive amount of water used to cool data centres.