Last year, the oceans absorbed a record-breaking amount of heat — equivalent to 12 Hiroshima bombs exploding every second

Photograph of the horizon out at sea.

The ocean soaked up more heat last year than in any year since modern measurements began around 1960, according to a new analysis published in Advances in Atmospheric Science.

The world's oceans absorb more than 90% of excess heat trapped in Earth's atmosphere by greenhouse gas emissions. As heat in the atmosphere accumulates, heat stored in the ocean increases, too, making ocean heat a reliable indicator of long-term climate change.