Earth in hot water as sea surface temperature record broken

This article appeared as part of the Daily Sensemaker newsletter – one story a day to make sense of the world. To receive it in your inbox, featuring content exclusive to the newsletter, sign up for free here.

European scientists have said that temperatures on the ocean surface reached a record high of 21C on 21 June. This is bad news on multiple fronts. Marine fish suffer because warmer waters make their enzymes less efficient and contain less oxygen. Humans suffer because warmer waters lead to more evaporation, which causes overall temperatures to rise and also intensifies tropical storms. Climate change is to blame – oceans absorb more than 90% of the excess heat on Earth – but the onset of El Niño, a natural phenomenon, means the surface record is likely to be broken again in the coming months. Over the past three years, the global ocean outside the polar regions has been between 0.35C and 0.73C warmer than average.