Warmer oceans are creating bigger and more destructive storms, as we saw with Harvey and Irma. Sea surface temperatures have been consistently higher over the last 30 years than at any time since measurements began in the 1880s.

Here & Now's Jeremy Hobson asks Andrew Sweetman, associate professor at the Lyell Centre for Earth and Marine Science and Technology at Heriot-Watt University, how warmer surface temperatures are affecting the ocean floor and the deepest parts of the ocean.