The Earth is undergoing a major rapid warming, unprecedented in its speed for millions of years. How is this affecting the physics of the oceans, and thereby us? The lecture will cover ocean warming and its consequences:

- Arctic summer sea ice cover has shrunk by half in extent and also in thickness, so that only about a quarter of the ice mass that was normal until the 1970s is left now.

- Thermal expansion and loss of land ice is causing global sea-level to rise, by around 20 cm thus far, and accelerating. The latest IPCC report concluded that 2 meters by the year 2100 cannot be ruled out.

- Tropical cyclones draw their energy from the heat stored in the upper ocean and are consequently already getting more violent with global warming, and also extending their range to higher latitudes.

- The Atlantic meridional overturning circulation (AMOC) has been weakening since the mid-twentieth Century and is now weaker than any time in the last 1,000 years. This is of great concern as it is already having an impact on European weather, and the AMOC has a tipping point where it will grind to a halt altogether.