Number Theory: Sea surface mercury set for record highs
This is the last of a two-part data journalism series which explains why 2024 is the warmest year for the planet.
The first part of this series explained how it is almost certain that the average global temperature will be the warmest ever this year. However, what is normally known as temperature is air temperature two metres above the earth’s surface. Another set of temperature numbers which deserve close attention are sea surface temperatures (SSTs). Although strongly correlated with air temperatures, SSTs do not always move exactly the way air temperatures do. For example, air temperatures in 2015 would only be ranked seventh warmest (after 2024 data is factored in) in the data produced by the National Oceanic and Atmospheric Administration (NOAA), a United States government agency; but SSTs would be ranked fourth warmest. This is not the case in 2024, where SSTs are also likely to break previous records. Here is how.

