Every year since 1977, the average annual global sea surface temperature has been above the 20th century average. The chart shows the temperature difference compared to the 20th century average each year in degrees Celsius.
Bar chart showing temperatures above and below the 1981-2010 average. It shows temperatures rising almost every year over the past century.
An increase of 0.5 degrees Celsius is equivalent to 0.9 degrees Fahrenheit.