This graph shows how the average surface temperature of the world’s oceans has changed since 1880. This graph uses the 1971 to 2000 average as a baseline for depicting change. Choosing a different baseline period would not change the shape of the data over time. The shaded band shows the range of uncertainty in the data, based on the number of measurements collected and the precision of the methods used.
Data source: NOAA, 2014 5
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Web update: May 2014
This map shows how average sea surface temperatures around the world changed between 1901 and 2012. It is based on a combination of direct measurements and satellite measurements. A black “+” symbol in the middle of a square on the map means the trend shown is statistically significant. White areas did not have enough data to calculate reliable long-term trends.
Source: IPCC, 2013 6
Key Points
- Sea surface temperature increased over the 20th century and continues to rise. From 1901 through 2013, temperatures rose at an average rate of 0.13°F per decade (see Figure 1).
- Sea surface temperatures have been higher during the past three decades than at any other time since reliable observations began in 1880 (see Figure 1).
- Increases in sea surface temperature have largely occurred over two key periods: between 1910 and 1940, and from about 1970 to the present. Sea surface temperatures appear to have cooled between 1880 and 1910 (see Figure 1).
- Changes in sea surface temperature vary regionally. While most parts of the world’s oceans have seen temperatures rise, a few areas have actually experienced cooling—for example, parts of the North Atlantic (see Figure 2).
US EPA
http://www.epa.gov/climatechange/science/indicators/oceans/sea-surface-temp.html