World view
Phytoplankton absorbs more than one million tons of carbon dioxide each day from the atmosphere. Ocean stores carbon dioxide 50 times more than atmosphere stores and 20 times more than the organism stores. Thus, ocean is responsible for the buffering role of climate change.
Sea surface temperature is the most important physical characteristics of the world's oceans. Sea surface temperature varies mainly depending on latitude. In general, the warmest water is in the equatorial region and the coldest water is in the North Pole and the South Pole. As ocean absorbs more heat, sea surface temperature will rise and change ocean circulation patterns transferring the heat around the world.
Global warming caused by human activities that emit greenhouse gas (heat-trapping carbon dioxide) has raised the average global temperature by about 1°F (0.6°C) over the past century. In the oceans, this change has only been about 0.18°F (0.1°C). This warming has occurred from the surface to a depth of about 2,300 feet (700 meters), where most marine life thrives.
Sea surface temperatures have been higher during the past three decades than at any other time since reliable observations began in 1880. Increases in sea surface temperature have largely occurred two key periods: between 1901 and 1940, and from about 1970 to the present. 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.
