Ocean temperatures, like their atmospheric counterparts, are increasing. As heat enters the earth’s atmosphere from the sun, it is stored in various components of the earth’s system – the ocean, the land and the atmosphere. The ocean, which covers 70% of the planet, stores about 90% of the Earth’s heat. By moving this heat in large basin wide currents, the ocean moderates climate.
According to NOAA’s national climatic Data Center, “the global ocean surface temperature for July 2009 was the warmest on record, 1.06 degrees F (0.59 degree C) above the 20th century average of 61.5 degrees F (16.4 degrees C).” The absorption of much of the Earth’s heat has caused the ocean to undergo a sustained warming trend over the last 50 years.
Changes in ocean temperatures have global impacts. As ocean temperatures warm, species that prefer specific temperature ranges may relocate as has been observed in copepod assemblages in the North Atlantic.1. Some organisms, like corals, are sedentary and cannot relocate with changing temperatures. If the water becomes too warm, they can experience a bleaching event. Warmer water expands and causes more ice melt, both of which lead to sea level rise.2 Higher sea level and warmer ocean temperatures can alter ocean circulation and current flow, increase the frequency and intensity of storms, alter habitat and impact weather worldwide.3-7