This time weâre talking about rising ocean temperatures.
This has commonly been applied to trends in atmospheric temperatures (as shown in the 2007 IPCC report), where itâs clear that the observed warming wouldnât have happened without rising greenhouse gases.
Increasingly reliable records of ocean temperatures have now allowed some of these same researchers to confidently apply the technique to Earthâs seas. This is important because some 90 percent of all the energy trapped by human greenhouse emissions has ended up in the ocean, not the atmosphere. The trend with ocean heat content is clearâitâs rising. The question is whether that rise could be caused by natural variations.
Researchers averaged the results from a number of climate models, and compared that to global temperature records for the upper 700 meters of the ocean from 1960 to 1999. The temperature record is less complete for the deep ocean, and its massive volume and separation from the surface subdues its response to climatic changes. In addition to the global average, they also analyzed each of the major ocean basins (North and South Atlantic, North and South Pacific, North and South Indian) separately.
They found that the anthropogenic âfingerprintâ was apparent in the observed temperature record at the 99 percent confidence level. That means the observed warming is beyond the variability seen in model simulations where greenhouse gases are kept constant, but is exactly what the models predict for a world in which humans change the composition of the atmosphere.
http://arstechnica.com/science/2012/06/yet-another-study-confirms-global-warming-is-human-caused/
This has commonly been applied to trends in atmospheric temperatures (as shown in the 2007 IPCC report), where itâs clear that the observed warming wouldnât have happened without rising greenhouse gases.
Increasingly reliable records of ocean temperatures have now allowed some of these same researchers to confidently apply the technique to Earthâs seas. This is important because some 90 percent of all the energy trapped by human greenhouse emissions has ended up in the ocean, not the atmosphere. The trend with ocean heat content is clearâitâs rising. The question is whether that rise could be caused by natural variations.
Researchers averaged the results from a number of climate models, and compared that to global temperature records for the upper 700 meters of the ocean from 1960 to 1999. The temperature record is less complete for the deep ocean, and its massive volume and separation from the surface subdues its response to climatic changes. In addition to the global average, they also analyzed each of the major ocean basins (North and South Atlantic, North and South Pacific, North and South Indian) separately.
They found that the anthropogenic âfingerprintâ was apparent in the observed temperature record at the 99 percent confidence level. That means the observed warming is beyond the variability seen in model simulations where greenhouse gases are kept constant, but is exactly what the models predict for a world in which humans change the composition of the atmosphere.
http://arstechnica.com/science/2012/06/yet-another-study-confirms-global-warming-is-human-caused/
