Considering that the oceans cover 71% of Earth, considering the man-driven, massive amounts of CO2 discharged into the atmosphere over the last 150 years, it’s surprising that the effects on the oceans haven’t been previously analyzed.
Researchers at the Scripps Institute of Oceanography and the Lawrence Livermore National Laboratory, Livermore, California, examined both the warming in the upper 70 m of the ocean and the increasing salinity of the water.
Scientists used a rigorous process of detection to determine if the oceanic changes in salinity and temperature were caused by natural events, such as volcanic eruptions or solar fluctuations. Simultaneously, they used attribution to determine if changes were the result of external forcing, such as human-induced changes from an increase in greenhouse gases or changes in land cover.
The oceanographers concluded that the observed changes in the ocean are consistent with anthropogenic (human) forcing of the climate and said, “These results add to the evidence that human forcing of the climate is already taking place, and already changing the climate in ways that will have a profound impact on people throughout the world in coming decades.”
Because ocean currents redistribute heat around the world, they have a profound influence on global climate. Human induced climate change causes increased polarization of the Earth’s water cycle, resulting in arid regions becoming drier and high rainfall regions becoming wetter.
The shifts in the water cycle and global weather patterns are a threat to human societies and their ecosystems because they affect food availability, stability, access and use.
Sources: SmartPlanet Daily, December 19, 2012 Geolog.com, December 7. 2012
Study published in Geophysics Research Letters, November 2, 2012