Without a doubt, increases in ocean heat content (OHC) and temperature are robust indicators of global warming during the past several decades. In a recent study, scientists have found that parts of the Pacific Ocean are absorbing heat faster than they have over the past 10,000 years. The results were published in the journal ‘Science’, suggesting seawater is capturing far more energy than previously thought and for now sparing land-dwellers from some of the worst effects of climate change.
Scientists are using this study to explain a recent slowdown in the rise of global surface temperatures, saying that much of the heat trapped by greenhouse gas emissions is actually going to the oceans.
Researchers collected marine sediment off Indonesia to measure the mineral content in the shells of a plankton species to see how it changes its composition as the ocean waters warm. In the analysis, scientists reconstructed the temperature of the plankton’s habitat in the middle depths of the western Pacific going back 10,000 years. The results of the study proved the rate of ocean warming has indeed accelerated, by about one-third of a degree Fahrenheit in the last 60 years, causing sea life to suffer.
“The ocean heating has been much faster than anything we’ve seen in the long term,” said Yair Rosenthal, a professor of earth sciences at Rutgers University and lead author of the study.
The ocean's heat content, accounts for about 90% of the earth’s warming, making it a more reliable indicator of climate change than surface temperatures.
Further, the IPCC (Inter Governmental Panel on Climate Change) also states that most of the heat that humanity has put into the atmosphere since the 1970s from greenhouse gas emissions has likely been absorbed by the oceans.
However, the ocean heating could be both good and bad! As temperatures in the atmosphere go up and down pretty quickly, seawater can absorb a lot of heat, preventing the land from heating up. This is may be less beneficial in the long run, because even if carbon emissions are reduced, it could take years or even centuries for the ocean to respond and therefore a lag could be created, which would have consequences far into the future.
Scientinst like Trenberth and others have expressed reservations about the pace of warming reported in the study published in the ‘Science’. They believe the ocean warming could be unique to the Western Pacific and that the study fails to account for the cooling and warming of naturally occurring climate patterns like El Nino and the Pacific Decadal Oscillation.
Though it can’t be denied, research has proven, some ocean areas have already acidified to cause harm to ocean life, bringing changes in ocean circulation, abrupting shifts in precipitation patterns, causing bleaching and subsequent deaths of reef-building corals and changing migration patterns of whales and seabirds.
Photo by rtcc.