Oceans could explain slower global warming

Phys.org reports that studies in the leading journal Science suggest that the reason global warming seems to have been slowing down is because the oceans are absorbing more heat than previously thought.

Climate scientists in the U.S. who have reconstructed temperatures in the Pacific Ocean over the last 10,000 years find that its middle depths have warmed 15 times faster in the last 60 years than in the previous 10,000. This jump in temperatures suggests that recent human activities generating greenhouse gases could be responsible. Scientists estimate the previous temperatures of the ocean by measuring the chemistry of ancient marine life, such as the levels of magnesium to calcium in the shells of organisms buried in sediments about 1,500-3,000 feet down.

The research paper in Nature was led by Yair Rosenthal, a climate scientist at Rutgers University. He says, “We may have underestimated the efficiency of the oceans as a storehouse for heat and energy…. It may buy us some time — how much time, I don’t really know. But it’s not going to stop climate change.”

The UN Intergovernmental Panel on Climate Change (IPCC) has found a slowdown recently in the rate of global warming, but attributes it to factors such as fluctuations caused by volcanic eruptions, changes in solar intensity, and the effect of ocean movements.

The phys.org report of October 31 explains: “The IPCC scientists agree that much of the heat that humans have put into the atmosphere since the 1970s through greenhouse gas emissions probably has been absorbed by the ocean. However, the findings in Science put this idea into a long-term context, and suggest that the oceans may be storing even more of the effects of human emissions than scientists have so far realized.”

To read the article in Phys.org, click here.