Oceans Warming Faster Than Anticipated

Mindy Sparks
November 4, 2018

The new research, funded by the Princeton Environmental Institute and the National Oceanic and Atmospheric Administration, estimates that the world's oceans absorbed almost 13 zettajoules of heat each year between 1991 and 2016.

According to their most recent assessment this month, scientists from the Inter-governmental Panel on Climate Change (IPCC) say the world's oceans have absorbed 90% of the temperature rise caused by man-made carbon emissions.

"We thought that we got away with not a lot of warming in both the ocean and the atmosphere for the amount of [carbon dioxide] that we emitted", one of the report's authors, Princeton geoscientist Laure Resplandy. She said their data show it would have warmed by 6.5 degrees Celsius every decade since 1991.

The Sea of Japan, for example, has warmed around 3 degrees Fahrenheit in the past 100 years, as Reuters recently reported.

Resplandy and Keeling instead collected data by measuring the volume of gases, particularly oxygen and carbon dioxide, that have escaped the ocean as it heats up and entered the atmosphere over the past few decades.

"It's not that easy to reliably estimate the whole ocean heat from spot measurements", Ralph Keeling, climate scientist at Scripps Institution of Oceanography and co-author of the report, told the San Diego Union-Tribune. The IPCC is the leading global body for the assessment of climate change, and its evaluations form the backbone of the technical guidelines used by policymakers.

It's thought global warming of more than 2 degrees would produce a "hothouse earth", in which boiling temperatures could become a regular feature of the Earth's climate, and rising sea levels could wipe out swathes of land. (3.6?), it is all but certain that society will face widespread and risky consequences of climate change.

The new report found that emissions levels in coming decades would need to be 25 percent lower than laid out by the IPCC to keep warming under that 2 degree cap. Prior to that, the methods used to measure and calculate ocean heat had multiple flaws. Global temperature records were spotty before 2007, when an worldwide consortium began a program, known as Argo, creating an worldwide network of ocean-temperature-measuring instruments. Earlier estimates of the heating of the oceans have been drawn from hydrographic temperature measurements and data taken from the Argo float program. The extra heat absorbed by the ocean every year is more than eight times the world's annual energy consumption. But Resplandy and her team measured the amount of oxygen and carbon in the air, a number they call "Atmospheric Oxygen Potential (APO)".

"When the ocean warms, it loses some gas to the atmosphere", Resplandy said. APO also is influenced by burning fossil fuels and by an ocean process involving the uptake of excess fossil-fuel CO2.

The UN report used the old assumptions for heat absorbed in the ocean, Miller added.

Other reports by Iphone Fresh

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