Oceans heating faster than previously thought

A man walks past a boat anchored at the Indian Ocean in Mombasa 2011. /FILE

A man walks past a boat anchored at the Indian Ocean in Mombasa 2011. /FILE

Most atmosphere researchers have concurred in the previous decade that if worldwide normal temperatures surpass pre-industrial levels by 2℃ (3.6℉), it is everything except sure that society will confront far-reaching and hazardous outcomes of environmental change.

Because of the oceans' rise in temperature, more gas is being lost from the ocean into the atmosphere.

Oceans not only purify the air but also absorb heat; and in the last 200 years, they have been performing that function with the gases that we humans have been emitting.

Up until the report was issued this week, the Intergovernmental Panel on Climate Change (IPCC) thought it had a pretty good handle on how much excess energy the oceans were absorbing.

"The ocean warmed more than we thought, and that has serious implications for future policy", Resplandy said. They measured ocean heat by looking at the combined amount of O2 and Carbon dioxide in the air. It says that rainfall, warm spells, and the number of "tropical nights" - when temperatures stay above 20 degrees Celsius - are all on the rise. For example, the Sea of Japan has warmed around 1.7 degrees Celsius over the past 100 years. The authors of the new study weren't satisfied with the ocean temperature and salinity information that people have always used, which is gathered from a system of almost 4,000 ocean buoys in waters around the world, called Argo.

"Imagine if the ocean was only 30 feet (10 metres) deep", said Laure Resplandy, assistant professor of geosciences at Princeton and lead study author.

As well as potentially making it more hard to keep warming below 1.5 or even 2C this century, all that extra heat going into the oceans will prompt some significant changes in the waters. If those warming impacts are underestimated, humanity could easily skid past its goals for capping climate change. The hotter it is, the more oxygen and carbon dioxide the ocean pushes out. Instead the researchers have used an alternative measure based on atmospheric oxygen and carbon dioxide. This allows them to accurately measure ocean temperatures globally, dating back to 1991, when accurate data from a global network of stations became available.

"When the ocean warms, it loses some gas to the atmosphere", Resplandy said.

"So what we measured was the amount lost by the oceans, and then we can calculate how much warming we need to explain that change in gases".

"The ocean circulation that controls the ocean heat uptake/release operates on time scales of centuries, meaning that ocean heat would be released for the centuries to come". It also helps reduce uncertainty in the 'climate sensitivity, ' and reduces the possibility of very low climate sensitivity, according to Keeling.

The UN report used the old assumptions for heat absorbed in the ocean, Miller added. The IPCC is the leading worldwide body for the assessment of climate change, and its evaluations form the backbone of the technical guidelines used by policymakers.

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