Another “the science is settled” moment. From the ABC:
A new US-led study, featuring research by Tasmanian scientists, has concluded that warming ocean temperatures over the past 50 years are largely a man-made phenomenon.
Researchers from America, India, Japan and Australia say the study is the most comprehensive look at how the oceans have warmed.
The study, published today in the journal Nature Climate Change, examined a dozen different models used to project climate change, and compared them with observations of ocean warming over the past 50 years.
It found natural variations accounted for about 10 per cent of rising temperatures, but man-made greenhouse gases were the major cause.
One of the report’s co-authors, Hobart-based Dr John Church, is the CSIRO Fellow with the Centre for Australian Weather and Climate Research.
He told AM the study was one of the most comprehensive looks into the changes in ocean heat to date, “by quite some margin”.
Dr Church said the breadth of the study had “allowed the group to rule out that the changes are related to natural variability in the climate system”.
He said there was simply no way the upper layers of every ocean in the world could have warmed by more than 0.1 degrees Celsius through natural causes alone.
“Natural variability could only explain 10 per cent, or thereabouts, of the observed change,” he said.
Professor Nathan Bindoff is one of the world’s foremost oceanography experts, and has been a lead author on past Intergovernmental Panel on Climate Change assessment reports.
“Ninety per cent of the temperature change stored in the whole of the Earth’s system is stored in the ocean, so global warming is really an ocean warming problem,” he said.
Professor Bindoff said the new research balanced the man-made impacts of warming greenhouse gases and cooling pollution in the troposphere against natural changes in the ocean’s temperature and volcanic eruptions.
“This paper’s important because, for the first time, we can actually say that we’re virtually certain that the oceans have warmed, and that warming is caused not by natural processes, but by rising greenhouse gases primarily.”
And he described the evidence of global warming as unequivocal.
“We did it. No matter how you look at it, we did it. That’s it,” he said.
h/t to reader Mick Muller