Greenhouse gases largely to blame for warming oceans: scientists

Updated June 11, 2012 11:28:50

Photo: The study says greenhouse gases are largely to blame for ocean warming (David Loh: Reuters)

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.

Topics:climate-change, earth-sciences, science-and-technology, oceans-and-reefs, environment, tas, united-states, australia

More evidence of severe weather most likely due to Global Warming.

Note the severe weather our East Coast is currently getting, after the driest May on record. This is not a natural weather pattern we are now seeing. Damage on the East Coastline is yet to be assessed.

More cyclone-like storms to hit WA

Updated: 18:39, Monday June 11, 2012

Wild weather forecast for vast tracts of Western Australia on Tuesday is likely to wreak as much havoc as Sunday’s storms, emergency services predict.

A large part of the state’s south is expected to be hit late on Tuesday by winds of about 125km/h, equivalent to a category two cyclone, Bureau of Meteorology spokesman Grahame Reader says.

The area spans from Geraldton in the Mid West region to Southern Cross in the Wheatbelt to Israelite Bay in the Goldfields-Esperance region.

Mr Reader says the initial impact would be in the southwest corner of the state, moving up to Perth during the evening, then peaking at around midnight WST.

The wild weather would begin to ease on Wednesday morning, he says.

It was rare – a once in 10 years event – for Perth to be hit by three major storms in just a few days, he said.

The fourth strongest wind gust on record hit the city on Sunday, clocking 146km/h.

It came three days after a tornado swept through the northern suburbs of Dianella and Morley, damaging homes and businesses, uprooting trees and hurling shopping trolleys through the air.

Sunday’s storm brought down 120 power lines, ripped the roof off a block of units, tore boats free from moorings and even lifted a circus tent from the ground.

Emergency Services Minister Troy Buswell said the storm was unprecedented both in terms of severity and the size of the affected area.

Mr Buswell said at least 10 hospitals lost power during the storm and were forced to use generators.

Several schools had to suspend classes on Monday because of damaged roofs and lack of power.

Mr Buswell said 52 traffic lights were not operating but major intersections were either being manned by police or powered by generators.

‘This week shapes to be a difficult week for our state and particular for the southwest in terms of dealing with storms,’ Mr Buswell told reporters.

‘Preliminary advice is that storm event (on Tuesday) will be as significant as yesterday’s event and may well extend further to the east.’

While electricity utility Western Power earlier on Monday said it could take up to a week to restore power to 100,000 homes, Mr Buswell said he was reluctant to predict how long it would take.

‘It is difficult to give an exact end point because at the moment, we can’t predict the impact of tomorrow night’s storm event on the electricity network,’ he said.

Power had been restored to more than 50,000 homes since Sunday’s storm struck.

Western Power was focusing on removing dangers – particularly fallen live power lines – before restoring energy supply.

Mr Buswell said damage from Tuesday’s storms could be exacerbated by remaining debris that emergency services workers were currently battling to clear.

The State Emergency Service had received more than 700 requests for assistance, Fire and Emergency Services Authority of WA spokesman Brad Stringer said.

Mr Buswell said it remained to be seen whether Tuesday’s weather would lead to a natural disaster being declared.

Signed,