700,000 Australian buildings at risk from Sea Level Rise

General news0

Friday, March 16, 2007

700,000 Australian buildings at risk from Sea Level Rise

An Insurance industry study in Australia has identified 700,000 buildings at risk nationwide from rising sea levels caused by human induced climate change. The study was done in 2006.

Karl Sullivan from the Insurance Council of Australia said “We’re working closely with government to try to map and understand what those risks are as climate change starts, or what the exact details of climate change may be and how it may manifest.” according to the ABC 7.30 Report.

According to 7.30 Report journalist Matt Peacock the Insurance report specifies that Sea Level Rise associated with King tides and storm surges may effect more than 700,000 buildings on the Australian coast. “In the Northern Territory nearly 900 coastal buildings, mainly in Darwin, are at risk. Along the Tasmanian coastline, more than 17,000 addresses are considered vulnerable. More than 60,000 in South Australia, mostly around Adelaide, and along the Victorian coast over 80,000, mainly around Melbourne. In Western Australia, 94,000 buildings have been identified around Perth, but the biggest concern is along the eastern seaboard; more than 200,000 buildings are considered vulnerable on the NSW coast, including Sydney. Queensland faces the largest risk, with almost 250,000 buildings under threat, stretching from the Gold Coast to the Sunshine Coast.”

Barrie Pittock, former head of the CSIRO and a contributor to the IPCC report, said on the 7.30 Report: “We have an increase in the outflow of glaciers from Greenland and parts of Antarctica already that have been observed. The latest papers suggest a rise by 2100 between about 50 centimetres and 1.5 metres, which is quite a lot more than the IPCC report.”

Barrie Pittock said that there is a crude rule of thumb effect of sea level rise which applies theoretically just to straight sandy beach, which suggests for every metre rise in sea level the coastline will retreat or go inland by 100m.

In Hobart this week (March 12-15) a conference of about 200 scientists met to discuss oceanography, including Sea Level Rise and ongoing monitoring of the earth’s oceans. Much of the accurate measurment data is collected from the Jason 1 satellite. Satellite measurements suggest that global warming is doubling the number of intense storms and coastal flooding on the West and East Australian coasts, and the rate of sea level rise is being severely underestimated by the IPCC recent report.

David Griffin from the CSIRO said that available data indicates that sea levels are rising faster than expected, and the main reason is climate change. His comments indicate a more accurate model is required to explain the rapid rate in sea level rise. “Well that underpins the importance to understand why the observed rate of sea-level rise is greater than the models can explain,” he said. “We’re relying on those models to make projections for the next 100 years. If they can’t actually explain the last 10 years, then we know that we’ve got more work to do.”

The head of NASA Oceanography, Eric Lindstrom, attending the conference, was reported by the ABC as saying that a lot of scientists are wondering when society will wake up to the seriousness of climate change. “I’d say the major force involved in these changes is human-induced climate change, global warming,” he said. “I consider this data very serious and that there is climate change happening and that we need to be concerned about it.”


So how bad could sea level rise be? The rule of thumb, according to Barrie Pittock is that for every 1 metre rise in sea level, the coast moves about 100 metres. If the Greenland and West Antarctic Ice sheets disintegrate rapidly, then sea levels may change at the rate of up to 1 metre per 20 years.

Outspoken NASA climate scientist, Jim Hansen, was interviewed by Kerry Obrien on the ABC TV current affairs program, The 7.30 Report. He gives a very graphic and detailed view of what we are facing with climate change and sea level rise. Interview Reproduced in full.

Australian Broadcasting Corporation
LOCATION: http://www.abc.net.au/7.30/content/2007/s1870955.htm
Broadcast: 13/03/2007
Scientist predicts disastrous sea level rise

Reporter: Kerry O’Brien

KERRY O’BRIEN: Welcome to the program and first, as the world continues to absorb the import of the recent UN intergovernmental report on climate change, with its projections for increased temperatures, violent storms and rising sea levels, one of America’s pioneering climate change scientists has raised a much more frightening scenario. Dr James Hansen, a prominent and controversial NASA scientist, has written a paper predicting catastrophic sea level rises from the disintegration of polar ice sheets if the globe heats up by two to three degrees Celsius this century. The IPCC report, written by hundreds of the world’s top scientists, has predicted temperature rises of from two to six degrees Celsius if greenhouse emissions aren’t reduced. Dr Hansen, who had a much publicised run-in with the Bush White House after accusing the administration of trying to gag him, has told this program that he expected both west Antarctica and parts of Greenland to collapse if temperatures reached 2 or more per cent, which could cause sea levels to rise at a rate of a metre every 20 years. Last night’s program showed how up to 700,000 homes around the Australian coastline have been identified as being at risk from much lower sea level rises. The Hansen scenario would potentially displace hundreds of millions of people around the world. I spoke with Dr Hansen from London earlier today.

KERRY O’BRIEN: Jim Hansen, now we’ve had the IPCC report, do you believe the world has an accurate picture of the risks ahead for global warming?

DR JAMES HANSEN, NASA CLIMATOLOGIST: There is quite a large gap between what is understood about global warming by the relevant scientific community and what is known by the public. The one thing that I’ve become particularly concerned about is sea level rise, where the current IPCC report is going to suggest smaller numbers than the last report, although all of the information that we’re getting in the last year or two points in a very much different direction. Now, in defence of IPCC, their procedure required that they stop getting new inputs more than a year ago and a lot of the data on ice sheet stability has come up in just the last year or two.

KERRY O’BRIEN: What are your particular fears with regard to the melting of the polar ice caps?

JAMES HANSEN: Well, the problem is that the climate system in general has a lot of inertia and that means that it takes time for the changes to begin to occur but then, once they do get under way, it becomes very difficult to stop them and that is true in spades for the ice sheets. If we once begin to disintegrate it will become very difficult, if not impossible, to stop them and we are beginning to see now on both Greenland and west Antarctica disintegration of those ice sheets. They’re both losing ice at a rate of about 150 cubic kilometres per year and that’s still not a huge sea level rise. Sea level rise is now going up about 3.5 centimetres per decade. So that’s more than double what it was 50 years ago. But it’s still not disastrous; it’s a problem, but it’s not disastrous. But the potential is for a much larger sea level rise. If we get warming of two or three degrees Celsius, then I would expect that both West Antarctica and parts of Greenland would end up in the ocean, and the last time we had an ice sheet disintegrate, sea level went up at a rate of 5 metres in a century, or one metre every 20 years. That is a real disaster, and that’s what we have to avoid.

KERRY O’BRIEN: What is the most recent evidence of what’s really going on with the ice caps, the Arctic and the Antarctic?

JAMES HANSEN: There are two things that are cause of concern. First of all, if we look at the history of the Earth, we know that at the warmest interglacial periods, which were probably less than 1 degree Celsius warmer than today, it was still basically the same planet. Sea level was perhaps a few metres higher. But if we go back to the time when the Earth was two or three degrees Celsius warmer, that’s about three million years ago, sea level was about 25 metres higher, so that tells us we had better keep additional warming less than about one degree. And the other piece of evidence is not from the history of the Earth but from looking at the ice sheets themselves, and what we see is that the disintegration of ice sheets is a wet process and it can proceed quite rapidly. We see that the ice streams have doubled in their speed on Greenland in the last few years and even more concern is west Antarctica because it’s now losing mass at about the same rate as Greenland, and west Antarctica, the ice sheet is sitting on rock that is below sea level. So it is potentially much more in danger of collapsing and so we have both the evidence on the ice sheets and from the history of the Earth and it tells us that we’re pretty close to a tipping point, so we’ve got to be very concerned about the ice sheets.

KERRY O’BRIEN: How good are the models on which world science is basing its climate change predictions?

JAMES HANSEN: Temperature we can, we now have that calibrated quite well, both in terms of how fast the Earth is now warming, which is about two-tenths of a degree Celsius per decade, and the climate models reproduce that, and the climate models can also reproduce the magnitude of the climate change from glacial to interglacial periods. So we’re pretty confident of climate sensitivity, and what that sensitivity tells us is that if we want to keep warming less than one degree Celsius additional above that of today, we had better keep CO2 less than 450 parts per million, and perhaps even less than that. So we’re really getting close to the tipping point, because CO2 is now 380 parts per million. It started out, 100 years ago, at 280, it’s now 380 and it’s going up 2 PPM per year. So if we stay on as business as usual, within about 30 years we will be past this level that, I think, is a very dangerous level.

KERRY O’BRIEN: You said a year ago that in your 30 years working in government you’d never seen such constraints on communication between scientists and the public. What’s the evidence of that?

JAMES HANSEN: Well, it worries me a lot because in our country the government science agencies have public affairs offices which are now staffed with political appointees and those political appointees have a big impact on what science gets reported and how it’s reported. And I’m very disturbed about that. I think that public affairs officials should be helping scientists speak in a language that the public can understand but they shouldn’t be massaging the information. And the other example is reporting, testifying to Congress. I don’t understand why a scientist’s testimony has to be approved by the White House. Government scientists are paid by the public, paid by taxes and I think we’re working for the public and for Congress, as well as for the executive branch, and I don’t think that our testimony should be filtered.

KERRY O’BRIEN: You said just a couple of weeks ago that there should be a moratorium on building coal fired power plants until the technology to capture and sequester carbon dioxide emissions is available. But you must know that that’s politically unacceptable in many countries China, America, Australia for that matter, because of coal industry jobs and impact on the economy.

JAMES HANSEN: Well, it’s going to be realised within the next 10 years or so that we have no choice. We’re going to have to bulldoze the old style coal fired power plants. We can burn coal, provided we capture the CO2 and sequester it, and we’re working on technology that would allow us to do that and we should have been working a little harder but, nevertheless, we will have, within five to 10 years, we will have that technology. In the meantime, we should be emphasising energy efficiency so that we don’t need new old style coal fired power plants. We’re just not doing that. Buildings could be 50 per cent more efficient. The architects and engineers will tell you they have the technology to do that, but if it’s not required it’s not likely to happen.

KERRY O’BRIEN: After your 20 years as a scientist of trying to raise awareness of the dangers of global warming, are you ultimately optimistic or pessimistic about the future?

JAMES HANSEN: I think that we’re likely to pass the 450 parts per million, which is probably the dangerous level. However, I think there is a lot of encouraging evidence in the last year or two that people are starting to get it, and so – if we can keep it close to that level, and take some additional actions. You know, there are other climate forces besides carbon dioxide, and some of those – it would be very useful to reduce those. And so if we begin to address carbon dioxide and methane and black carbon and tropospheric ozone then I think we can avoid the dangerous climate change but we’ll have to get going very soon.

KERRY O’BRIEN: Jim Hansen, thanks for talking with us.

JAMES HANSEN: Thank you.


West Australian 6 March, 2007 – Scientists to discuss global sea rise

ABC News 12 March, 2007 – The CSIRO says sea levels are rising faster than expected

ABC News 12 March, 2007 – NASA official ‘surprised’ climate change still debated

The 7.30 Report – ABC TV – 12 March 2007 – Coastal areas face environmental threats

PM – ABC Radio – 13 March 2007 – Global warming doubling number of intense storms

The 7.30 Report – ABC TV – 13 March 2007 – Scientist predicts disastrous sea level rise

NASA – The Earth Observatory = June 2006 – The Rising Sea Level

Leave a Comment

You must be logged in to post a comment.

This site uses Akismet to reduce spam. Learn how your comment data is processed.