By JAMES WOODFORD
Phil Watson says 9.50 am on January 12 will be a preview of the state’s sea level future.
Watson is the Team Leader of the Department of Environment and Climate Change’s Coastal Unit and for the first time has launched a program to document the flooding impacts of the highest tide visible during daylight hours.
“It will allow everybody to get a glimpse into the future when mean sea level will be higher than today,” Watson says.
King tides happen twice a year – at night in winter and during the day in summer.
The upcoming king tide is predicted to peak at just over 2 metres. Based on analysis of ocean water levels from Fort Denison dating back to 1914, Watson says that this tide level is only exceeded on average for around 9 hours every year.
But, says Watson, if sea level rise continues to increase at current measured rates due to climate change then scientists project sea level along the NSW coastline could be 90 centimetres higher than today, by the end of the century.
Under these conditions, Watson advises that a king tide which is rare today could be exceeded as much as 35% of the time.
While most coastal infrastructure has been built with king tides in mind they can be devastating when they co-incide with large waves and storm surges generated by high winds and low pressure weather systems.
In the winter of 1974 the combined affect of high tides and a big storm saw the largest erosion event recorded in NSW when the ocean water level was measured at 2.37 metres, the highest in the history of water level recording in NSW.
This year for the first time DECC is calling on the NSW public to assist photograph and document the impact of the king tide predicted for January 12.
“In Sydney, the peak tide is predicted to occur at Middle Head at 9:50 am,” says the Department.
“The king tide will provide an opportunity to see areas along the coast that are subject to flooding and at risk from erosion and storm damage. It is also an opportunity to raise awareness of the long-term challenges of sea level rise. In recent workshops around the state, the Department has presented forecasts of climate change impacts, including the potential for sea levels to rise by 40cm by 2050 and by 90cm by 2100.
“DECC is also interested in photos of submerged foreshore areas and other areas that are vulnerable to inundation.
“The photographic coverage will help create a statewide snapshot of vulnerable areas, many of which will not have been recorded before. This will help planning for future implications of sea level rise.”
Mr Watson says while this year the official survey will be restricted to NSW, there has been significant interest in establishing a national event from next year.
“People can have a look at a king tide in 2009 and then contemplate what it would be like with an extra 90 centimetres of sea level rise by the end of the century,” he says.
*anyone interested in participating in the survey http://www.environment.nsw.gov.au/ and look under “What’s New”.
I live on the extreme western edge of the GDR, just over 1,040 mts, and often find sea shells in the bush scrabble. Nothing exotic, just marine snails and small mollusce like pippits.
They don’t appear to be too ancient and often lie on the surface so are wind/rain eroded and utterly bleached but I do wonder what they indicate.
The BM rockscape is mostly sandstone, presumably erstwhile sea bed but also shot with hard igneous, soft limestone and, strangest of all (to my ignorance), layers of (apparently) pristine white clay, almost enirely free of grit or gravel. Surely such clay indicates alluvial sediment or at least millenia of heavy rain in past ages? There are some sandy red clay pockets (not layers like the white) and even patches of almost blueish clay, though this tends to be with the white layers.
An area excavated in the steep hillside for a house site looks like a cream & jam layered cake.
I’ve got bumper stickers that have a high tide mark through the middle and say “2050 SEA LEVEL – Global Warming Action Now!” for any ‘ecoterrorists’ that want to stick them on their coastal cars or at prominent sites 90cm above the King Tide mark. Msg me at onetree_environmental@hotmail.com and I’ll post them out.
Hey, guess what? It wasn’t as big as they’d predicted! Does that mean the future (which this massive king tide was supposed to show us) is actually OK? Or does the failure to correctly predict a king tide, or accurately forecast the weather a week away, not relate to the ability to make predictions for 50+ years hence?
By the way, why when this king tide (didn’t) happen at about 10am, was the ABC still reporting it as a big event at 7.30pm? Is it just to try to keep the hysteria going? And why, when in the king tide story we are told to reduce our carbon footprint, is the subsequent item telling us how terrible it is that fewer tourists are coming here? Surely that’s a good thing – does a reduction in air travel and consumption not equate to a reduction in carbon footprint?
Australia’s Climate Action groups from across Australia are heading to Canberra, encircling Parliament House on the first day of sitting. After Rudd’s pathetic announcement of 5% emission cuts for Oz, his failure to meet the bar at international negotiations, and $4 Billion pledged in hard cash to the coal industry, it is clear that Rudd is not serious about climate change. That’s why it’s time to take mass community action.
This year is our ONE CHANCE to affect international policy. Failing that, we are saying goodbye to the world as we know it.
So head down to our capital city, join us at Parliament House, and make your voice heard where it counts.
Be there, or be as lame as Kevin Rudd.
http://www.climatesummit.org.au/
Event Details:
What: Australia’s Climate Action Summit
Where: Parliament House, Canberra
When: 8am, February 3, 2009