The Rising Tide

Adelaide beachfront

The next time you go to an Adelaide beach, consider the following: All that water we see before us was not there 12,000 years ago, when sea levels were 50 metres below the present level. (http://sahultime.monash.edu.au/explore.html)

And 18,000 years ago, when it was even colder, the beach was the other side of Kangaroo island…

So what was the temperature when there was no sea in Gulf St Vincent – when it was a large valley that the Kaurna people hunted in?

Current data indicates it was approximately 4 degrees lower.

Clearly, small changes of temperature cause BIG changes in sea level. 18-20,000 years ago, when temperatures were about 8 degrees lower, the sea level was 120 metres lower!

So, what does this mean for us today, with temperatures and CO2 steadily rising? How high could sea levels go?

James Hansen, Director of the Goddard Institute of Space Studies, claims that CO2 was between 350-500 ppm (parts per million) when Antarctica froze over, and that this glaciation is reversible. We are currently at 387 ppm of CO2, and it is rising at about 2ppm each year.

That puts us on track, with business as usual, to reach 500 ppm – the maximum CO2 concentration at which the Antarctic froze - in 56 years. (We are already well past the minimum estimate - 350 ppm).

If we reach the conditions in which the Antarctic froze 34 million years ago, it stands to reason that, if these conditions then persist, the entire continent will thaw.

The general scientific consensus is that the melting of both Greenland and the Antarctic would raise sea levels by 70-75 metres. (Note the Eocene point – when the world was last ice-free.)

This would not be immediate, and would happen over decades and centuries – but it is highly likely that, once begun, the melt would be unstoppable, due to positive feedback mechanisms.

And the likelihood is that, given current trends, we will reach this point (500 ppm) within the lifetime of a young person today.

What would this mean for Adelaide? A 75m rise would mean that the sea level would, eventually, come up to here:

… and here…

The Uniting Church at Norwood (cnr Parade and Portrush Rds) would be on the shoreline.

…as would Urrbrae High School.

Doom, gloom! Is it preventable? You bet! The world possesses the technology to go carbon-free, economically, within the few decades we have left before this point is reached.

(Solar thermal centre)

Check out this visionary scheme, as just one example - Australia exporting solar electricity to Asia: forget dirty old coal! http://www.desertec-australia.org/index.html

...and this tidal energy scheme, that could provide 35% of Australia’s energy needs: CETO … and this, which could provide another 20%: worleyparsons

The only thing stopping us are large vested interests, and a lack of political will. To overcome this, we need a vibrant, broad, and popular movement to campaign for renewables now!

As part of building this process, the Climate Emergency Action Network (CLEAN) invite you to a Public Forum with interstate speakers this Friday night, 10th October, and an all-day conference on Saturday 11th October. Catch up on the latest science, and the latest ideas on how to organize and resolve the climate crisis.

The Friday Oct 10th Public forum will be at the Basil Hetzel Auditorium at UniSA, Frome Road, City, 6pm to 8.15 pm. Organised by CLEAN, with support from the AEU. Entry by donation.

On Saturday 11th there will be all-day plenary sessions and workshops addressing the following themes: • This is an Emergency - An Introduction to the Real Science of Global Warming • Why not business as usual? • Ways Forward - Offering Directions • Let’s get active! What can we do Locally, Nationally, Globally? • Beyond Business as Usual.

Saturday Oct 11th Sessions (admission free) held at: Australian Education Union Building 163 Greenhill Road, Parkside. 9 am- 5.30 pm. Organised by the Australian Education Union, with support from CLEAN. For registration go to http://www.aeusa.asn.au/formregistration/5335.html For further information and full program go to www.climateemergency.org.au or www.aeusa.asn.au/events/5297.html or ring 0400754559

Come along and do your bit to hold back the rising tide!

Please pass on to all your contacts to help build the climate emergency movement…