Look at them icebergs. Out there in the open ocean. Just sitting there. Made of freshwater.
Melting away. Melting away into nothing. Nobody doing anything with them. What a waste.
Look at Australia. Land of desert and thirsty kangaroos.
Starving for water. Crying out for it! Is there no possible solution??
Throughout the 1970s and 1980s, members of the Australian scientific community
seriously studied the possibility of harvesting Antarctic icebergs out on
the open sea and towing them back to Australia.
The technologies are more developed than you might think, but sadly the idea never became
a reality. In this fun little video we are going to look at when Australia thought about
adding a couple Antarctic icebergs to their water supply.
Australia is one of the driest inhabited countries in the world.
Rain there is sporadic and unevenly distributed across the vast continent.
50% of the country's water usage comes in an area where just 6% of its rain falls.
The country also suffers extremely long dry spells.
The most recent one is the Millennium drought, which started in 1996 and lasted until early 2010.
But they have been happening long before that.
The city of Perth is the country's largest on the west coast, fourth largest overall. With 2
million residents, it is one of the most isolated major cities in the world. They need water too.
Most of the city's water supply has traditionally come out of the ground or from dammed reservoirs.
Aquifer withdrawal levels have been at their sustainable limits for many years.
Many of its surface rivers have salinity concerns.
Perth does have two desalination plants, but that is no panacea.
These facilities have cost, energy and environmental concerns of their own.
As the metropolitan area continues to grow, those water supply concerns will grow too.
The situation has led to occasional shortages, water restrictions, and concerns about the future.
In 1973, regional projections showed that the city would run out of water by the 21st century.
Antarctica has 60% of Earth's freshwater and 93% of the world's icebergs by mass - a
near-complete monopoly. Many of those icebergs break off into the water and float around for a
while before melting away into nothing. All that freshwater, just melting away!
What a waste ... and thus was born a crazy idea.
The first formal plan for capturing and harvesting icebergs goes back to 1949.
Oceanographer John Isaacs came up with it in a class at the Scripps Institute of Oceanography.
He subsequently published it in a February 1956 issue of Science Digest.
California was struggling - as always - with a water shortage
at the time. His idea was to tow an iceberg to the Southern California coast
with a 3 million tonne tugboat. The icebergs were to be sourced from Antartica or Alaska.
The idea floated in and out of the public sphere a few times after that. In 1969, two American
scientists did some engineering calculations and declared that such a venture could hold water.
In 1977, a Saudi prince presented an idea to tow icebergs to the city of Mecca
as a way to supply water there. He sponsored a science conference in Iowa to discuss the idea,
and 100 scientists from all around the world came to talk about it.
Sadly, the conference's consensus was that the unfortunate berg would melt
away as it approached the equator. More of a guess, really. Because what we know about
them is just the tip of the … iceberg. Get it? Because 87% of an iceberg's mass is underwater.
Australia has the advantage of being much closer to Antarctica than Saudi Arabia.
And the country's brutal droughts have buoyed the idea more than a few times over the past century.
In 1965, with Australia's southwest in the midst of yet another brutal drought,
an American company approached the Australian Antarctic Division or AAD about bringing a berg
out to the Great Australian Bight - a large open bay on the country's southern coastline.
That specific proposal sank but the idea sailed on.
Rising populations in cities like Perth prompted the government to consider even
unconventional ways to shore up the area's water supply.
Perth's water situation in the early 1970s led to a committee being set up within the
Australian Academy of Science for studying the idea's feasibility. The committee faced
a lot of public skepticism, since of course the idea seemed pretty ridiculous from the get-go.
One Academy member defended the project to a member of federal parliament:
"Imaginative schemes of this sort always stimulate the most conservative opposition"
And they really gave it a serious look-through! A number of Australians attended the aforementioned
1977 Iowa conference on iceberg utilization. They came back feeling that it might be worth pursuing.
One estimate from the 1970s claimed that over a trillion cubic meters of icebergs
can be harvested without environmental damage. This volume is equivalent to 2,000
times the size of Sydney harbor and can provide water for up to 6 billion people.
With that being said, a few technical challenges stand in the way.
Right here, let us put this conversation on ice for a little while so that we can talk
about the engineering and logistics of bringing a berg from Antarctica
to ... anywhere, really. The challenges are indeed daunting.
Researchers have chipped the harvesting process down into three stages: Iceberg selection,
Iceberg capture/towing, and Iceberg processing.
Major technical challenges exist within each of these steps.
Icebergs have to be captured while they are floating in the open sea.
You can’t just dynamite them off the ice shelf because taking them while they are still on the
Antarctic continent might be construed as a violation of the Antarctic Treaty.
They come in many different shapes and sizes - for example tabular, pyramidal, and dry dock.
The type researchers have identified as being most ideal for harvesting are the first one - tabular.
Tabular icebergs are characterized by their vertical sides and flat tops.
This presumably makes them more stable and less prone to flipping over,
which is going to matter a lot during the towing stage.
These icebergs break off from an ice shelf into the sea. These ice shelves are fed by
ice from the Antarctic ice sheet, which advances forward at a rate of about 300 meters a year.
The ideal iceberg also has to be the right size. They can’t be too large. As of the late 1970s,
when this data was collected, 20% of icebergs surveyed then were over 1 kilometer long.
1 kilometer is far too big to handle.
You are looking for something smaller. But if you pick one that is too small, then it might end up
melting during its 6-12 month long journey north to Australia. So you have to strike a balance. As
it turns out, the ideal sized berg is roughly 400 meters by 600 meters large and 150 meters deep.
Such smaller bergs - "smaller" being a relative term since they still weigh 25 million to 2
billion tons - are more likely to come from ice shelves with faster moving ice sheets.
The Amery and Ross Ice Shelves were the most promising.
As I mentioned earlier,
you have to nab icebergs away from the shore due to Antarctic treaty concerns.
Spearing bergs out on the open seas like as if they were Moby Dick presents a lot of challenges.
Have you ever heard of the Titanic? Free-range bergs, unlike their chicken counterparts,
can be extremely hazardous to floating things that want to stay afloat.
Companies and organizations have investigated and tested ways to harness and secure an iceberg.
Not for freshwater harvesting, FYI, but to clear open waters for shipping and oil rigs.
The work has been described as "tricky, tough and treacherous".
Harnessing an iceberg requires relatively calm maritime conditions.
You want a low level of ice concentrations, because towing an iceberg in icy waters
requires a very powerful boat - a nuclear-powered icebreaker,
basically - and puts a lot of tension on the towline. Which you do not want.
There are a number of proposed ways to capture an iceberg. Early iceberg harvesting proposals
encircled the bergs with a net of steel cables below its center of mass.
You then shackle the net to towboats and carefully bring it back.
In order to prevent the iceberg from rolling and becoming unstable during the tow,
people will calculate and monitor the sag in the heavy towline - a concept called towing catenary.
Once the iceberg is in tow, the tugboats have to get back as soon as they can.
Dragging the berg through the water generates heat friction and erosion,
causing the iceberg to start breaking apart while it is being dragged home.
This melt means that the iceberg is going to change shape during the towing,
which causes issues. For instance, the bolts attaching the nets might fall
off - which means winches and other tightening devices might be needed.
Tests have also shown that most towed icebergs end up splitting into two
equal pieces, which then start rolling and becoming unstable.
These extra motions will stimulate the melting process and can also expose the tugboat to danger.
And of course, you also have to pray that the weather cooperates.
Ferocious Antarctic storms, fog, and long dark nights
make iceberg harvesting practical only during the warmer Antarctic summers.
The melting issue is serious enough that some companies have proposed
an alternative capture method: Using large polymer
water bags so to make sure the iceberg’s meltwater does not vanish into the ocean.
There are companies that make big water bags capable of traversing the seas.
One such company is Nordic Water Supply in Norway.
They were contracted by the Turkish Government in 1997 to bag 7 million cubic meters of water
and bring it from Anatolia to Cyprus. This was not an iceberg but definitely interesting.
Getting the iceberg into the bag is interesting. First, the material. The wrapper has to be strong
but also lightweight and flexible. And it has to maintain those properties over a massive volume.
Then there is the actual action of wrapping. My favorite proposal is where you attempt to slide
a tabular iceberg into an envelope shaped bag ... just like that first MacBook Air and its envelope.
For now, many of the existing waterbags are not all that big.
They cannot carry even a small iceberg. But if you can scale up the materials
and the engineering, then it helps make what comes next a lot easier.
This area of iceberg processing has the most amount of speculation and the least amount of
actual engineering work done. Because nobody has ever really tried it, I reckon. And it shows.
Structures need to be built to handle and retrieve the freshwater once the iceberg
arrives at its destination. The process of how that might be accomplished depends
on the way we decided to transport the iceberg to the area in the first place.
If we had earlier decided to bag the icebergs before bringing them home,
then you simply squeeze the water out of the bag like a toothpaste into a storage facility of
some sort. Maybe a reservoir or something. Then you pull the now-empty bags out of the ocean.
If you had decided to tow the iceberg over though, the problem gets a little more complicated.
You park the iceberg a few meters away from a dock and anchor it. Then, now what?
A few people have thought about sawing it into smaller pieces
which you can then drag into a melting pool. Then you wait for it to melt.
Others have recommended drilling holes and dynamiting it into pieces.
Or you build a big empty lagoon, put the iceberg there and wait for it to melt. However there are
environmental and regional climate considerations associated with putting a big freezing iceberg
so close to a residential area. What might happen remains uncertain.
For now, it probably makes more sense to bag the iceberg and then get the water that way
rather than trying to dynamite bits and pieces of an iceberg near a busy port. Seems risky.
Furthermore, there will additional challenges to integrating iceberg water into a city's
existing water infrastructure. I sort of waved it away just now,
but how are you exactly going to get that water to people’s homes? One Western Australia review
noted that it may require laying 15 kilometers of undersea pipeline, an expensive prospect.
Iceberg transportation technologies have seen more innovation than most people might expect.
Despite this, the technology has yet to advance far enough to harvest big bergs
specifically for their drinking water.
Preliminary calculations by an iceberg water harvesting group in South Africa
estimated that it would cost about $500 million USD across five years to get the technology
good enough to harvest 2 cubic kilometers of water each year. And tugging a heavy berg for
so long is estimated to cost something like $1.5 billion USD of diesel fuel for a single delivery.
Now you might get some other benefits from having this technology. But as it is,
iceberg harvesting is not economically competitive with the ways we get water today.
At those costs, the city would rather buy a desalination plant.
The Perth Seawater Desalination Plant cost about $300 million USD ($389 million AUD) to build
and now provides 17% of the city's water.
Or just digging a hole, pumping out the water, and worrying about aquifer health later.
The Australian iceberg harvesting committee in the 1970s eventually failed for those economic
reasons. Perth's water managers listened to a few proposals but had already decided that:
> The economics of the exercise are too unfavourable to contemplate such
a proposal this century, if ever, for Perth’s water supply
The conclusion remained the same even a decade later when academics approached them with new
and improved iceberg bagging technologies. No interest in purchasing iceberg water.
A few proposed water pipelines also failed for the same reason.
It simply made more sense to drill for the water under the ground - limited
as it was - than to try to rope icebergs or pipe water from thousands of kilometers away.
Ultimately the idea turned out to be a little far fetched. But the fact people seriously
contemplated it means that Australia’s water supply issues were and remain very serious.
I wouldn’t put a semiconductor fab in Perth anytime soon.
Water crises are a recurring theme in this new world. Global climate change
will affect billions of people, as rain clouds and weather shifts from one place to another.
Patterns remain unclear right now, but Australia looks to be one of those losers.
For many years, westerly winds from Antarctica brought winter rains to the Australian continent.
But over the past 70 years, those westerlies have been moving southwards.
It has led to reduced rainfall, droughts and fires in Australia and New Zealand.
Just something to think about, as we close the chapter on an interesting history of the past.
Alright that's it for tonight. Thanks for watching. If you enjoyed the video,
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