http://www.bbc.com/future/story/20180918-the-outrageous-plan-to-haul-icebergs-to-africa
As South Africa faces ever more severe water shortages, some experts are seriously considering a proposal to harvest Antarctic icebergs and haul them to Cape Town. What are the chances it will succeed?
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Central to the plan are the natural currents that converge around Gough Island: the Circumpolar Current, which runs like a ring road of icebergs around the Antarctic, and the Benguela Current, which runs in an arc from Gough Island to the cape and up the west coast of Africa. Sloane describes the challenge as simply ?changing train tracks at an intersection?. The tugs would only need enough brute force to change tracks ? other than that, the currents would do the delivery job for them. Even the destination point near the Cape, where the iceberg would be pinned into place using oil rig anchors 40 km offshore, remains in a cold current, reducing the melt-rate. The water would be harvested using open cast mining techniques carving into the top of the iceberg, with shuttle tankers carrying the water to the shore.
[ South Africa's water shortage is so severe, some forecasts predict that Cape Town's taps will run dry in 2019 (Credit: Getty Images) ]
But the water needs a buyer. When I contact the Cape Town authorities, the response isn?t positive. Councillor Xanthea Limberg, who heads the mayoral committee member for water and waste services, tells me bluntly: ?This proposal has not been considered suitable for Cape Town? Such a project is both complex and risky with an anticipated very high-water cost.? According to costings done by the City, the melt water is likely to cost approximately R29 per 1000 litres (roughly $2 or ?1.50 per 1000 litres), excluding the cost of infrastructure required to get the melt water onshore, which ?is likely to be substantial?, compared to R5,20 per 1000 litres ($0.36/?0.27) from surface water schemes: ?The City of Cape Town is therefore rather focussing on increasing groundwater abstraction, desalination, and capacity to treat and reuse wastewater,? says Limberg.
Glacial progress
However, Sloane and his team are not deterred. While the city runs the water infrastructure, it?s the national government that owns it. Sloane confirms that the city?s costings are about right. Surface water schemes are indeed a lot cheaper. However, iceberg water would not compete with groundwater but with costly desalination (or ?desal?) ? which has received huge sums of investment from the city.. ?Desalination cost can be up above R50 ($3.35/?2.55) per 1000 litres?, says Sloane, ?and long-term ?desal? [including the cost to build new plants] starts above R250 ($16.75/?12.75)? basically there is nothing cheaper than water from a dam. We?re not trying to replace that. We?re just trying to supplement it.? Sloane believes an undersea pipe could directly feed pure meltwater into the reservoirs, topping them back up.
In a final pitch to make the plan palatable to politicians, Sloane is now offering the water risk-free. Investors, Swiss-based Water Vision plus ?two South African banks and one insurance company?, are offering to fund the tow in its entirety, meaning that if it melts, fractures, or strays off course, the state authorities wouldn?t have to pay a penny. The cost would be a delivery charge upon arrival. It could be the right offer ? and the right team, in the right location ? that finally makes iceberg towing a reality.
In September, Sloane, Orheim, Mougin and others were invited to make their pitch to the national government?s advisory body Water Research Commission (WRC). Sloane tells me afterwards that it went well. The WRC?s Dr Shafick Adams agreed that his group needed to be ?more adventurous in our thinking?, and was keen to do this, but still wanted more detail on ?the scientific, environmental and economic feasibility?. Sloane tells me the weather window for a 2018 tug has now closed, meaning it would be 2019 at the earliest.
But there is a final twist in the tale. There are companies and vessels in the world that already, regularly, tow icebergs. Off the coast of Newfoundland expensive oil platforms need to be protected from the regular flow of icebergs ? this is the sea where the Titanic was sunk. Organisations such as C-Core and Atlantic Towing are hired by oil companies for iceberg protection. And, in brief, they think the plans of Mougin and others are unrealistic, to say the least.
