You mentioned CO2 sequestering.

"Ah, yes. It works like this. The 'wind-sox' over there", he points behind the palm trees, "are the key to CO2 removal; they are made from a carbon-fibre mesh impregnated with a special semi-permeable membrane developed to let 90% of the air leak through, while keeping all the CO2 inside. The CO2 enriched airflow leaves the 'toe' of each sock and feeds the wave cells under the deck, where it is compressed in several stages. The CO2 is extracted by washing with seawater, and the resulting 'rich' seawater is returned to the ocean at a depth of about 4kms. Here it will join the underlying ocean currents and not re-emerge for some centuries. In moderate weather conditions (5 m/sec wind, 4m waves) we extract 800 tons of CO2 per hour from the atmosphere.”

Don’t you have periods of calm when production is stopped?

“Rarely; this location was chosen for that reason, among others. We do have extended periods of low swell which is predominately from the South-West” he swings his arm aloft, “and there is talk of installing a ‘Wave Focussing Device’ upweather of us. Basically the WFD is a floating obstacle, moored to the seabed, which diffracts the waves as they pass round it and focus them onto us, doubling the usable wave energy. Its all a matter of economics, of course.” He pauses.
“And then there is the snow!" His eyes twinkle.

Snow, in this climate?

"Well, it is actually marine snow, normally a feature of more Northern oceans. The nutrient-rich deep water stimulates the growth of phytoplankton which float away with the current. They are the base of the food-chain, and absorb huge quantities of CO2 to build their structures. They also exude a carbon-rich mucus, which causes them to become stuck together along with all kinds of marine detritus, and this drifts down to the depths as 'snow-flakes' at the rate of about 50 metres per day. It is part of the natural process for locking up CO2 in the ocean; all we do is catalyse it."

And does that bring in an income?

"Indeed! At $14 per CO2 ton bounty paid by the World Carbon Trading bank, that is a tidy income, although not all of it is 'allowed', because it has to be offset against the CO2 brought up with the deep water. Efforts are taken to minimise that effect, of course, the cold water is never brought closer than 20m to the surface, which keeps it well out of the 'outgassing' region. However, some mixing with surface waters is inevitable, especially during heavy seas, so it has to be accounted for.
Altogether, with net CO2 lock-up and cold water mining, the CWM brings in about $900 million per year, which goes," he adds hastily, "direct to the investors to pay for the capital outlay!"

So how do you make your living?

"Well, the first thing you have to understand is that we're largely self-sufficient. The phytoplankton feeds fish which we can harvest for our own use, and catches around the CWM are at least equal to the 'good old days' that my grandfather used to talk about… and of course, it's sustainable. What's more, an area of 150kms around the CWM is a fish sanctuary protected by international treaty, so we are truly the custodians of this eco-zone. I do hear of big fishing boats further down-current from here, but they know we have radar and a satellite uplink, so they keep well clear."
"Then there are the gases that I mentioned before, basically a by-product of the WM, and then there is maintenance of the CWM itself, that’s a paying job!" He smiles. "Yes, Polynesians are pretty good mechanics, you know."
Maintenance is low, he explains, basically because the whole CWM is made of concrete with very few moving parts; however it all has to be inspected regularly and kept in top order. "There are two families on the island," he says, pointing at the rig, which by now resembles a huge silo, "and two on the atoll who get their income from the company for looking after the mechanical components. This income buys things which aren't made locally, for example clothes, tools, electronics, computers."

I raise my eyebrows.

"We're not primitive here, you know, electricity is generated by the WM and freely available, within limits… and," he adds, "we don't have to pay any taxes because we are independent! Medical expenses and schooling are provided by the company."
He smiles with pride at the children playing in the shallow water.
"The kids don't notice," he says, "but it's quite a shock the first time you snorkel 'over the edge' and there's suddenly 4kms of water under you!"

What about big storms? I ask, suddenly remembering that we are floating!

"Well," confirms the Chief, "because of its size, the WM not only straddles any ocean wave, but also extracts the energy from the waves, leaving nothing to 'rock the boat'. 200 meters beneath the ocean is a submerged 'keel' which adds anti-heave inertia to the 'bow' edge where the wave impact is greatest. The deck, although flat-looking, actually slopes down from 25m above water level at the outer edge to -2m at the calm inner edge. 27 metres in 500 is actually less slope than there is on a 'flat' roof. On top of the concrete deck is up to 4 metres of sandy soil to give some natural contours… "the coconut trees don't know the difference," he says, "and the flowers are a result of the fresh water which is abundant thanks to our desalination plant. Of course, we still get rain and that's caught underground and maintains most of the vegetation."

But don't you get lonely?

"Don’t forget you're talking to a Polynesian… my family have lived on small islands as long as anyone can remember, and anyway there are fifty families on the CWM. There are apartments on the island, for those who prefer the 'urban' lifestyle, and traditional houses on the atoll. It's more than 6 kms around the atoll, and it's 500m wide. This habitat has the distinct advantage of being unaffected by storms or rising sea levels (unlike a lot of other places in the Pacific), so all of it usable. "

What is the effect of the CWM on sea levels?

"Well, again I'm only quoting the scientists, but they say that if you leave all of the heat in the ocean surface layers, you could expect a sea level rise due to expansion of 34 mm per century, whereas spreading it out results in only 22 mm per century… something to do with the co-efficient of expansion of cold water being less than hot water. But, much more importantly, because the weather is 'driven' basically by the surface water temperatures, the effect on climate and particularly melting ice-caps is minimised by pushing the heat deep down. I even hear that the 'real' islands downstream of us are managing to keep their coral alive, thanks to the cool current."
He scratches his head.
"We have a major effect on the monsoon, as well. The rains are very dependent on ocean surface temperatures. It took ten years to finalise the locations for the first 2 machines, before the Indian government was satisfied that it had the best combination. Even now, they still reshuffle the Indian Ocean machines from time to time."

How about other parts of the world?

“I hear that in the North Pacific, where they found the ‘cold spots’ were having an undesirable effect on the weather, they have several miners working the other way round; pumping the warm water down rather than bringing cold up. They have ten times the number of wind-sox and an extra gas enrichment process. That allows them to lock up three times the CO2 that we do (even allowing for the snow), but then they don’t produce the plankton or the fish.”
Then near Korea there are a couple of Cold Water Miners using engineered diatoms.. these are single-celled organisms bred to produce skeletons with the right size pores to lock up CO2 directly from the ocean water. They then sink to the bottom taking the gas with them, in a similar way to our ‘snow’, but on an industrial scale. Very effective, I understand, but they are still experimental and it will be some years of further observation before more can be licensed.”

The Chief seems to have plenty of time to chat.

"Yes," he says, "things here pretty much run themselves. My job is mostly keeping the grown-ups in line (the families themselves sort out their own teenage problems, and the like) coupled with company representation. The company likes to promote the 'green' side of its image, emphasising the environmental advantages of Cold Water Mining, combined with clean-fuel production and CO2 removal. A good bit of my time is taken up on PR, and I like to show reporters and environmental groups this clean and efficient domain." He waves his hand around.

Just then, the Chief's mobile phone rings. "Hello, Gus" then "OK, I'll be over".
He looks at the rig, by now lower again. "Seems as if we need to take a trip to the island.. it'll be down in about ten minutes."
We stroll to the quay, and he jumps into a small dingy; "one of the privileges of rank", he says, nodding at the outboard motor.
Off we skim across the lagoon, the chief points out the fact that the lagoon and the island are actually hexagonal in shape. Under the water, you can just make out the darker lines where the various pipes and tethers cross, and imagine that you can see an outline of the keel under the WM..

Five minutes later we are at a floating jetty alongside the rig. It has a couple of flights of stairs, and we climb to the top to find ourselves in something resembling a large bus shelter. Several other people are there, waiting for the 'down', which looks to be about 10m away and coming fast. You estimate that the rig is dropping by the height of the room every 35 seconds, but even now it is slowing as the 'down' approaches.

It stops with millimetre precision. "fluid logic computer" says the Chief, leading the way though a gate into a large walled area. The top of the rig is flagstones, with palm trees and bushes in neat beds all around. Just off centre is a block of flats or offices, with a number of satellite dishes on the top. At the far side is a heliport... "basically for use in emergencies and by the WCT bank inspectors" says the Chief.

The reason for our visit is a hurricane alert. As we enter the conference room/ cinema, the satellite weather chart is already on display and being studied.. As a visitor, you are ushered into the picture gallery, which shows photos of the CWM being built and diagrams of the internals of the huge machine… everything is simple, but on such a scale!

Within 5 minutes the Chief has made his decision. The hurricane may swing to the west, and could cross this area; everything will be battened down, just in case. This involves the whole community in a half day's work and starts immediately. The chief issues orders over his 'fone.
"I've arranged for the chopper to take you off, he says. We've got some urgent air-freight to come out, so it won't be a wasted journey."
He waves at the building around us "Basically admin, with four storeys of apartments… don't like to live in hutches, myself, but some folk seem to prefer it!"

Can't you move the CWM?

"Well, we could, but it would be rather an effort… the anchors require special handling and have to be set onto prepared foundations… would take about 9 months… not worth thinking about just for a hurricane. We probably won't even stop production; never have so far. The official procedure is to stop 10m above the 'down', but that's just to avoid the worst of the wind, rather than for any effect it might have on the rig itself."

The company's shareholders like the fact that the CWM can be moved to a new location, as logistics/ politics require. "It may become necessary to permanently relocate next century when global warming is more localised", says the Chief "we may need to go and tweak things up near Japan".

We move into the next room, where there are a dozen tables.
"Just time for a bite before you go"

After a good meal of locally caught fish, accompanied by some excellent (duty-free) wines, you say your farewells. It is 200 miles to the airport, and you are not sad to be going by chopper. The machine will get you back to 'civilisation' in about an hour, and although it produces a bit of CO2, it is good to realise that it is 'just a drop in the ocean' compared with what the CWM is removing. How long will it be before the long-promised 'green revolution' comes, and we will all be using renewable energy?

Roger  Clark
STEP 2000