Mixing the Ocean - Benign Geo-engineering

World ocean fisheries have greatly declined, while demand for wild fish has continued to increase.

Half of the world’s wild ocean fish depend on natural upwellings, which bring nutrients up into the sunlit surface, the “euphotic” zone, from deeper, more nutrified layers. These natural upwellings occupy only 0.1% of the surface of the ocean.

Adding an extra 0.2% of upwelling area to the oceans would double the world’s supply of wild fish.

Using Geothermal Energy to Mix the Ocean

This company was originally set up specifically to submit an entry to Sir Richard Branson's Virgin Earth Challenge. The Virgin Earth Challenge is a prize of $25m for whoever can demonstrate to the judges' satisfaction a commercially viable design which results in the removal of anthropogenic, atmospheric greenhouse gases so as to contribute materially to the stability of Earth’s climate. So far no-one has won the prize. The research we carried out to support our entry opened up whole new fields which are described elsewhere on this web site.

Not only can we remove CO2 but our method decreases ocean acidity and generates large amounts of fish. These new fisheries alone make the project commercially viable even without income from carbon credits.

The costs and benefits are described in detail here.

"Invention Could Reverse Decline of World Ocean Fisheries"

The Nutrient Megapump

We devised a large pump which uses the heat energy of a hydrothermal vent on the ocean floor to generate the potential energy needed to overcome the density stratification of the upper ocean. The pump has no moving parts and uses self-generated sonic shocks to act as valves in controlling the flow of fluid. The heat energy contained in 1 kg of vent fluid at 360 deg C is suffient to mix 30 tonnes of nutrient from 1000m depth into the sunlit surface layer of the ocean, i.e. the pump has a "gain" of 30,000 and the vent fluid is also diluted by this ratio.

The Nutrient Megapump is decribed here.

The Virgin Earth Challenge

We submitted our entry to the Virgin Earth Challenge in December 2009. It appears there were over 850 entries, none of which were deemed good enough to win the $25 million prize.

The important details of our entry where we demonstrate the commercial viability of our scheme are shown here

"It can never work" - the Luddites

Lovelock and Rapley proposed bringing nutrients, nitrate and phosphorus, found at depth, to the surface of the ocean in order to remove CO2 from the atmosphere by the ensuing photosynthesis ('Ocean pipes could help the Earth to cure itself', Nature, 449, 403; 2007). Their proposal was criticized by Shepherd et al ('Geo-engineering might cause, not cure,problems' Nature, 449,781;2007).This paper appeared in Nature remarkably soon after the appearance of the Lovelock and Rapley paper (2 weeks).

We immediately responded with a closely reasoned argument based on the physical chemistry of CO2 and observed concentrations and temperatures at 4 locations in the Pacific. We demonstrated that CO2 would indeed be sequestered at 3 out of the 4 chosen locations. This paper was rejected by the editors of Nature. The public has been left with the misconception that Lovelock and Rapley (and us) are wrong and that Shepherd et al are correct. Our paper never made it to peer review - its rejection was decided by the editors.

If any criticism can be levelled at Lovelock and Rapley it is that their proposed energy source(ocean surface waves) is unlikely to be sufficiently powerful to provide the required mixing.

Our unpublished Letter to Nature can be downloaded here (245 kB PDF)


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