Sorry to crush George W.’s and Star Trek’s fans’ illusions, but I believe that colonizing oceans could offer more interesting possibilities than outerspace. Mars… well that’s another story…
OK, so, let’s start daydreaming!
First, a look at the scenery.
Close to 70% of the Earth is covered by water.
Most of that volume is left unexploited, with exception of fisheries, which unfortunately deplete stocks, mostly because there is no efficient plan to manage fish stocks in a sustainable manner.
The timid colonization efforts are limited to fairly coastal activities.

Natural resources
While on the land, it has become more and more difficult to extract metals and minerals, there is a vast hardly explored potential for these natural resources lying at the bottom of the sea. Many open-sky mines have been exploited to almost full potential. Drilling and mining at deeper and deeper levels have resulted in higher and higher costs. All things considered, it is probably cheaper to drill through a layer of (soft) water than hard rock, and there are areas known where metals are available on the surface of the oceans bottom.

Energy
Tremendous energy potential is available in and over the oceans.We have huge reserves of hydrogen in there. Of course, to produce it we will have to produce the necessary energy to split the water molecules. Using fossil fuel cannot be an option, as the gas emissions would defeat the purpose.
The great thing is that the energy needed can be found in the oceans themselves. Why not think of having large wind or solar farms located on oceans (probably not too far offshore), dedicated to splitting water and producing hydrogen and oxygen. The hydrogen could be used in fuel cells, and the oxygen could be used to allow the people involved in underwater activities and settlements to breathe.
Further, more electricity can be produce by using the strong currents to run through turbines.
It could be also interesting to consider the possibility to create floating solar energy farms.
It such a scenario, it is not unthinkable that all our energy needs for cars, factories and industries could come from clean emission-free electricity.

Water
Water, and especially clean drinking water will be one of the biggest challenges that mankind is going to face in the future.
Of course, there is plenty of water in the oceans, but the main problem will be to make it drinkable.
Considering that in the fantasy I am writing here, I envision human settlements on (or in?) the oceans, there will have to be drinking water available.
Next to desalinization, the other most obvious source of drinking water is collecting rain.

Capturing carbon
There are projects of using minerals to change the pH of the sea with the hope that this would help absorb CO2 much faster than it naturally currently happens. Although, this might be our last resort if we do not get our emission under control. The problem is that we have about no idea on what the side effects on the ecosystems might be, and that is a scary thought.
Here, I want to focus on more positive ways to use ecological methods.
On the land, we are losing more and more trees as a result of our need for more and more land, and therefore we are losing the natural capacity to capture CO2.
Then why not think of replacing these lost trees by cultivating the oceans and develop large vegetal populations, in other words, grow aquatic meadows and forests?
This must be done with care of course as the ocean life is a three dimensional thing with depth playing a significant role, while on land it looks more like two dimensional (limited depth/height significance).
Another area of attention when developing such vegetal populations is to make sure they do not get out of control and impact the oceans ecology as many other species with interact with them, creating complete ecological systems and food chains.

Developing a whole new aquaculture
Here, I use this term in its literary meaning, which is cultivating the water, not just restricting it to the production of a few commercial aquatic species, as it is the case today.We should be able to cultivate the water en develop it in a similar way as we did with agriculture, but also by learning from the mistakes we have made in agriculture.The only way that the current aquaculture farms can survive is to produce (cultivate) the foodstuffs it needs in the oceans as well. Keeping on doing as today has probably not that much future, as the need for fish meal, and mostly fish oil will exceed by far the current production possibilities, and exhausting the wild stocks used for that clearly could not work. Further, replacing these foodstuffs by vegetal protein and fat from agricultural crops will not work, either, because there will be too much competition from the needs for land-based animal productions and the needs for human food. Clearly, the only way to meet the increasing needs for seafood is to grow the foodstuff in the sea.
This opens a tremendous project of picking which foodstuffs to produce in the sea, how to manage them, how to combine the mix of production and ensuring the sustainability of this new aquaculture, and at the same time ensuring that the marine ecosystems recover and function properly as well.
This will require an aquaculture of plankton, of algae, of aquatic plants, of fish, of shellfish, of mammals en maybe more.
So far we have depleted the food chains in the sea, now is the time to restore them, next to increasing our ocean-based food supplies.

The challenges
Well, you will say: that sounds all very nice but is it realistic?
And I would answer, maybe it is not quite realistic today, but if we work on it, quite a few things named above can be achieved. Actually, some have already started.
The main challenge I see is to cope with the tremendous forces that oceans can unleash, such as currents, storms, waves and pressure in the depths; and we would need to build in a way that can deal with such forces, if we want to avoid disasters.
But you have to agree that there is lots of space available on our planet this way and it here right here “at home”.

Copyright 2009 The Happy Future Group Consulting Ltd.