New Mars Forums

Yes, we may get by.  But the global resource estimates are not calculated on the basis of price.  The estimates do in fact include previously uneconomic oil.  The fact remains that no matter how advanced our discovery and mining technologies, there is less and less oil to be had with each passing year.  Eventually, production will start to decline.  New discoveries of oil may delay or cushion that decline, but nothing can change the fact that the total amount of oil is finite and the more that is produced, the less that is left to be produced in the future.

Our problem is this: Oil exists in different grades.  The best oil was the light sweet crude from super-giant, land based reserves, mostly in the US.  This was the cheapest to extract in terms of money, energy and manpower and also the easiest and cheapest to refine.  The cheapest oil was exploited first, simply because it was easier to get at and cheaper to produce.  As the demand for oil increased progressively, producing nations were forced to develop more difficult reserves, including smaller land-based wells, then deep water production, then natural gas liquids, polar oil and finally tarsands.  The incremental cost of each new barrel of oil increases progressively, not just in money terms but also in terms in the infrastructure, man-power and energy required.

As conventional supergiant fields are increasingly depleted, new production must make up not only incraesing demand but also the declining output from the cheaper supergiants.  The marginal cost of each new barrel of oil increases progressively, until eventually, it becomes impossible for new production to make up for depletion in mature regions.  At this point, total production begins to decline.  This is commonly known as peak oil and it is not a theoretical occurance.  It happened in the US in 1971, the UK in 1999, Norway in 2000.  Of the sixty or so lareg produceing nations, approximately two-thirds are either at peak or beyond it.  Global production is simply the sum of all production from all regions.  So a global peak within the next 10 years is virtually inevitable

This will happen on a global level within the next ten years, possibly before 2010.

False.  This is issue is generally poorly understood, even within the scientific community.

Global oil discovery peaked in the 1960s and global crude oil production peaked in 2005.  Most of the increases in recent years have come from condensates and natural gas liquids, which are generally located in deep water or are associated with natural gas production.  They are more expensive to produce than conventional crude.  Total liquids peak may occur as soon as 2010.

Undeveloped reserves are available in the Arctic, off the coast of Brazil, west Siberia, West Africa and Antarctic.  But these reserves are far more expensive and difficult to exploit than 'conventional' crude, and are often located in politically difficult areas.  New developmnets must meet not only expanding demand, but must replace depleted production from existing oil fields.  With each passing year it becomes more and more difficult to achieve that.  Eventually, probably very soon, we will witness a peak in total liquids production.  This represents the point at which the effects of depletion within existing wells overwhelms our ability to bring new production on stream.  At this point, plenty of oil will be left in the ground and the world will still be producing a great deal.  But production will decline continuously with each passing year.

Hydrogen is the least promissing of all alternative fuels.  It suffers from a critical efficiency problem that makes it unsuitable as an energy carrier.

The technology that is most promissing for road vehicles in terms of overall energy efficiency and technical practicality is electric, probabaly a combination of battery and flywheel electric power and conductive transfer, via an electrified conduit embedded within the roadway.  In the near term, electricity production is likely to come from coal (increasingly in highly efficient combined cycle gassification plants) declining amounts of natural gas and oil (burned in combined cycle plants), stable contributions from hydropower, small increases in other renewables such as wind, wave and solar and stable or slowly increasing contributions from nuclear.

I am very confident that hydrogen powered vehicles will never be a mainstream technology.

US ethanol production will die a quick death because of its very poor EROI (energy return on investment) which is about 1.3 at best.  Fast growing algae are a more likely energy crop, given that they can be grown in saline water on otherwise useless land and have a much higher conversion efficiency for sunlight into carbohydrate than any landbased plant.  These makes them very fast growing.  there may be small contributions from crop wastes, but these will be limited in the future by the need to use composted wastes as soil stabilisers.

All biofuels are much more efficiently used in highly efficient electricity plants, rather than as liquid fuels for car engines.

Rising oil prices are the result of rising demand from the developing world and geological depletion of existing fields.  The world can no longer expand supply rapidly enough to meet new demand.

Whilst there are alternative ways of producing gasolene (coal/gas to liquids, biofuels, etc) they are (a) limited in supply by the massive capital cost of new projects and the sheer scale of the developmnet process required to bring them online in meaningful quantities (b) far more expensive than conventional crude derived products.  It is highly unlikely that synthetic fuel production will expand rapidly enough to offset a peak in global oil production before 2015. 

When oil production peaks, it could easily be the worst thing that has happened to the developed world since the second world war, similar to or more severe than the depression of the 1930s and probably longer lasting, given that the cause will be geological energy depletion.

People generally seem to be completely unaware and unprepared for the scale of the disaster that we are about to walk into.  Natural gas is also set to peak in the next decade or two and coal production is unlikley to expand rapidly enough to offset both peaks.

Interesting idea.  The obvious difficulty of using a mass driver in the Earth's atmosphere is the heat and pressure wave generated, as the projectile plows through the air.  How far up would we need to go before this effect would be tollerably easy to design around?

One problem with attempting to tether a balloon in the upper atmosphere is the mass of the cable needed to hold it is place.  If we can build a carbon fibre 50 kilometres long, why not go the whole hog and build one 36,000km long?

You believe that building a space elevator is achievable in the near term.  I have strong doubts that (1) Materials science is capable of yielding a sufficiently strong carbon fibre nanotube that is 36,000km long and that (2) The capital costs will be affordable in the near term.

I am not a luddite and I try not to be over-conservative.

Building a space elevator will not provide a cheap access to space for the majority of human beings and there are serious persistant reasons to question whether they are possible at all.  The capital costs put the cost of every other human project in the shade and are likely to require a significant fraction of the sustained income of all of humanity to achieve.  Then there are the practical concerns of extending diamond fillament or nanotube finbre thousands of kilometres into space.  This is not a project that we will see accomplished in our lifetimes or grandchildrens lifetimes.  My impression is that many people on this list have a poor basic feel for the scale of the challenges involved in space projects and make unrealistic assumptions on what we are likley to see in our lifetimes.

Scramjets of the other hand are a relatively near-term technology and BDBs are effectively present day technology.  In terms of being cheap, it is doubtful that any technology will get you into space for anything less than your entire life savings, not now or in 100 years time.  But BDBs take a technology that is at least proven and developed and reduce the cost to reasonable limits by simplifying the technology and making it suitable for common ship-yard grade manufacturing, ie, simple steel construction, pressure-fed ablative engines that are simple and easy to make, liquid (non-cryogenic) fuels that are easy to plumb and work with, etc.

Scramjets approach the problem from a slightly different angle and their higher capital and development costs are presumably offset by extensive reusability.  For a BDB, it is often assumed that the lower (booster) stage will be reusable and the upper stage expendable.  There are significant technological problems with the idea of producing a reusable vehicle capable of reaching orbital velecities.  This relates both to the complexity of a vehicle capable of achieving sufficient mass ratios and the extensive maintenance that is required between launches.

I believe that hydrogen reactes exothermically with CO2.  This would appear to be a good airbreathing fuel on Mars, especially for aircraft which do not need to store LH2 for long periods.

Silane is another good fuel that will burn in CO2 and is generally a lot more storable than hydrogen.

CO2 itself would be a good propellant if a nuclear heat source were avilable.

Thanks Rick.

Many thanks.  Some interesting material you have provided, which highlights the difficulty of attempting to create a trully closed system.

On Mars, the situation will perhaps be a little easier (easier in some respects than on Earth) for the simple reason that we would have a convenient and infinite reservoir of CO2, which can be compressed into the habitat if CO2 levels drop, or processed in a simple Sabatier reactor to produce oxygen, if O2 levels drop.

The whole process is critically dependant upon power supply.  Food production would be less of an issue given that it can be stockpiled in large amounts.  Gas balance is clearly a more significant problem and is dogged by a positive feedback effects which would appear to make active control an absolute neccesity, especially in small systems.

the system that i had in mind would have human beings on one side of the equation and tanks of artificially lit algae on the other.  The temperature of the algae tanks would be precisely controlled, as would the nutrient content of the water.  Both can be measured in real time and kept within narrow limits.  Atmospheric CO2 would pass into the algae either by bubbling air through the tanks or by feeding in neat CO2.  the only other variable is light levels.

On Mars, the food production element could actually be decoupled entirely from the atmospheric regulation system.  For example, the atmosphere of the colony could be provided by a sabatier reactor with Martian atmospheric CO2 as a feedstock and the algae food-producing tanks could be fed with compressed martian CO2 with the O2 waste product venting into the atmosphere.  In reality, it will be more energy efficient to maintain some degree of closure, recycling biologically produced oxygen into the habitat.

The key point here I suppose is that the system is at no point completely 'closed'.  It continuously exchanges gas with the Martian atmosphere and would probably need to import trace elements from Martian soil as well.  The system also depends critically upon artificial power and mechanical systems for the survival of human life.  The systems maintaining the atmosphere would therefore need a very high degree of reliability and redundancy.  The food production system would be less critical, given that the system could presumably be buffered to allow a repair time measured in years.

Soylent Green, anyone? 

There are many different species of algae, yeasts and edible bacteria, not counting the genetically modified varieties.  Eventually it should be possible to produce very palatable and nutritious foods using different blends of algal, yeast and bacterial components.

For example, one algae might be used to produce flour, which could form the basis of staples.  Yeasts could provide flavouring and B and E vitamins.  Bacteria could be used to produce cheese from an algae derived starter.

The really great things about algae as a food source are:
1) It is far more efficient in terms of its utilisation of sunlight than land based plants.  this opens up the possibility of growing it using artificial energy sources.  this would allow humans to colonise worlds which do not have abundantly available sunlight.
2) It can grow in very compact spaces, and does not need acres of expensive pressurised glass greenhouses to grow under.

When humna beings master Nuclear Fusion, algal food production and recycling (intelligent production), they can effectively colonise any solid world in the solar system, including the various moons and icy worlds of the outer solar system.

Interesting paper.  Most of the silicon on the moon is in the form of aluminium silicates, are there species of diatoms that can break this down into silicon dioxide polymers and aluminium oxides?

Whilst interesting, I do not see how diatoms like this are going to be useful terraforming the moon.  Most of the mass of their bodies is carbon, hydrogen and oxygen.  The first two are not found on the moon in quantities that are likley to be sufficient for terraforming.  Oxygen can only be produced by chemically decomposing rocks.

Most of the hard work in terraforming the moon consists of getting the enormous amounts of water, carbon and nitrogen to the moon.  After that, an oxygen atmosphere can be produced slowly by biological organisms or rapidly through photo-dissociation of water vapour or direct thermochemical dissociation of water or lunar rock.

We all depend upon technology to survive - for water, food production, shelter, transport of goods, waste treatment, etc.  Without that technology, life for most of the human race living today, would be as impossible as it is on the moon.

But this largely misses my point.  My point was, that by the time we get to terraforming Mars, it will already be heavily colonised by human beings who:
1) Do not need a terraformed planet in order to survive;
2) Do not wish to endanger their environment with the sort of massive global changes that terrforming would entale;
3) May have everything that they really want and need within the boundary of their habitats.

On this basis, terraforming would be largely cosmetic as far as these people were concerned.  It would be both expensive and risky to the existing inhabitants and would neccesarily be a long term project, which may not make much difference to the planet's ultimate holding capacity.

If we consider other worlds like the moons of jupiter, saturn, ceres, Triton, Pluto, other TNOs, etc, terraforming becomes even more marginal due to the high cost of such things as artificial illumination and the high-column density of the atmosphere required to produce breathable air on low-gravity worlds.

All things considered, most of humanity living 1000 years from now, are likley to reside in artificial habitats, not terraformed worlds, with food, clothing, manufactured goods, etc, all derived synthetically from artificial energy sources.  They will have plants and animals largely for cosmetic reasons, but their food and virtually everything they need to survive will be derived from artificial energy sources.  The further you are from the sun, the stronger this arguement gets.

I would expect that a heavily populated Mars, would differ little in its fundamental characteristics to the world that we see today.  The atmosphere may be marginally thicker, as waste heat from the many thousands of habitats raises the average surface temperature and results in outgassing from the regolith.  But human presence would not be immiediately obvious, because habitats would be generally very compact and shielded against cosmic rays by Martian regolith.  All food production would take place within compact chemical plants within the habitats, so there would be no obvious signs of agriculture or other tell-tale signs of human presence.  Only the plumes from fusion reactor cooling towers would betray the presence of human life.

A heavily populated outer planet moon or TNO, would not show significant visible signs of life, although its average surface temperature would generally be higher than one would expect from sunlight alone, again due to waste heat from habitat fusion/fission power sources.  As water is used to remove waste heat from habitat fusion reactors, there would probably be a thin, transient atmosphere of water vapour, which would snow-out on the surface.