6 Billion™ - The Game Of The New Millennium

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BNBG - Going It Alone
BNBG - 6 Billion (The Planets & The Asteroid Belt)
BNBG - 6 Billion (Exploring Our Demographic Future)
BNBG - 6 Billion (A Brief Demographic History)
BNBG - 6 Billion (Getting Animated)
BNBG - 6 Billion ("Overpopulation" post to KurzweilAI.net)
BNBG - Game Theory
BNBG - 6 Billion (Per Ardua Ad Astra)
BNBG - 6 Billion (Profile - David Coutts)
BNBG - 6 Billion (The Cassandra Prediction)

External Links
See the Java version of Solarpop by Craig Cleveland

6 Billion™ - Exploring Our Demographic Future
(This is background information only - you do not need to know this to play "6 Billion™")

"There is no law of physics or biology that forbids cheap travel and settlement all over the solar system and beyond."     Freeman J. Dyson (1999), Professor Emeritus of physics at the Institute for Advanced Study Princeton University, from "The Sun, The Genome and The Internet"


In assessing the realism of the 6 Billion™ framework for our future population growth, it is necessary to decide when the first billion (or million, in my worst-case scenario) becomes established in space and what rate of growth will apply to them. 

The examples below are intended to highlight the fact that, whilst Earth will slow its population growth, humans capable of living in space will not be so restricted and will be more likely to encourage population growth with all the advances of science at their disposal (reinforced by typically high "frontier" growth rates). Just what is "realistic" nobody knows, but it's surely worth exploring... Before you rush to email me with how ridiculous any or all of these examples are, try creating your own "realistic" example. If you don't feel like doing so, then don't bother emailing me. If you do try, I'd be happy to hear from you but only if you provide the reasoning behind your own example(s). 

Throughout this article, I use the Population Doubling Mechanism  which so neatly ties population doubling to population doubling timeframes. This is so simple an approach for exploring future population growth that I'm simply amazed that no dedicated Web sites about population growth use it. If you know of any apart from mine, I'd like to know about it. This method is just as valid for analysing the demographic possibilities for Australia, the USA, the global Earth population, or the future population of our Solar System. If you think that population doubling is not a valid mechanism for exploring population growth - please do your homework... If you think that the series 1  2  4  8  16  32   64   128   256   512   1024 is not exponential (or in some way linear) then please do your homework...If you think we'll never colonise our own solar system I'd be fascinated to hear from you, but only if you provide your reasoning. If you prefer to assume Zero Population Growth for Earth, or even Negative Growth, try reading my article The Cassandra Prediction before you contact me..

Example 1

If 1 billion people were sent out into the Solar System by 2100 (leaving 11 billion on Earth), and could sustain a modest 2% growth rate, they would quadruple by 2170 - making 4 billion people in space! Possible? Unlikely.  

Time 2100   2170   2240 ... 2380   2520
Earth 11 ... 15.6 ... 22   44   88
Time 2100 2135 2170 2205 2240 ... 2380 ... 2520
Rest Of Solar System 1 2 4 8 16   256   4,096

Table 1. Assumed Rapid Earth Exodus (in billions). Planet Earth grows at 0.5%, doubling every 140 years. The rest of the Solar System, growing at 2%,  doubles every 35 years (or 4 times every 140 years). Hence, in this scenario, game-turn one ends between 2205AD and 2240AD (when a total population of 24 billion is reached). 

Note that 6 Billion™ does not assume a rapid rate of emigration from Earth, but does cope with such a scenario. 

Example 2

More likely, I think, is that fewer people would leave Earth for life in space and many, many more people would be born in space (no longer Earth people). Let’s try 0.5 billion leaving Earth with a fast 3% growth rate, and Earth slows down its rate to 0.1%. That’s a doubling rate of 25 years for those in space, so our 0.5 billion would double 4 times by 2200 - making 4 billion living in space to Earth’s 11.5 billion growing at 0.1%!  

Year 2100   2150   2200       2800
Earth 11.5 ... 12.07 ... 12.69       23
Year 2100 2125 2150 2175 2200 ... 2500 ... 2800
Rest Of Solar System 0.5 1 2 4 8   32,768   134,217,728

Table 2. Assumed Rapid Solar System Growth (in billions). Planet Earth grows at 0.1%, doubling every 700 years. The rest of the Solar System, growing at 3%,  doubles every 25 years (or 28 times every 700 years). With rapid growth in the rest of the Solar System, the 8 billion in 2200AD double to 16 billion by 2225AD so game-turn one would end between those dates (when a total population of 24 billion is reached). 

Note that 6 Billion™ does not assume such rapid population growth in space, but does cope with such a scenario for a 'short' timeframe. As each game of 6 Billion™ ends with populations in the low trillions, this situation would be reached between 2400AD and 2500AD with a sustained 3% growth rate. It is unlikely such a high growth rate would be sustained for long, but it is conceivable that even higher growth rates might be possible in the short-term.

Example 3

A worst-case scenario (ignoring the possibility of never colonising space) should assume a slow Earth exodus and slow population growth in the solar system (but faster growth than Earth). Assume 1 million in space by 2100, growing at just 1%. Earth again grows slowly at 0.1%. 

Year 2100   2150   2200       2800
Earth 11,999   12.07 ... 12.69       23,998
Year 2100 2170 2240 ... 2590 ... 2730 ... 2800
Rest Of Solar System 1 2 4   128   512   1,024

Table 3. A Worse-case Scenario For Space Colonisation (in millions). Planet Earth grows at 0.1%, doubling every 700 years. The rest of the Solar System, growing at 1%,  doubles every 70 years (or 10  times every 700 years). Hence, in this scenario, game-turn one in 6 Billion™ ends just before 2800AD (when a total population of 24 billion is reached). 

Note that 6 Billion™ does not assume such slow population growth in space, but deals comfortably with such a scenario.

Example 4

Realistically, any growth rate will slow as the limits to growth are realised. Conservatively, I would anticipate humanity  reaching a population of 1 billion in space (through migration from Earth, and inherent population growth) by 2200AD. Earth's population would probably still be close to 12 billion. Conservatively again, I would expect the space population of 1 billion to experience an average sustainable growth rate of at least 1% for the next 280 years, slowing to 0.5% for the next 560 years. At 1% for 280 years, the 1 billion would double 4 times to 16 billion. At 0.5% for 560 years, the 16 billion would double 4 times to 256 billion. 

During the entire 840 years from 2200 to 3040AD, I assume Earth's growth rate to be a maximum of  0.1%, with the population doubling from something like 12 billion to 24 billion. 

Year 2200       2480       3040
Earth 12       15.85       24+
Year 2200 2270 2340 2410 2480 2620 2760 2900 3040
Rest Of Solar System 1 2 4 8 16 32 64 128 256

Table 4. A Conservative Scenario For Space Colonisation (in billions). Planet Earth grows at 0.1%, doubling every 700 years. The rest of the Solar System, growing at 1%,  doubles every 70 years until 2480AD, then slows to a 0.5% growth rate and doubles every 140 years until 3040AD. During that time, Earth doubles just once. Hence, in this scenario, game-turn one in 6 Billion™ ends between 2410AD and 2480AD (when a total population of 24 billion is reached). 

Note that 6 Billion™ does not assume conservative  population growth in space, but deals comfortably with such a scenario.

The 6 Billion™ Scenario

6 Billion™ is concerned with counting humans in our Solar System. It does not try to portray:

What 6 Billion™ does is to focus on the likely scale of human populations throughout our own solar system, and highlights that these numbers are achieved through the sound mechanism of population doubling. No other game does this. It appears to me that few people take this scenario seriously, and yet it is such a likely scenario. 

6 Billion™ represents populations via its 10 population tracks - that's one for each planet (Pluto has recently been re-classified as a dwarf planet) and one for the Asteroid Belt.  Each population track allows for surface (or sub-surface) populations on the small planets (Mercury, Venus, Earth, Mars and Pluto) and the moons of the giants (Jupiter, Saturn, Uranus and Neptune). Plus, artificial colonies can be built in orbit around each planet or moon, and also in the same orbit around the Sun as any planet-moon system. The Asteroid Belt is ready-made for colonisation, and encircles the Sun. If you feel that the Kuiper Belt should be included, add another population track. If Planet X is ever discovered, add yet another population track. You can buy additional decks of playing cards which you can then modify as required, and create your own new population tracks.

As 6 Billion™ recognises that all population growth is subject to "limits to growth", the game ends with our Solar System population typically in the low trillions. Regardless of which of these examples you feel is closest to reality, 6 Billion™ deals with them all (within limits to growth). Not bad for a game...and a pretty good model of our future reality, in fact. 

Sometimes I feel that 6 Billion™ is so original in its subject -matter, and in the treatment of that subject-matter, that it asks too much of its audience. The players' imaginations, conditioned to think of population growth as a bad thing, fail them. Some, ignorant of the truly exponential nature of population growth, see such growth as linear. Some, conditioned to think of the colonisation of space in terms of other stars, and Earth-like planets, fail to see the likelihood of the colonisation of our own solar system. Some are ignorant of the availability of resources in our own solar system. Some simply cannot see beyond the Earth, and all its woes.  

Other Scenarios

The  6 Billion™ model also works historically, as demonstrated by the Hunter Gatherer To Civilization variant. 

I am currently working on another variant which will easily accommodate a future where mankind bifurcates into various new species (and even creates one or two new ones). Note that population doubling will apply to them too! With regards to the arrival of aliens...it makes for a great story but I'm not holding my breath on that one.

As stated above,  6 Billion™ does not exclude the possibility of colonising the stars during the timeframe of the game. However, as each solar system colonised by humanity would experience population growth using the same population doubling model portrayed in 6 Billion™, you would effectively be playing multiple games of  6 Billion™ simultaneously. Or you could simply represent each solar system as a population track and, with minor tweaking of the cards, play interstellar 6 Billion™.

Most interstellar space games (which usually fabricate FTL travel to work) fail to focus adequately on matters such as sustainable population numbers and population growth. Instead, they all focus on the exploitation of resources in order to build battle fleets and space armies, and fight wars. It is fair to say that military spending does consume a disproportionate amount of each Earth nation's budget, but there is a heavy over-emphasis on war in these space games. In evolutionary terms, the real history of humanity is a demographic one (see my article A Brief Demographic History Of Humanity), not a political or military one. War is the minor partner in the Four Riders Of The Apocalypse (War, Famine, Pestilence and Death). For example, between 1945 and 1983 only 2 million people died due to war and nearly 20 times that number died due to want (lack of food, water or sanitation). 

The main purpose for exploiting resources (for any species) is a demographic one. Usually this is perceived as aiming to sustain a population, but in practice (for humanity) it means sustaining an increase in population (even after taking the Four Riders Of The Apocalypse into account). 


Any demographic scenario for a species which does not assume population doubling will result in the extinction of the species in question (via Negative Growth), or the eventual evolutionary marginalisation of the species in question by more advanced Earth species. The species in question is humanity. See The Cassandra Prediction for more detail on these arguments.

Therefore, humanity must assume that population doubling will continue, or else accept its own demise. The only realistic scenario which allows us to assume continued population doubling for humanity is the colonisation of space. In the short-term, and to most efficiently exploit the resources available to us in nearby space (the Sun, planets, asteroids and comets), we must colonise our own solar system. Once we have done that, our future as a species is looking significantly more secure.

In short, in evolutionary terms, the 6 Billion™ scenario is humanity's best bet. The timeframe is up to us.

For a list of articles by me, see the Articles page.

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Last modified: 08 November, 2009