Why?

Paul Ehrlich has argued that the natural limits of ecosystems will eventually bring the human population into balance with the earth's carrying capacity. This of course is undeniable but what is arguable is how many the earth can carry, which depends on a lot of interrelated assumptions. How much each person eats or wastes, what type of food they eat (vegetarians reportedly have a tenth or some even claim a twentieth of the ecological foot-print of some carnivores) and how far the food has come are some of the obvious impacts on carrying capacity. Some not so obvious strands in the web are land clearing, grazing and desertification and their negative impact on rainfall and consequent shriveling food yields.

Even more influential is the rapid conversion of fossil carbon into CO₂which is warming the whole planet. The more people there are, the more serious the greenhouse effect and the more unpredictable the consequences. Soil degradation is mostly unseen by the majority of people who depend on it for their food. The soil is loosing vegetative cover, drying out, warming and consequently loosing organic matter and this is creating a huge extra burden of greenhouse gas in the already overloaded atmosphere. Dry land is more prone to erosion, and bare soil sheds more water while increasing flooding frequency and intensities. Phosphorus availability is declining and we may have already reached "peak phosphorous". Salinity related to land clearing is taking millions of hectares of land out of production each year.

So on the face of it the human population is rocketing up towards 9 billion by 2050 but the degradation of the means of supporting those extra 80 million people each year is forcing humans to play the extinction card. At this stage it is not overt, no government is consciously saying "people are more important than orangutans, tigers or any one of the thousands of species that will become extinct over the next hundred years." But, as one resource base is exhausted, another must be developed. Have you ever stopped to wonder why so little is being done by wealthy nations about the perpetual cycles of famine, HIV AIDS or civil wars in Africa? What does it tell you when you learn that the US is prepared to spend trillions on one war in Iraq and thousands of times less on its aid budget? Subconsciously or not, nations with the economic, political and intellectual power to do something about it, secretly view the "African tragedies" as increasing their own chances of maintaining and prolonging their luxury lifestyle into the future. How else should one interpret the nationalistic parochial approaches to global pandemics or quarantine. National Tamiflu hoards stockpiled in rich countries is subconscious, or maybe not so subconscious, eugenics. More like crude social Darwinism.

But this as a "business-as-usual" scenario, won't, and can't, last. I believe we are at a huge tipping point in human history. Humans as the problem must become their own solution. Innovation will become the norm, people must voluntarily change the way they behave and interact with the planet and all its inhabitants in new and positive ways. Propitiatory thinking will give way to sharing and cooperation. The Internet and new communications tools are planting the seeds of a huge social and political upheaval that will dwarf the industrial revolution in its scale and reach. Yes, technology will play a big part, but the new global consciousness that is already swelling will be the flower that history will deem most significant.

As a thought experiment, think of the most inhospitable desert you can imagine. How many people could it support? Well if it doesn’t rain for hundreds of years, then the real carrying capacity of that natural (un-modified) habitat is zero. No food, no water, no human life possible. Just parched baked earth and sand.

But the desert is not actually as inhospitable as it at first seems. Beetles have found ways to passively condense moisture from the cool night air in deserts, air that unlike the Martian atmosphere already contains oxygen for respiration and CO₂needed for plant growth. The temperature is hot in the day and freezing at night, but only a metre or two under the surface, it is comfortable enough for humans to live all year round. There is an abundance of solar energy. On the scale of a human family it is quite possible to modify the soil with biochar to make it highly productive. So what's the big challenge to surviving in this place if you shape it to suit your needs?

Now imagine your patch of desert with a family sized LifeBubble embedded in its harsh landscape - a vital speck of green in an ocean of burning sand. It has the technology to condense water out of the air like the Namibian beetle and recycle it to create a humid emerald ecosystem. Because the LifeBubble can be a net producer of water, the envelope of vegetation could extend well beyond the enclosed space. Plant transpiration and evaporation cool the internal space and plants important for human food can now thrive. A space of a few hundred square metres can now support a few thrifty people. Even a hundred thousand LifeBubbles would have no more significant impact on the desert ecosystem than as many large boulders.

The carrying capacity then clearly depends totally on how the ecosystem is managed and manipulated. Its would be theoretically possible to created a kelp-like tethered floating sphere with the top 1/3 breaking the surface of the ocean or a lake - yes a LifeBubble in the water. The engineering is more difficult with aquatic life bubbles than the desert type, but it is clearly possible and much easier than finding a new planet with a rudimentary atmosphere for us to colonize.

So how many people could the earth theoretically support with this scenario? Some of the Pacific islands are not much different to this concept except they have the distinct disadvantage that they wont float as sea levels rise. Their temperate maritime climate can produce an amazing abundance and diversity of food. It seems likely to me that human ingenuity will continue to push boundaries and make inhospitable places not only habitable but productive and gorgeous places to live in. The key is in developing technologies that can create and regulate ideal micro-climates that enclose human ecosystems without the need for huge energy inputs.

The LifeBubble concept is fundamental to a future that can avoid catastrophic population crashes and mass extinctions, massive and bloody wars and unimaginable famines. LifeBubbles in the arid zones and deserts could help our struggling global climate systems, reverse the process of desertification, mop up CO₂ cool the planet and bring to life streams that have not flowed for centuries.

When the time eventually comes to start new colonies in space, we could have the knowledge, wisdom and experience built up from perhaps thousands of years of creating and restoring ecosystems to set sail for new planets as competent ecosystem designers and managers, ready to seed strange, beautiful and hostile spheres with life.