Biosphere One - circa 4 billion years B.C. to the 20th Century - The Biosphere I phase preceded recent global warming changes. It saw the cradle of bacterial existence, followed, 2-3 billion years later, by a huge distribution and diversity of life forms in the orb's watery, land, and atmospheric environments. Life on this "third rock" from our sun has helped to create the kind of world we have until lately enjoyed as simply the natural condition, with blue skies and seas, an oxygen rich protective blanket of air, and friable soil filled with organisms that greatly aid in the land's fertility. The interconnected web of life in Biosphere I has penetrated from more than a mile underground to several miles into the atmosphere and has pervaded all levels of ocean depth as well as of land surface.

Biosphere Two - Begun in 1991, Biosphere Two was the largest (3.15 acres) man-made closed living environment ever developed. Its first project, a two-year experiment ending in mid-September, 1993, involved research with eight humans, a number of animals, and multiple plant species quaranteened within a complex virtually airtight living system separated from the rest of the planet. It may be regarded as the first test of more or less total control of the environment by our species. It ended in failure. There were too many variables, and some were not adequately accounted for in the planning or execution. Carbon dioxide levels fluctuated greatly. Oxygen levels decreased. All vertebrates introduced to the project died except for the humans. Three times as much energy was required to cool the air down as the solar energy heating that occurred through Biosphere Two's glass panels. A second, final closed system experiment in Biosphere Two was begun in 1994, but, due to disputes over the financial management of the project, this one ended after only six months. Despite the shortcomings of Biosphere Two's initial trials, much was learned from these tests. In addition, the people who stayed in the two-year experiment enjoyed great health enhancement, assumed to be due to their having much better diet and exercise regimens than they had been used to on the outside. Less ambitious research has continued at Biosphere Two down to the present.

Biosphere Three - circa roughly the 20th Century through the mid-22nd Century - This is our current transitional Earth phase. It is characterized by an unprecedented exploitation of the environment to sustain a huge and growing human population and the vibrant industries and economies on which it depends. Temperatures are apparently rising at a faster rate than has previously been experienced by our species. Though the majority of climatologists concur that this is due largely to human activity, some scientists disagree. Latching onto either controversial aspects of climate change theory or accusations and countering arguments by the diverse nations to justify inaction, few political bodies today have the will to take decisive and constructive steps. The situation may be not unlike that prior to World War II, when only a handful of statesmen and military leaders saw the necessity to do anything about the dual rises of Nazism and Japanese imperialism. Although many are becoming acquainted with the predicted consequences if nothing positive is done, for instance a several degrees F rise in average temperatures at the poles, species die-offs, new ocean chemistry, inundation of many coastal areas, increased frequency and severity of storms, greater disease spread, and higher insurance claims and rates, few in this Biosphere Three phase can agree that substantial preventative measures need to be taken or what they might be.

Biosphere Four - circa mid-22nd Century till... - This phase will be characterized by widespread appreciation of the natural consequences of both global warming and unchecked population growth. Their extent will be profound enough that, as with the onset of the last great war, not many will be unaffected or fail to understand that a catastrophe of monumental proportions has begun. The majority of areas near the ocean's current boundaries, roughly 50% of human development, will be underwater or threatened by rising sea levels. Between 30-40% of species alive when older human generations were born will have ceased to exist. Few naturally occurring (as opposed to aquaculture) fish will remain in the seas. Droughts of great intensity and duration will be as destructive as the massive floods occurring in other areas. Hurricanes of more frequency and severity than known in the early 20th Century will pummel the already threatened coastlines as well as drenching regions far inland. Agricultural viability will be difficult to sustain in many places that now are considered productive farmland. Tropical diseases will make great headway in the currently temperate zones. Population's rise will have ceased. The number of humans will instead have begun to plunge. Glaciers will have melted in most higher elevations around the world. The vast ice sheets of Greenland and Antarctica will also have seen substantial melting. Ocean currents will be forming new, unforeseeable patterns, creating as yet unpredictable micro-climates. Reliable fresh potable water will be unavailable to many. Climate and resources related wars will have broken out. Many more failed states will have occurred. There will be great political and economic instability. Bleak as this description may sound, it could be too optimistic.

Biosphere Five - From the depths of the Biosphere Four phase, an acknowledgment will finally be made that serious action must be taken to halt the worst excesses of the 20th and 21st Centuries. From their effects, humans will by now be on the defensive in most areas of the world. Efforts will be made to shore up a population remnant in demographically as well as environmentally sustainable ways. Unprecedented technological innovations will be employed to preserve and enhance relative climate stability. In essence, we shall be embarked on the "terraforming" (Per NASA, "the process of transforming a hostile environment into one suitable for human life") of Planet Earth. This hypothetical next global phase will see our species being the successful managers of our unique pearl of a world, taking over from nature as the sphere's responsible partner/administrator. It will still require many generations to correct some of the worst repercussions of the current period. With luck, however, homo sapiens may yet, by the skin of its collective teeth, hold onto a tenuous Biosphere Five existence through the balance of the present millennium.

(The preceding has been a Happy Halloween special. We hope it need not be taken seriously. Larry)