Humans have occupied only 1 percent of the earth's existence

by Peter Schwartzman

Vignette #2

Imagine that you have just woken up from a refreshing sleep. It is 8am sharp, the time that you almost always wake up, and you have a busy day ahead of you. If everything goes as planned, you'll get everything you need to get done and you'll promptly hit the sack again at midnight. Now let's say that your day does go as expected, except for a very minor change. Instead of beginning your ''sheep counting'' at exactly midnight (12:00:00), you fall asleep one second earlier (specifically 11:59:59) still intending to wake up at 8am. Does this alteration of your plans seem noteworthy? Probably not.

How about if you continued this pattern for a year, i.e., going to sleep one second early each successive night and in so doing decreasing the amount of sleep you receive? Would it seem significant then? Well, if you were to do this, you would only be sleeping about six minutes less at the end of a period of a year-- still, not too spectacular. In summation, one second of a day doesn't seem to matter much to humans. Yet, we shouldn't be so easily convinced.

1 One second is enough time for lots of important and significant events to occur. A jetliner generally travels a mile in only 6 seconds; the orbiting Space Shuttle travels about 29 miles in the same time. Amazing at it may seem, sun light travels almost 200,000 miles in one second, which means that it could go completely around the earth more than seven times in one second or all the way to earth in only eight minutes. On the biological front, one second is enough time for 2.5 million divisions of red blood cells. But while these occurrences may seem remarkable on time scales easily recognizable by humans, equally impressive is a more directly human event that occurred on geologic time scales.

Some 200,000 years ago, modern humans (a.k.a., Homo sapiens sapiens) came into existence. Their arrival came by way of a long evolutionary journey beginning some 3.5 billion years earlier with the onset of unicellular life; the earliest fossils of photosynthetic cyanobacteria (cyan, meaning ''dark blue'') date back this far. Whether this journey culminates in this Homo's arrival or continues in directions and ways that are material for the today's science fiction thrillers, it is arguably true that the earth has been transformed by our species in a multitude of ways, many of which are only beginning to be understood.

2. In only a very short period of time, these two-legged terrestrial organisms that are commonly referred to as human beings have spread throughout all parts of all but one frozen continent and, in so doing, have greatly altered environments in all corners of the globe. And while these alterations have been incredible in scale, particularly since the Industrial Revolution of the 18th century, it is critically important that humans now take notice of the extraordinarily short amount of time that was required for this anthropogenic (i.e., human-driven) global transformation. In fact, humans have been on the earth for much less than one percent (specifically, 0.0044 percent) of the earth's history and have taken a much, much smaller percentage of time to transform the earth. Relating back to a typical human day, and taking the earth's lifespan of 4.5 billion years as a full day, humans have only been on the planet for 6 minutes and done most of their damage to the earth's various ecosystems in less than one second (precisely, 0.48 seconds). Quite a difference -- one second versus one day -- and one second doesn't matter, huh?Well, while this incredible revelation takes its time to settle in, I ask whether the reader can think of a recent news story that turned on a similarly small margin of difference. Of course, the quest for the 2000 U.S. presidency did. Everyone with a television set can probably recall the exact margin of difference in vote tallies between the two candidates, both at a national level, and more likely, in the hotly contested state of Florida. Well as it turns out, there are great similarities between the 2000 election results and the time scale of human existence -- an unusual yet revealing juxtaposition. Now for the recap.

November 7th, 2000 will go down in U.S. history as one of the key political dates of our nation. The outcome of the presidential election, although announced prematurely by a few networks, remained ''too close to call'' for a few days after the last voting booths closed. Due to this uncertainty, many citizens, fueled by the media, entered a state of mild panic and anxiety. They wished and prayed for closure, fearing that our nation was vulnerable during this period of incertitude. Tensions only intensified as the candidates squabbled and the parties sought legal vindication. In the end, after weeks of impassioned public and legal appeals, Vice President Albert Gore was cajoled into conceding. George W. Bush was going to be our next president.

With the concession, the election finally appeared settled, yet much more remained to be resolved. Outside of the charges of ambiguous and tricky ballots and the seemingly much more egregious and pernicious claims of racial profiling and obstruction, one other characteristic of the election warrants particular attention -- the Florida tally. Officially Florida, in what turned out to be the pivotal state, was won by George W. Bush (G.W. from now on) by a margin of 537 votes. Now while 537 votes may appear to be a sufficient margin to decide an election, actually a closer look reveals something quite amazing. Almost 6 million Floridians (actually 5.96 million) registered a vote in the 2000 U.S. presidential election. So 537 votes amounts to only 0.01 percent of the total votes cast. In other words, G.W. received one more vote than Gore for every 10,000 votes recorded. Translated into 100 meter racing terms, if G.W. ran a time of 10.000 seconds, Gore ran it in 10.001 seconds, something only the finest cameras in the world could detect. Yet, despite the incredible closeness of this election, ''to the victor went the spoils'' or, in absolute terms, to the victor went all of Florida's 25 electoral votes, nearly every one of which was necessary to give Bush the White House.

So having thus heard a rehash of the 2000 election, something I am sure you were looking forward to, what possible similarities and connections could this have with humanity's existence on earth. Well, first, if humans can begin to come to terms with the closeness of the election tally, something that is tangible -- that is, everyone can envision what it takes to count the votes - perhaps we can begin to understand human time scales in relation to geologic times scales. Unfortunately, humans have extremely limited ability to perceive time scales of this size. We didn't evolve in a world where such capabilities were necessary or even advantageous -- geologic events, such as large meteor collisions, just occur too infrequently. Despite this, humans are beginning to show that they can have global, and irreversible, impact. In order to begin to understand how recently humans arrived on the earth, compare, in percentage terms, the 0.0044 percent difference in the Florida election results to that portion of the earth's history that human have inhabited it (specifically, 0.01 percent). And small as these percentages are, consider how short the time that humans have been engaged in heavy industrialization and ecological change on a global scale -- 250 years, or one-two-millionth of the earth's history. Another revealing statistic relates to the percentage of their history that humans have been engaged in industrialization. On this measure, it turns out that it has taken humans only 0.01 percent, or fractionally 11 seconds of the day that they have been in existence, to modify the earth in such substantial ways. Clearly, we are living in very, very unique times and thus we should be circumspect about further modifications of our environments.

Second, as the first couple hundred days of G.W.'s tenure suggests, the implications of the outcome of an election can be substantial; one only need to consider the large tax cut, national abortion policy (via the Global Gag Rule), and national energy strategy to observe some of the key differences between a G.W. administration and a Gore administration. Thus, a relatively inconsequential difference in a quantity (here votes) can have a demonstrable impact of national governance. Similarly, a seemingly small change in human lifestyle -- such as the widespread use of motorized vehicles in the 20th century -- may be sufficient to disrupt natural systems and processes including, the greenhouse effect, the stratospheric ultraviolet screen, and wildlife migration. Ultimately, we conclude that all changes, even small ones, have to be carried out slowly and thoughtfully, otherwise damaging and dangerous unintended outcomes are possible; something perhaps Ralph Nader voters in Florida, all 96,000+ of them, are left thinking to this day.

Finally, the election results also teach us that a small margin of victory in an election can have far reaching effects and so can a short period of human history. Yet, we live in a world today that is changing extremely quickly relative to most of earth's history. The 2000 election confirms that within a matter of a couple of days, many Americans were fearful of political instability, if closure wasn't brought to the election. Similarly, studies of geologic climate episodes suggest that the Earth is also capable of reaching thresholds which result in extremely accelerated rates of change. Specifically of concern are those changes which will greatly disrupt environmental systems and processes. The sooner we come to this conclusion, the sooner we can begin to recognize how significant our collective day to day activities are. Additionally, we will begin to see why the sentiment, ''oh, humans have been here a long time and we'll be here for a long time to come,'' is likely misinformed and terribly short-sighted.


1 If you reduced the time you spent sleeping by 2 seconds every night, it would take you just about 40 years to evaporate all 8 hours of sleep.

2 I use the term ''arguably'' here very strongly. In many ways, early forms of life, such as the blue green algae, which reigned over the earth millions of years ago, more significantly caused changes in biological and atmospheric systems much more so than humans have. For instance, while humans in the 200,000 years have likely altered only one percent of the earth's gases in an demonstrable way, the primeval algae very likely substantially affected global oxygen concentrations in ways that spawned massive biological expansion of oxygen-craving species.

Uploaded to The Zephyr Online September 11, 2001

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