Fire and Ice
Some say the world will end in fire,
Some say in ice.
From what I’ve tasted of desire
I hold with those who favor fire.
But if it had to perish twice,
I think I know enough of hate
To say that for destruction ice
Is also great
And would suffice.
– Robert Frost
Although the Earth’s climate has cycled between cold and warm periods, the current Quaternary ice age has persisted for 2.5 million years. Without intervention by man, the mild climate of the Holocene epoch, the 10,000-year period in which glaciers have retreated and human civilization has blossomed, would surely give way to renewed glaciation over much of the Earth (NY Times). The central thesis of global warming is that the Industrial Revolution, which has pumped greenhouse gases into the atmosphere for 200 years, has overwhelmed natural cycles and tipped the world into a new and dangerous warming trend.
Science Daily reports that studies by some climatologists indicate human-induced warming began far earlier than previously thought. Based on physical evidence and computer climate models, they say that “between 5,000 and 8,000 years ago, both methane and carbon dioxide started an upward trend, unlike during previous interglacial periods. . . . The introduction of large-scale rice agriculture in Asia, coupled with extensive deforestation in Europe [produced] methane from terraced rice paddies and carbon dioxide from burning forests. . . . In turn, a warmer atmosphere heated the oceans making them much less efficient storehouses of carbon dioxide and reinforcing global warming. . . . The cumulative effect of thousands of years of human influence on climate is preventing the world from entering a new glacial age.” Is it possible that pre-industrial man might have been able to achieve a prolonged Holocene epoch without consciously trying to do so, but that industrial man will not be able to prevent runaway global warming, despite taking the most desperate measures?
What if mankind’s ticket on spaceship Earth is just for a short flight, perhaps a million or so years of its multi-billion-year journey. If so, surely the human passengers could not possibly have a lasting effect on planetary climate. Aren’t there much more significant, much longer-term, much more powerful forces at work on the climate that dwarf the influence of man? Consider the “Milankovitch Theory.” Milutin Milankovitch compared three cycles of variation in Earth-sun geometry: the shape of the Earth’s orbit around the sun (eccentricity, ~98,000-year cycle), the angle of Earth’s axis to the plane of Earth’s orbit (obliquity, ~41,000-year cycle), and the direction of the Earth’s rotational axis (precession, ~21,000-year cycle) — three cycles in which the Earth’s orbit varies from a circle to an oval and during which it tilts and wobbles like a spinning top — compared to the Earth’s climatic fluctuations over the last half a million years. He found that variations and combinations of these three cycles correlated with extreme variations in Earth’s climate, from ice ages to periods of warmth, probably because of variations in the amount of solar radiation reaching Earth.
In addition to the Milankovitch cycles, there are ~11-year sunspot cycles apparently related to ~22-year magnetic pole reversal cycles, and ~200-year solar grand minima cycles, and ~100,000-year solar magnetic activity cycles, all of which cause solar radiation output to vary, as well as cycles of cosmic ray flux and variations in the heliosphere, which occur as the Earth passes through arms of the Milky Way during the solar system’s 226 million-year orbit around the galaxy, and when it moves above and below the protection of the galactic plane and is exposed to the galaxy’s bow shock, every 64 million years. All of these phenomena may affect the Earth’s climate. Other forces affecting climate include volcanic activity, oceanic currents, and asteroid and comet impacts. In the long run, will the Earth continue to cycle between cold and warm periods, influenced more by the profound natural forces described above than by man and his civilization? Yes, it probably will. And just as surely, those who “say the world will end in fire” will be proven correct, when the sun, in its old age, becomes a red giant, expanding to engulf the Earth. So, does that mean it’s pointless for man to take desperate measures to reduce the level of carbon dioxide and other gasses he pumps into the atmosphere?
No. What we do may not count in the long run, but it counts now, during the Holocene epoch, when we and our children and hopefully our grandchildren (not to mention a myriad of other creatures large and small) inhabit the Earth. All of the recorded history of our civilization has occurred during this brief period of climate stability. If we unleash runaway global warming, it will be of little solace to us that natural cycles of the Earth, the solar system, or the cosmos may eventually cool things down again, long after we have passed away. Billions of years from now, the Earth’s ultimate fate may be to end in fire, but that does not have to be the fate of our civilization in this, our 21st century.
UPDATE: Harsh winters in some areas, stolen emails that some read as proof English climate scientists cooked data, and a news reporter’s error about when Himalayan glaciers may disappear have prompted “deniers” to claim that the whole case for global warming has been exposed as a hoax. They’re wrong. In the first place, there’s a big difference between seasonal local weather and long term worldwide climate change. Cold weather in one place or another on the planet, or even an entire year in which average temperatures decrease rather than increase, does not contradict global climate trends measured over decades and centuries. Earth’s climate is trending warmer.
Secondly, the evidence for global warming does not depend on data from any one institution. There are many research centers where scientists collect and analyze climate data, such as the Japan Meteorological Agency, the Netherlands Environmental Assessment Agency, Australia’s Climate Change Research Centre, and in the U.S., the National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA), from whom the chart reproduced here, which plots mean worldwide temperatures over more than a century, was obtained. Global warming is not a hoax perpetrated by scientists at a university in East Anglia, UK. It is a fact confirmed by literally thousands of climate researchers worldwide, many of whom contribute to reports of the United Nations Intergovernmental Panel on Climate Change (IPCC) and who are members of the U.S. National Academy of Sciences, whose National Research Council confirms as “settled facts” that “the Earth system is warming and that much of this warming is very likely due to human activities.”
And thirdly, although a reporter’s misquote of a scientist as to when Himalayan glaciers will disappear was printed in an IPCC report, that does not invalidate the entire report, nor is there any serious debate among climate scientists about the fact that the glaciers are indeed melting rapidly.
UPDATE2: The New York Times reports that the fifth in a series of investigations “exonerated the scientists caught up in the controversy known as Climategate of charges that they had manipulated their research to support preconceived ideas about global warming. . . . All five investigations have come down largely on the side of the climate researchers, rejecting a number of criticisms raised by global-warming skeptics. . . . Some of the scientists were forced to admit to poor behavior, such as chortling about the death of one climate skeptic. But were the researchers guilty of any scientific misconduct? ‘On the specific allegations made against the behavior of [University of East Anglia Climate Research Unit] scientists, we find that their rigor and honesty as scientists are not in doubt . . . .’”
[NOTES: A portion of the above post also appears on the "Twelve Crises" page, which provides additional information about the climate crisis and others of the multiple, simultaneous crises we face.]