Cause and Effect 101

by Gordon Prather
by Gordon Prather

This "breaking news" just in! There has been a continuous reduction over the past 50 years in the amount of really cold water that has flowed south along the ocean bottom in the strait between Greenland and Iceland. The eco-wackos have jumped on that discovery and are claiming that, because of that reduction in cold water current in that strait – which they blame on all you SUV-driving American soccer moms – in a few years, the British Isles will have a climate like that of Greenland or Siberia.

Before donning sackcloth and ashes, putting your SUV up on jacks in the garage, demanding that President Bush immediately implement the Kyoto Protocols and vowing to vote for Al Gore early and often in the next election, you might ask yourself, "By what logic did the eco-wackos conclude that American soccer moms are responsible for making the already dreadful Brit climate even worse?"

You might even wonder why cold water goes rushing from the North Pole past Greenland towards the equator in the first place. Well, apparently it has something to do with the seasonal differential heating of the earth's oceans – which cover about three-quarters of the Earth's surface. The seasonal differential heating results from the Earth's axis of rotation being tilted 23.5 degrees away from the vertical to the plane of the Earth's orbit about the sun. When the North Pole is titled away from the sun, we have winter in the Northern Hemisphere, while they have summer in the Southern Hemisphere, where the South Pole is then tilted towards the sun. And vice versa.

Now the surface water near the poles is always fairly cold, but when the axis is tilted away from the sun, it gets really cold up there. Colder water – which is denser – sinks at the poles and more or less moves towards the equator of the spinning planet, while the warmer surface water at the equator – which is less dense – is displaced by the colder water flowing under it. That is, the warm Gulf Stream that has been keeping the Brits from freezing their donkeys all these years is actually a surface 'replacement' current, and if there is less cold water flowing south along the ocean bottom to the equator from the pole, then there will be needed less warm water flowing north to replace it.

But, is there less cold water flowing to the equator from the North Pole? We don't know. After all, all the water on the ocean bottom is cold, only about one degree centigrade on average. And the average temperature of all the water in the oceans is reported to be only about four degrees centigrade. What scientists have reported is that – each year for 50 years – there has been less really cold water flowing south in the narrow strait between Greenland and Iceland than the year before. For all we know, the 'missing' cold water may simply be taking some other path to the equator. Ocean currents don't have rigid banks and – over time – do change their paths. And when they do change their paths, the climate on the shore eventually changes accordingly.

One of the reasons the Greenland sea floor current may have changed its path in the past is that hot spots develop along the Mid-Atlantic sea floor where lava has bubbled up from undersea volcanoes to make new sea floor and has heated the nearby water on the ocean floor to as much as 400 degrees centigrade. The water doesn't boil because it is under pressure of up to 300 atmospheres. Incredible as it seems, some bacteria – perhaps the earliest life forms on this planet – thrive there at those temperatures and under those pressures.

There is no sunlight down there, so life can't depend upon photosynthesis to make the amino acids that both plants and animals need to live. These so-called chemo-synthetic bacteria are able to oxidize the hydrogen sulfide – which is toxic to most living things – (produced by the lava bubbling up) to produce the energy that would otherwise be provided for photosynthesis by sunlight. Incredibly, these bacteria produce the same 20 amino acids that all other forms of life depend upon, so more than 300 new species of animals – including amphipods, copepods, tubeworms, snails, shrimp, crabs and even octopi – have been discovered there on the ocean bottom, happily feeding on the chemo-synthetic bacteria and the amino acids they have produced.

If the Greenland current changes its course so as to avoid such a hot spot on the ocean floor, it is not obvious how soccer moms can possibly be held responsible.

Ocean currents have been shifting course and changing the climate on shore for hundreds of millions of years, long before mankind began dumping large quantities of carbon dioxide into the atmosphere. In fact, there were large quantities of carbon dioxide (and methane and water vapor) in the atmosphere – mostly from volcano eruptions – long before there were any living things on this planet, much less soccer moms.

But the eco-wackos have seized on carbon dioxide – a so-called "greenhouse gas" – as the driver of climate change, perhaps because increases in its emission can be identified with Big Oil and King Coal, as well as with gasoline guzzling SUVs. Water vapor in the air is much the more powerful greenhouse gas and SUVs do also emit water vapor. Carbon dioxide amounts to only about .035 percent of the air by volume (methane, another greenhouse gas, only amounts to about .0002 percent) whereas water vapor concentrations can be up to four percent – 10 to 100 times that of carbon dioxide.

The water vapor percentage would be even higher, except that as the hot air containing it rises and cools, the vapor changes state from gas to liquid (or ice) and forms clouds, and when the clouds turn to rain, snow or sleet, some of the carbon dioxide in the air is dissolved and swept out of the atmosphere as well.

Which finally brings us to the theme of this column. You probably knew there were two stable Carbon isotopes: Carbon-12 and Carbon-13. (Carbon-14 is radioactive, and hence not stable.) Isotopes are atoms that have the same chemical properties but have different physical properties. About 1.11 percent of the stable carbon atoms are C-13. The rest are C-12.

However, you may not have known that there are characteristic measurable differences in the C-13 to C-12 ratio, between the isotopic concentration of carbon atoms in the non-organic carbon dioxide that gets belched out of a volcano, and the carbon atoms in the organic carbon dioxide you get by burning a tree or a bush.

Plants take nitrogen and carbon dioxide out of the air and – through the process known as photosynthesis – fixate nitrogen, eventually producing the amino acids that both plants and animals need to live. The reaction goes much faster for the C-12 isotope, so there is a C-13 deficiency in all organisms, plants and animals, living and dead. Hence, there is a characteristic measurable Carbon-13 deficiency in carbon dioxide that has been produced by burning something organic, like a tree, for example.

In fact, the Carbon-13 deficiency of all trees and most shrubs growing in cool, temperate climates is about twice that of plants growing in warm, tropical climates. Hence, measurement of isotopic carbon content of dead or fossilized plants can provide an indication of what the climate was at the time the plants lived.

There are even distinct differences in the isotopic carbon concentrations between terrestrial organic matter – which has absorbed carbon dioxide from the air – and marine organic matter – which has absorbed carbon dioxide dissolved in the ocean's surface. So, a similar analysis of the C-13 deficiency of the ocean bottom sediment resulting from dead marine organic matter can provide an indication of what the carbon dioxide levels were in the atmosphere at the time the marine organisms lived.

Now, the eco-wackos claim that it is the carbon dioxide – from whatever source, organic or inorganic – concentrations in the atmosphere that largely determines climate. But recent analyses of ocean bed sediment, going back hundreds of millions of years, more than suggest that it is the other way around. At least for the organic carbon dioxide levels, it is the climate that determines the carbon dioxide levels. Once again, it appears that carbon dioxide levels are the effect, not the cause.

Of course, the eco-wackos assume that all fossil fuels – coal, oil and natural gas – are organic in origin, and that is central to their argument that all you SUV-driving soccer moms are responsible for the change in ocean currents. You see, they claim that the global emission and absorption of organic carbon dioxide was in balance until you came along, and that by digging up all those fossils and burning them, you are upsetting Mother Nature. But on the basis of C-13 deficiency analysis of oil and gas found at considerable depths beneath the earth's surface, we now suspect that fossil fuels may not be organic in origin after all.

Nobel Laureate Sir Robert Robinson, who investigated the chemistry of natural petroleum in some detail, noted that the deeper one goes into the earth's crust to find the oil reservoir, the fewer are the signs of anything biological in the oil one finds. True, there are signs of organic activity – microbial life – in oil found near the surface. But as the depth from which the oil is obtained is increased – to the depths where microbes aren't found – the more nearly the Carbon-13 deficit disappears. That is, oil and gas near the surface may have been contaminated by the microbes that live there, but the isotopic carbon ratios for natural gas obtained from great depths is indistinguishable from the methane ejected in volcanic eruptions. It follows that the carbon dioxide produced by burning natural gas obtained from deep reservoirs is also indistinguishable from the carbon dioxide ejected in volcanic eruptions.

Irrespective of the source, there has been a considerable increase in the past 30 or so years not only in the base level of the carbon dioxide concentrations in the atmosphere, but also about a 20 percent increase in the amplitude of the seasonal variations. There is an observed correlation between increased seasonal amplitudes and both the average surface temperature, and the isotopic carbon ratio. Once again, correlation does not imply cause and effect.

All the carbon dioxide produced by such things as forest fires have the characteristic organic C-13 deficit. All the carbon dioxide produced by such things as volcanic eruptions have – by definition – no C-13 deficit. Growing terrestrial plants and marine organisms remove carbon dioxide from the atmosphere and much more is dissolved in the oceans and in rain. The effective C-13 deficit in the atmosphere is just the average of the organic and non-organic contributions that remain in the base level. But the actual measured C-13 deficit has more or less tracked the total increase in carbon dioxide. That would make sense only if the net increase to the base level was organic in origin.

That is, the eco-wackos have assumed that the carbon dioxide added to the atmosphere by Big Oil, King Coal and you soccer moms is organic in origin and so the C-13 deficit of the atmosphere would increase slightly, since the C-13 deficit of the atmosphere is just the average of what was already there plus what gets added. But if oil and natural gas is not organic in origin, then the carbon dioxide added by Big Oil and you soccer moms would not increase the C-13 deficit.

So, where does all this – if proven out for all fossil fuels – leave the eco-wackos? Well, it throws Al Gore's "Earth in the Balance" into a cocked hat. If the net increase has to be organic in origin and you soccer moms haven't started any forest fires lately, you may – or may not – be changing the climate in jolly old England by driving your gas-guzzling SUVs. But you're not upsetting Mother Nature any more than did the eruptions of St. Helens or Pinatubo.

Physicist James Gordon Prather [send him mail] has served as a policy-implementing official for national security-related technical matters in the Federal Energy Agency, the Energy Research and Development Administration, the Department of Energy, the Office of the Secretary of Defense and the Department of the Army. Dr. Prather also served as legislative assistant for national security affairs to U.S. Sen. Henry Bellmon, R-Okla. – ranking member of the Senate Budget Committee and member of the Senate Energy Committee and Appropriations Committee. Dr. Prather had earlier worked as a nuclear weapons physicist at Lawrence Livermore National Laboratory in California and Sandia National Laboratory in New Mexico.

Copyright © 2001 Gordon Prather

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