Saturday, February 3, 2007

Skipping Stones: A Perspective on Global Warming


Skipping Stones: A Perspective on Global Warming

By G.W. Burrows



By evaluating changes in climate or temperature over shortened

periods, such as decades or centuries instead of hundreds of

thousands or even millions of years, we either overestimate or

overstate the changes that might or might not be occurring.



Sci-Tech Today

June 3, 2005



 

The contributions of human activities to global warming is a topic of

continuing and intense debate. Unfortunately, the vast majority of

articles and reports on the effects of anthropogenic carbon dioxide

are overstated and exaggerated.



The debate has raged on about the causes and effects of global

warming, but the first question to ask is whether global warming even

exists.



Certainly it does, because without global warming, the earth would be

a much colder place. A good example is our closest neighbor, the

moon, where, even in direct sunlight, without an atmosphere there are

no molecules to absorb and retain the incoming heat from the sun.



The earth's atmosphere contains several gases, all of which have the

capacity to absorb heat energy in varying degrees. The most common

gases are nitrogen, oxygen, water and carbon dioxide. There also are

trace gases such as argon, methane and hydrogen, but their

concentrations are all much less than one percent.



Periodic changes in temperature give rise to climates that vary

widely from polar regions to the tropics. Climate is caused by more

than just global warming. The main causal factors of climate change

are the eccentricity of the earth's orbit around the sun, the tilt of

the rotational axis and its wobble.



Sun spot activity, ocean currents and albedo (whiteness) also

contribute to climate and climate change. The issue that has to be

addressed is how much of an effect carbon dioxide has on climate

change.



Experts agree that the earth's climate is primarily caused by the

distance from the sun, the shape and changes in the orbit and tilt of

the rotational axis. As long as the sun continues to burn, we will be

warm. Astronomers believe that the sun is middle aged and we have

approximately 4 billion years to go before it turns into a white

dwarf.



If you believe mainstream scientists, the earth's age is estimated to

be 4.5 billion years old. For the first billion years or so, the

earth was a hot and barren place with no oxygen in the atmosphere.

Since there was no oxygen, there was also no ozone. But after a

billion years, life began to form, the climate stabilized and oxygen

resulting from photosynthesis began to occupy the atmosphere.



Since that time, the climate has remained stable and conducive to

various life forms. The oceans have never frozen nor boiled. During

that time there have been changes in average temperature, sometimes

warmer and sometimes colder than our present-day climate.



Climatological studies of ice core samples have shown that about

every 100,000 to 150,000 years, the earth goes through a relatively

short period of warming followed by a longer period of cooling,

including an ice age. The warming period is approximately 20,000

years long and the cooling period lasts about 100,000 years.



During the last cooling period, ice covered the northern and

southernmost areas from 45 degrees North and 45 degrees South, to the

poles. The middle latitudes remained free of ice, therefore warm and

hospitable to most life forms. The last ice age ended approximately

20,000 years ago and the earth has been warming ever since, so it is

no surprise to expect that the next ice age is not far off.



Since the last ice age, the climate has warmed about 16 degrees

Fahrenheit and the sea level has risen approximately 300 feet. Humans

have only been around for about 1.75 million years. The warming and

cooling cycles were happening long before human existence.



Even more recently, the last ice age ended and warming began

thousands of years before the industrial revolution. Current changes

in temperature and climate have been blamed on CO2 production from

the industrial revolution, which began only 200 years ago, but

numerous reports have compared CO2 atmospheric concentrations over

the last 200 years in an attempt to prove the relationship between

the concentration of CO2 and the increase in average global

temperatures.



So what effect have human activities had on climate? To some extent,

quite a lot. Building large cites creates "heat islands," which cause

localized changes in weather. Massive deforestation (for example, in

the tropics) causes changes in the hydrological (rain) cycle.



Pollution contributes to changes in atmospheric chemistry; for

example, smog and particulates produce haze and ozone as well as

other pollutants such as NOX (various nitrogen oxides). Refrigerants

are blamed for destruction of ozone.



But what about carbon dioxide? Produced by all forms of combustion

and fermentation, CO2 has been the focus of debate on climate change

to such an extent that controls on CO2 production have been connected

to world economics (Kyoto Treaty) and pollution bartering.



At the present time, carbon dioxide makes up approximately 0.03

percent (or 300 parts per million) of the earth's atmosphere. In and

of itself, that number is small when compared to the other major

gases in the atmosphere. For example, oxygen and nitrogen are present

at 21 and 78 percent respectively.



To obtain a sense for how much heat carbon dioxide absorbs and

therefore contributes to global warming, the following information

must also be considered.





More than 98 percent of all CO2 in the atmosphere is produced by

sources other than by man. For example, CO2 is produced by forest

fires, volcanoes, fermentation and animal and plant respiration.



Carbon dioxide does not remain in the atmosphere. It is absorbed in

the oceans, lakes and rivers and is used by marine life to produce

shells and food. It is also used by terrestrial plants to produce

cellulose, sugar and other plant products.



Carbon dioxide is an essential and beneficial nutrient and is

actively involved in a dynamic, not static process.



By comparison, water is present in the atmosphere in amounts varying

from a few tenths of a percent in desert areas to as much as 4

percent in humid tropical areas. The amount of atmospheric water

content changes dramatically with temperature and air pressure.



Clouds and fog are made up of water and 70 percent of the earth's

surface is covered with water. Approximately 500 billion tons of

carbon dioxide and carbon monoxide are added to the atmosphere each

day, of which 98 percent is naturally produced.



In other words, only 2 percent is anthropogenic. Around 1.16 billion

tons of water is evaporated each day. At any given time, there are

106 billion tons of carbon dioxide and 12.9 x 106 billion tons of

water in the atmosphere.



And so the important question is "What do all of these numbers mean?"



First, there is a lot more water in the atmosphere than CO2. Second,

the amount of CO2 pumped into the atmosphere by human activities is

small when compared to the amount of water already in the atmosphere.



Finally we also must evaluate how much heat energy both carbon

dioxide and water are capable of absorbing. Pound-for-pound, water

absorbs two times more heat energy than CO2. The difference comes

from how much vibrational energy the oxygen-hydrogen (OH) bonds

absorb than that of the carbon-oxygen (C=O) bonds.



What then can we derive from all of the different information on

global warming?



First, all of the data presented are factual, accurate and generally

accepted by the established scientific community noting that many of

the absolute numbers vary slightly depending on the source.



Global warming does occur as a result of all atmospheric gases

absorbing and retaining heat energy from the sun.



Heat also is absorbed by land surfaces and reflected by snow, clouds

and other light colored surfaces.



At any given time, climate is largely controlled by the energy of the

sun and the earth's position relative to the sun.



The amount of carbon dioxide added to the atmosphere by human

activities (2 percent of 0.03 percent, which is 0.000006 percent)

when compared to water that is always present (range of 0.5 percent

to 4 percent) is a very small amount.



Pound-for-pound, water absorbs two times more heat energy than carbon

dioxide.

Too often, experts, and even scientists study and report the effects

of CO2 on climate in a manner that is similar to the story of five

blind men describing an elephant. Each one views the elephant as a

completely different being because he doesn't include the information

from any of the others.



The situations with studies or reports on global warming are similar.

Unless we consider all of the factors that contribute to our climate

simultaneously, we are using an unscientific technique known as data

selection, which is inappropriate in thorough and accurate research.



By evaluating changes in climate or temperature over shortened

periods, such as decades or centuries instead of hundreds of

thousands or even millions of years, we either overestimate or

overstate the changes that might or might not be occurring. Data

selection can be used to verify any reasonable conclusion about

climate change.



Because there is a lot more water in the atmosphere than carbon

dioxide and because water absorbs so much more energy than carbon

dioxide, we should conclude that the effect that these gases have on

the warming of the atmosphere is largely caused by water. Man's

contribution, although it certainly exists, is more like throwing a

stone into the ocean, real and calculable, but barely noticeable.



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G.W. Burrows is a retired analytical chemist and former director of

toxicology and environmental chemistry laboratories. Burrows

currently teaches chemistry, biology and environmental science.



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