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Myth versus facts

Jun 26 2013 16:48
*Geoffrey Chapman


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Climate change and you

“FOR the greatest enemy of truth is very often not the lie - deliberate, contrived and dishonest - but the myth - persistent, persuasive, and unrealistic.

"Too often we hold fast to the clichés of our forebears. We subject all facts to a prefabricated set of interpretations. We enjoy the comfort of opinion without the discomfort of thought.” - John F Kennedy, Yale University commencement address (June 11, 1962).

The idea of National Treasury proposing a carbon tax has caught my attention for a few reasons. Firstly, there is a debate around the man-made contributions of CO2 versus natural contributions. Secondly, the debate about whether or not global temperatures are rising.

Lastly, climate scientists cannot conduct a controlled experiment; climate scientists cannot control nor manipulate the entire Earth nor compare it to an alternative and identical planet - so how do we know for sure humans are the cause of climate change?

Consequently, I will attempt to debunk the myths a little bit, to allow you to think and form an opinion based on facts.

Humans are contributing excessive amounts of CO2

The Intergovernmental Panel on Climate Change reports that humans contribute 29 gigatons of CO2, whereas 770 gigatons of CO2 is contributed by the oceans, vegetation and land. Looking at 29 gigatons against 770, that is less than 4%.

The proponents of reducing carbon emissions will say that we have upset the balance of nature, and that we are breaking the camel’s back because the Earth’s carbon reservoirs naturally act as both sources, adding carbon to the atmosphere and sinks (areas that naturally absorb carbon, such as forests), removing carbon from the atmosphere.

There are thus two sides to this story: on the one hand, humans are emitting carbon and on the other, we are the cause of deforestation, exacerbating the situation at both ends.

From this, the proponents will state that this is leading to rising temperatures. The media itself focuses on “rising global temperatures”. Even the United Nations executive summary on climate change, issued in January 2001, insists that the 20th century was the warmest in the last millennium.

But is this true?

Global temperatures are rising

Climate change is controlled primarily by cyclical eccentricities in the Earth's rotation and orbit, as well as variations in the sun's energy output. "Greenhouse gases" in Earth's atmosphere also influence Earth's temperature but to a much smaller degree.

Human additions to total greenhouse gases play a still smaller role, contributing about 0.2% - 0.3% to Earth's greenhouse effect (which is a natural phenomenon by the way) and carbon dioxide does not trap heat as effectively as other greenhouse gases (making it a less potent greenhouse gas).

There are three major causes of global temperature shifts:

1. Astronomical causes

a. Cycles of solar variability – an 11- and 206-year cycle,
b. Earth's combined tilt and elliptical orbit around the sun (precession of the equinoxes) – a 21 000-year cycle,
c. Cycle of the +/- 1.5° wobble in Earth's orbit (tilt) – a 41 000-year cycle, and
d.  Variations in the shape of Earth's elliptical orbit – a 100 000-year cycle.

2. Atmospheric causes

a. Heat retention: due to atmospheric gases, mostly gaseous water vapour (not droplets) and gases such as carbon dioxide, methane and a few others – the "greenhouse effect", and
b. Solar reflectivity: due to white clouds, volcanic dust and polar ice caps.

3. Tectonic causes

a. Landmass distribution: shifting continents (continental drift) causing changes in circulatory patterns of ocean currents. It seems that whenever there is a large land mass at one of the Earth's poles, either the north pole or south pole, there are ice ages.
b. Undersea ridge activity: "sea floor spreading" (associated with continental drift) causing variations in ocean displacement.

Global climate and temperature cycles are the result of a complex interplay between the causes mentioned above and because these cycles and events overlap, they can either compound or cancel one another out.

As most climatologists know, the reports of rising temperatures are generally founded on ground-based temperature readings, which are misleading.

The more meaningful and precise orbiting satellite data (accurate to within 0.1° C ) for the same period (which are generally not cited by the media) have year after year showed little or no warming over the last 18 years for which they have continuously been recording temperatures.

The idea that man-made pollution is responsible for global warming is not supported by historical fact. The period known as the Holocene Maximum is a good example – so named because it was the hottest period in human history.

The interesting thing is this period occurred approximately 7 500 to 4 000 years ago - long before humans invented industrial pollution.

The atmosphere has seen rising levels of CO2 for the last 18 000 years, long before industrialisation and so, evidently, man played no role in the pre-industrial increases.

Concomitantly, temperatures have been increasing for the same period but interestingly, CO2 lags an average of about 800 years behind the temperature changes – confirming that CO2 is not a primary driver of the temperature changes.

Incidentally, Earth's temperature and CO2 levels today have reached levels similar to a previous interglacial cycle that occurred between 120 000 and 140 000 years ago, a period known as the Eemian Interglacial Period. From beginning to end, this cycle lasted about 20 000 years and immediately after, Earth returned to a full-fledged ice age.

Thus, if there is no definitive proof that global temperatures are rising, are we breaking the camel’s back? Are humans upsetting the scale?

One last point of interest before I summarise: water vapour is the most significant greenhouse gas (95% of the greenhouse effect) and it comes from natural sources (only 0.001% is from man-made sources).

Let’s recap: humans are contributing between 0.2% - 0.3% of all greenhouse gases, which in their entirety contribute much less to global temperatures than the three primary causes (astronomical, atmospheric and tectonic).

Carbon in the atmosphere may be increasing, but this is a trend that started 18 000 years ago – humans are not the cause and we are not upsetting the balance. Further, even if temperatures are increasing incrementally, this is due to the Earth’s natural phases and is not the result of rising carbon emissions.

Is a carbon tax justifiable?

I suppose it depends on the motivation for the tax. If the motivation is to curb climate change, then I do not think National Treasury has any grounds to stand on.

If the aim is to generate tax revenue, then it will certainly achieve its goal because South Africa is a carbon-intensive economy with some of our biggest employers (mining, energy and manufacturing) being the country’s highest carbon emitters.

But what will the consequences be on implementing another tax on a country that is battling to cope as is, for the sole purpose of generating tax revenue?

 - Fin24

*Geoffrey Chapman is a guest columnist and trade policy expert at the SABS. Views expressed are his own.

geoffrey chapman  |  global warming


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