You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
There are misconceptions about climate change and several are based on half-truths and misleading arguments, rather than solid science, says Doug Mackie who takes issue with the sceptics.
It is not true that arguments presented with equal force have equal validity.
It may be so in some of the more nebulous social sciences . . . but it is not so in the physical sciences.
THOSE of you who wasted your youth in video game arcades will have seen that one of the more popular games isn't a video game at all - it is a clanking and grinding machine.
The Whac-a-Mole game has a waist-high box with several holes.
Mechanical moles pop out and have to be whacked with a large mallet to score points.
It sounds kind of dumb but it can be quite therapeutic.
Not so with climate-change sceptics.
No matter how many times a specious argument is whacked down, up pop other claims (witness Geoffrey Kearsley's article "Climate change debate is being distorted by dogma", Otago Daily Times, 17.7.08) that have been proven wrong many times before.
Before I start any research and whenever I read a scientific claim, I check what has been published in the journals.
One expects academics to carry out this sort of research as a matter of routine.
Occasionally, one strays from one's area of expertise and rather than assess the literature and learn all the jargon it is tempting to see what Wikipedia or some random blog says.
There are three problems with doing that:First, if truth and accuracy were the sole criterion for posting then the entire content of the world wide web could probably fit on a single DVD.
Second, it is not true that arguments presented with equal force have equal validity.
It may be so in some of the more nebulous social sciences that there is no right answer, but it is not so in the physical sciences.
Physics doesn't argue if an apple will fall or not. Physics tells you how fast the apple will fall.
You don't have to be a physicist to know that a website selling a device to neutralise gravity is dodgy.
Third, not to refer to the primary literature, especially if it is a large and mature field of research, in my opinion shows research skills below what one might expect.
Rather than embark on a paragraph-by-paragraph rebuttal of Prof Kearsley's opinion piece, I want to bring up two points.
Consider the claim that the Al Gore film An Inconvenient Truth has "been shown to be riddled with inaccuracies, distortions and misrepresentations".
As I did in a letter to this paper in February, I yet again point out the judge's actual statement was that the film is "broadly accurate" - http://www.bailii.org/ew/cases/EWHC/Admin/2007/2288.html.
Consider the claim: "In the 1970s, climate science was concerned about when the next ice age might commence".
Even a cursory look at the primary literature gives the lie to this.
USA Today is hardly a broadsheet (physically or intellectually) but got it right in February this year when it summarised a journal article that showed this idea had never been the consensus. See http://www.usatoday.com/weather/climate/globalwarming/2008-02-20-global-...
It is "broadly accurate" to define science as that which is testable. If a claim can't be tested in some way then it isn't scientific.
For example, the great geneticist J. B. S. Haldane was asked what he would consider as evidence against evolution and he replied "fossil rabbits in the Precambrian".
Evolutionary theory is that there were no land animals of any sort, let alone rabbits, during the Precambrian, which lasted from the formation of the Earth to about 540 million years ago.
Indeed, the next geological period - the Cambrian - is defined by the first appearance of numerous multicellular fossils (slimy things that crawled with legs upon a slimy sea).
So to find such fossil rabbits (or fossils of any vertebrate) would immediately prove the theory wrong.
I have a "fossil rabbit" of my own regarding climate change.
That is, I can identify a situation where I can be proved wrong about climate change.
One of the least well known but very serious threats from climate change is the incontrovertible fact that the oceans are acidifying.
I stake my belief in climate change on there being only one plausible explanation for this acidification.
We know with reasonable accuracy how much CO2 is being released by fossil-fuel burning.
We know by how much CO2 in the atmosphere is increasing.
We know that the two values do not match - about half the CO2 is missing from the atmosphere.
We suspect that the CO2 has dissolved in the oceans, making a sort of "soda-water".
We know that if the acidification trend continues many organisms will not be able to grow their shells.
It seems a curious coincidence that the amount by which the ocean has acidified corresponds exactly with the amount of missing CO2.
If there is an explanation for the acidification that doesn't involve the missing CO2, it will prove me wrong.
I challenge sceptics to tell us their fossil rabbits.
If they can't be proved wrong then they aren't using science.
Dr Doug Mackie is a research fellow in the department of chemistry at the University of Otago.
He is the author, with Prof Keith Hunter, of Climate Change Mythconceptions: Some Incorrect, Irrelevant and Misleading Arguments Made by Climate Change Denialists, published in the New Zealand Institute of Chemistry magazine: http://www.nzic.org.nz/CiNZ/CiNZ.html
Climate change "myths"
• Water vapour is the dominant greenhouse gas.
The water content of the atmosphere responds to temperature whereas CO2 causes the temperature change.
• Britain is 1degC cooler now than it was at the time of the Domesday book.
In most places temperatures are rising but these very changes alter heat circulation. Temperatures in Britain are only secondarily related to global temperatures, due to the effect of the Gulf Stream.
• Global warming stopped in 1998.
1998 was hotter than the years before and after because of a change between a strong el Nino to a strong la Nina. But the general trend over the past 200 years is steadily up.
A brief dip in the 1950s was due to increased particulate pollution.
• The CO2 has come from the oceans.
Isotope ratios show this has not happened.
Most of the CO2 is in the deep ocean. If deep ocean water had come to the surface it would have caused other effects and been noticed.
• Sunspots are to blame.
It is true solar energy output cycles in step with sunspot activity. But the cycle is smoothly up and down.
There has been no change in solar output to explain the increased temperatures on Earth in the past few decades.
• Further reading: Probably the best resource in existence is the website www.realclimate.org. More myths are covered in lay terms at http://environment.newscientist.com/channel/earth/dn11462 and http://gristmill.grist.org/skeptics.