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Ian Plimer

Occam’s Razor*

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For more than 80% of time, Earth has been an iceless, warm, wet, greenhouse planet. Past temperate changes have been far greater and far more rapid than anything measured in modern times. We humans have adapted to live on ice, mountains, in the tropics, in deserts and at sea level.

Past great climate changes were driven by natural cyclical processes such as the position of our Solar System in the Universe, wobbles in the Earth’s orbit, changes in the Sun, oscillations in the oceans and tidal changes. Random events, such as volcanoes, also changed climate. In the past climate has not been driven by atmospheric carbon dioxide and water vapour is the main greenhouse gas.

The greatest biomass on Earth has always been bacteria and bacteria are the only life on Earth that has ever made great changes to the atmosphere. Since the first photosynthetic bacteria on Earth more than 2,500 million years ago, life has been sequestering carbon dioxide.

Over the last 500 million years, carbon dioxide from the atmosphere has been sequestered into algal and coral reefs, shells, cements, precipitates, fossil fuels and sediments. During these times of very high atmospheric carbon dioxide, the oceans were not acid. As a result, the atmospheric carbon dioxide has been decreasing over time despite massive additions from natural processes.

To state in public that carbon dioxide is a pollutant is a public advertisement of a lack of basic school child science. Pollution kills, carbon dioxide leads to the thriving of life on Earth and increased biodiversity. Carbon dioxide is plant food.

There have been six major ice ages.Two of these show that there was ice at sea level at the equator and five of these occurred when the carbon dioxide content of the atmosphere was up to 1,000 times greater than now.

The proposition that a high atmospheric carbon dioxide content creates global warming, tipping points and unstoppable global warming is incommensurate with the past. In a past great ice age, an interglacial sea level rise of at least 600 metres was associated with a sea surface temperature rise to at least 40ºC. Now that’s a climate change.

There has been global cooling for the last 50 million years. Because South America separated from Antarctica some 37 million years ago, the circum-polar current resulted in the isolation of Antarctica and the development of an ice sheet. Despite numerous long events when it was far warmer than at present, the Antarctic ice sheet did not melt.

It was only after two coincidental events 2.67 million years ago, the joining of the Americas and a supernoval eruption, that polar ice appeared in the Northern Hemisphere. These polar ice sheets waxed and waned, as they do now. Ice core studies show that after a cyclical temperature increase, the atmospheric carbon dioxide content increased some 800 years later, again showing a disconnect between atmospheric temperature and carbon dioxide.

During the last great interglacial some 125,000 years ago, sea level was 7 metres higher than at present and atmospheric temperature was some 5ºC warmer. We are now in an interglacial.

The ice sheets did not completely melt and humans thrived. During the latest glaciation, the Toba supervolcano eruption 74,000 years ago led to intense cooling. Humans very nearly became extinct.

The zenith of the last glaciation was 18,000 years ago. During the current interglacial, sea level has risen 130 metres in 14,000 years, a rate far higher than the most exaggerated model for human-induced global warming.

During the current interglacial, there were a number of exceptionally cold snaps and temperature rose by as much as 20ºC in 15 years after one of these periods. There were also alternating cool windy dry times and warm wet times. Some 6,000 years ago sea level was 2 metres higher than at present and it was at least 3ºC warmer than now.

Cool times led to desertification and the collapse of great civilisations and warm times led to the thriving of humans. The temperature and rate of temperature change in the Minoan, Roman and Medieval Warmings were greater than today.

In the Roman Warming, grapes and citrus were grown as far north as Hadrian’s Wall. The Roman Warming came to a sudden end in the middle of the sixth Century AD due to a coincidence of solar, extraterrestrial and volcanic activities.

Atmospheric aerosols from these volcanoes and cometary dust resulted in cooling, acid rain, crop failures, famine, attacks on the weakened population by the plague, changes of empires and depopulation.

The Medieval Warming commenced with a very active Sun. Between 900 and 1300 AD, it was warmer, times were prosperous and generational wealth was used to build the great cathedrals, monasteries and universities of Europe. The Vikings colonised Newfoundland and called it Vinland. No grapes could survive the cool climate of Newfoundland today.

In the Medieval Warming, wheat, barley, sheep and cattle were grown in Greenland in places now covered by ice. Atmospheric temperature was at least 5ºC warmer than at present.

A solar change in 1280 AD led to the Little Ice Age. It took 23 years to change from the Medieval Warming to the Little Ice Age. There was crop failure, starvation and murderous climate refugees roamed Europe. The stressed population succumbed to the plague and there was massive depopulation.

During times of decreased sunspot activity, it was far colder, there was civil unrest, starvation, ice-fairs on rivers and increased cloudiness.

The Little Ice Age ended about 1850. Since then, Earth has warmed at the same rate from 1860-1880, 1910-1940 and 1975-1998. Atmospheric temperature has been decreasing in the 21st Century despite an increase in atmospheric carbon dioxide.

The climate models show that temperature should have been increasing in the 21st Century. This disconnect again shows that carbon dioxide does not drive temperature and that models of very complex chaotic natural systems should be viewed with great caution.

Despite the 21st Century decrease in global temperature, we are perpetually warned of dangerous global warming. The proposition that climate should not change is absurd. This can only be promoted if all history, archaeology, geology, astronomy and solar physics are ignored – yet these are ignored in climate models. In effect, we are suffering climate wars with one group heroically using incomplete computer models to make predictions and another group using natural science.

If an extraordinary claim is made, then extraordinary evidence must be given in support. This has not been done.

Those who argue that human emissions of carbon dioxide change climate must demonstrate that changes observed today are not natural. This has not been done.

If such warmings and coolings took place in the historical past before industrialisation, why is the most recent warming now due to human activity? Past natural changes are far greater than any changes measured in the 20th and 21st Century yet modern natural climate changes are touted as dangerous climate change.

Both the sea and the land rise and fall and it is extraordinarily difficult to measure current sea level changes and much easier to measure past changes. Scandinavia was covered by 5 km of ice which started to melt 14,000 years ago. As a result, Scandinavia rebounded and has risen by up to 340 metres.

The Roman Port of Efeses is now 15 km inland and 7 metres above sea level and the ancient city of Lydia is now some 4 metres below sea level.

Tuvulu is located where the floor of the Pacific Ocean is subsiding and relative sea level at the Maldives has fallen 20 cm since the 1970s. The tidal measuring station at Port Adelaide shows a relative sea level rise of 2.4 cm per year as a result of sinking of the measuring station.

The planet’s ice sheets are dynamic. Beneath the Antarctic ice sheet are active volcanoes with associated high temperature gas vents and hot springs. The last great eruptions were in Roman times. Records of mountain glaciers in Europe show multiple events of ice advance and retreat over the last 4,000 years.

Great state broadcasting and research institutions, some professional societies and academies and many university institutes have now become totally politicized. Dispassionate independent fearless advice from government departments now no longer seems possible.

I never thought I would see the day when the only balance on a matter of science derives from commercial radio. Major capital city newspapers promote a doom-and-gloom scenario and The Australian valiantly tries to present a diversity of opinions.

Polemical criticism of my book Heaven and Earth has been savage because there are a large number of career climate comrades who frighten us witless about climate change and who would be unemployable outside taxpayer-funded climate institutes.

The total politicisation of science, as demonstrated by the use of consensus and the science is settled, has been easy because of the dumbing down of the education system, the lack of critical and analytical thinking and instant information, most of which is unvalidated. No scientific breakthrough has ever been made by consensus.

Political decisions regarding emissions trading have had neither scientific nor financial due diligence. The major source of information derives from a political body, the IPCC, and some climate centres, such as the Hadley Centre, even refuse to release taxpayer-funded primary data for re-evaluation.

The global warming movement has not shown that emissions trading legislation will do anything to change the global climate and has opened up opportunity for unregulated opaque trading across jurisdictional boundaries. Such trading will create huge bureaucracies and will make a fortune for bankers, brokers, traders and governments.

These are the same folk who brought us toxic derivatives and now want to impose a guilt tax on the very substance that allows life on Earth. Climate change consensus is reinforced by commercial interests, constant repetition of the mantra, research grants, subsidies, politicians looking for votes, international travel to vital Earth-changing conferences, proliferation of costly reports and investigations with predetermined conclusions, fame and fortune for scientists and journalists seeking headlines warning of an impending catastrophe, clamorous demonstrations and preaching of unchallenged gospel by those with an undeclared self interest.

This movement has the elements of failed European socialism and religion, imposes guilt on the community, creates a fear of damnation, demands appeasement by selling indulgences to the faithful, ignores any contrary information, demonizes dissenters, has a holy book which adherents have neither read nor have the knowledge to understand, breed gurus whose mantras can not be challenged and make sensationalist claims.

The most dangerous aspect of this new fundamentalism is that it ignores history and has hints of totalitarianism. It cannot answer simple questions.

  • What is the right temperature for the Earth?
  • What is the right carbon dioxide content of the atmosphere?
  • Why should enormous economic pain be imposed?
  • Why is carbon dioxide increasing yet temperature is decreasing?
  • Why have climate models not been run backwards to replicate what we know?
  • Why have major Earth processes been omitted from models?
  • Why is scientific dissent demonised?

Science is married to integrated interdisciplinary evidence and is not a tool for government games of fear and taxation.

No civilisation has ever been saved by a new tax.

* Editors note: Occam’s razor is the idea that, in trying to understand something, getting unnecessary information out of the way is the fastest way to the truth or to the best explanation. The theory was developed by William of Ockham (1285-1349), an English theologian and philosopher. One consequence of this methodology is the idea that the simplest or most obvious explanation of several competing ones is the one that should be preferred until it is proven wrong.