Galileo would be smiling

The climate debate

  • A lethal phrase about a highly contentious issue is that “the science is settled”. Climate change is one such subject. There is an ever expanding literature claiming that human activity, and especially the presence of carbon dioxide (CO2), is responsible for global warming. Galileo must have felt like today’s climate deniers, when he asserted that the earth rotated around the sun thereby contradicting the religious experts. Although eventually proven right, Galileo had to appear before the Inquisition whose membership of learned clerics held the opposing view that the sun circled the earth. In the end the clerics were found out to be charlatans. (The film The Name of the Rose, and in a lighter vein a Monty Python skit, illustrate how the Inquisition worked in a less than politically correct manner.) My colleague Michael Hart explains this and much more in Hubris: The Troubling Science, Economics, and Politics of Climate Change.


  • I enter this debate with no background in climate research, having written nothing on the subject except a blog posting on Dec 8, 2014 ( But after a half century in academia, I do have some ability for detecting bullshit, how it gains financial backing and then becomes considered a financial entitlement.


  • The essence of the global warming argument goes something like this. The temperature of the earth varies over time, by the hour, season and era, either rising or falling. In the past few decades it has been stable, but in the last decades of the twentieth century, it rose by perhaps as much as half a degree. Human related activity is thought mainly responsible by causing increased CO2 in the atmosphere. The consequences are bad if not catastrophic for humanity, and thus the need to introduce policies to prevent the rise. So goes the argument.


  • This doctrine has a large following around the world, and those who think otherwise are viewed as heretics. Elected politicians dare say nothing critical for fear of offending true believers, while pouring forth policies to support it. A recent example is the Ontario government’s Five Year Climate Change Action Plan, 2016 – 2020 – see (  There are many others in the bible of climate change.


  • (As an aside, less than flattering commentary is made about how Ontario has dealt with similar policies to-date.  “ The Liberal Government brought in the Green Energy Act and signed multibillion-dollar deals with manufacturers of solar- and wind-power parts and were very proud of it, and then they watered down parts of the law and carved billions of dollars off the manufacturing deals and are very proud of that too. They pushed for offshore wind farms and then scrapped them, and now we’re being sued for a billion dollars. They brought in variable pricing for electricity to make it more expensive to use when it’s more expensive to generate, but didn’t make the difference sharp enough to make a really big difference. Wynne (the Ontario Premier) herself promised an adult conversation about raising money to pay for a giant transit construction program, then backed away from all the(Ottawa  hardest ideas like increasing sales and gasoline taxes. Nobody’s built a new toll road either. (Ottawa Citizen, June 9, 2016, A7).


  • Similar behaviour took place when the Limits To Growth hypothesis was proposed in 1972, and later found to be wanting.”The original version presented a model based on five variables: world population, industrialisation, pollution, food production and resources depletion. These variables are considered to grow exponentially, while the ability of technology to increase resources availability is only. The authors intended to explore the possibility of a sustainable feedback pattern that would be achieved by altering growth trends among the five variables under three scenarios. They noted that their projections for the values of the variables in each scenario were predictions “only in the most limited sense of the word,” and were only indications of the system’s behavioral tendencies. Two of the scenarios saw “overshoot and collapse” of the global system by the mid to latter part of the 21st century, while a third scenario resulted in a “stabilized world.”


  • The science is settled was the cry of the “Limits To Growthers”. It turned out differently in many ways. For example, today the planet is awash with oil and natural gas. But examining this earlier religious belief, which turned out to be flawed, is for another time. For those interested, Wikipedia, source of the above quote, provides a summary account of what happened and why some still claim its validity while others disagree. A scientific approach is to state a hypothesis and then collect facts to support and refute it.


  • How might science be able to help regarding the present climate change debate?  “The science is settled” mantra reflects a misunderstanding of what is generally considered to be scientific methodology.  It involves stating a relationship which can be tested against available facts and information. The information is either supportive of or contradictory to the proposed hypothesis. Those wanting to support a hypothesis should search diligently for information which will reject it. If they find none, then they have not settled the issue, but they have reason to believe in it until conflicting information is found. Science is never settled as Galileo’s opponents found…..maybe one day we will find Galileo was wrong but at present most support his view.


  • What scientific inquiry aims to establish is whether global warming is taking place, whether carbon dioxide is increasing due to increased human activity and whether this is the cause of global warming today. By testing these hypotheses it will be possible to say that available evidence supports or rejects the relationships. It will never be possible to say that the science is settled, because it never is about any hypothesis. Religious beliefs can be settled for believers, but not scientific knowledge for scientists and those using their research. If you, the reader, know the science is settled, then there is no need to read any further. You are a believer not a scientist, and you will join a large band of believers, who unfortunately, in my view, are driving the debate for policy change.


  • How do you measure the temperature of a planet consisting of land and water, of places with different latitudes and longitudes, of seasons that vary from hot to cold, and of land areas and oceans with different altitudes and depths? These are only some of the variables that may affect how the temperature of planet Earth is determined.


  • There seems to be general agreement that the temperature of the planet changes over time, and that at present it is experiencing a warming trend from an earlier ice-age some centuries ago. There is also agreement that the population of the planet has increased from around 2.5 billion in 1950 to over 7 billion today, heading towards 10 billion by 2050 before it starts to taper off. Finally there is agreement that the amount of CO2 in the atmosphere is caused by a combination of factors, one of which results from human activity. There is no agreement that the increase in CO2 today is primarily due to human activity as opposed to the other factors which cause changes in the level of this gas.


  • In the past there have been periods when the amount of CO2 in the atmosphere increased but global warming was not observed. Something else was the cause of global warming. This should at least give pause to the views of some believers.

Finally, a modest suggestion to the Canadian Environment Minister,that she appoint at least one advisor who has  a scientific frame of mind and is willing to go beyond the “science is settled” mantra. It is not the number of people who take a particular position but the quality of their case that matters.The proposal here is for an adult conversation about these important issues.


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