On November 5, 2023, Leslie MacMillan wrote a comment on Patrick Hunt’s guest post, of the same date, here. Leslie’s comment is set out under the first heading, below. Because his comment raises important issues I thought it would be desirable to respond to them in a new blog post, under the second heading, below. Leslie can always reply after this is posted, so he can have the last word.

Leslie MacMillan’s Comment

Patrick, your post seems to make two arguments. 1) That CO2 does not cause global warming — “The Climate is Always Changing” –and 2) That efforts to reduce CO2 emissions will impoverish us. Only the second argument is necessary and compelling.

All your arguments under 1) were refuted many years ago as being either false or, more subtly, irrelevant to modern human time scales. Geologic time is almost unimaginably longer than the duration of human civilization. Coal was formed 300 million years ago, which is 30 thousand times as long as agriculture has existed. Not industrial coal burning, all of civilization. What you are doing is confusing very long term changes in estimates of global mean temperature and atmospheric CO2 with the much shorter time scales that are relevant for humans today. It is indeed relevant what this relationship looks like over the past 100-200 years. What it looked like between 600,000 years ago and 500,000 years ago just doesn’t matter. (In any given century 600,000 years ago we might well have seen a closer correlation between temp and CO2 if we could somehow measure it that precisely, except that at no time in geological history (so far as we can tell) has atmospheric CO2 risen as rapidly, per decade, as it is doing today.

That said, Argument 2) should be where you concentrate your efforts. There is no need to try (and fail) to debunk the central tenet of climate science, that CO2 is a greenhouse gas with possibly important effects in modern times at century scales. The consequences of trying to fix it will be ruinous. Rising interest rates, the reality check of technology not developing as fast as it “needs” to, and the clear policy of China and the rest of Asia to abandon the game, are causing many countries (except Canada and the U.S.) to backtrack from their ambitious Gross-Zero plans. (And cracks are appearing in the carbon tax, the Crown Jewel of Canada’s climate plan.)

The message is that climate change is a collective action problem. Like all CAPs, it becomes intractable for all once one powerful actor decides to abandon the commitment to collective action. It then doesn’t matter whether anybody else cooperates like good Boy Scouts because the defector will profit off the misfortunes of the cooperator. Under those conditions, the usual admonition about, say, littering or ordinary common courtesy on the roads — One person can’t do much but he can do something and be a good moral example — simply doesn’t hold.

As you recommend, we should concentrate on adaptation, not try to “fix” the climate. And that requires economic prosperity to do.

Reply to Leslie MacMillan

Hello Leslie,

This is a joint reply to your comment from Patrick and me. 

The reason Western countries are making heroic efforts to eliminate CO2 emissions, while most others countries are not, is based on a perceived moral duty: to do our part save the planet from catastrophic climate change.  To argue only that Western countries are using the wrong methods, without responding to the the moral argument that “we” must fight the “climate crisis” would imply that we don’t care about the predicted severe impacts of the “climate crisis”. This crisis is widely described as potentially causing millions of deaths, if not another great extinction.  That’s why it’s necessary to discuss both: whether there is a climate crisis that will cause the planet to “boil” (to quote UN Secretary General Antonio Guterres), and if so, to discuss the proposed solutions.  However, if there is no human caused climate crisis that we, collectively, need to solve or can solve, then any proposed solution is irrelevant, extremely costly, and positively harmful.

We respectfully disagree that “All your arguments under 1) (rate of and cause of global warming) were refuted many years ago or are irrelevant under human timescales.”  They have been disagreed with, but not refuted. The laws of physics, particularly astrophysics, are unrelated to and do not vary with, human timescales.  And mathematical models about the rate and cause of future global temperature changes are merely hypothetical “if…then…” statements. They are opinions about the future, expressed in equations rather than verbal language. The opinions of model makers will differ, but their models can’t “refute” anything. The future, particularly as far ahead as 2050, hasn’t happened yet.

Dr. John Christy of the University of Alabama, Huntsville, has compared the climate models commonly used today to actual, observed temperatures over the last 40 years that satellites have been able to record accurately.  One of his many presentations can be found at: Clintel

As Christy shows, the IPCC models, on which many national climate policies are based, are running on average four times hotter than actual, observed temperatures over the last 40 years.  These models, with their rapidly rising temperature curves, predict the future to be at least four times hotter than current trends would indicate.  They also fail to consider that current trends may reverse, as has often happened in the past.

The climate is a non-linear, chaotic system.  No reputable scientist would argue that the science is settled.  During the Little Ice Age, between  1600 and 1814, the Thames River regularly froze over, so that people could hold “Frost Fairs” with food and drink, and also skate on it. In the Great Winter of 1683/84, even the seas of southern Britain were frozen solid for up to two miles from shore. Because this cold temperature caused famine and death there were those who argued that this climate change was man-made, or at least witch made, as demonstrated in this bit of history from: Witch Hunts and Climate Change.

The medieval belief that evil humans were negatively affecting the climate has been revived in the current claim that human actions are controlling the climate and leading to a global catastrophe.  Anthropogenic CO2 has replaced the witches.

Yet CO2 hardly changed at all during the Little Ice Age, staying around 280 PPM + 5 PPM until around 1800, as  Steve McIntyre shows in the blue line in the next graph. (The red line in this graph also shows the famous Michael Mann temperature “hockey stick”, rapidly rising after around 1850):

(As an aside, Mann’s red line takes away the Medieval Warm Period as well as the Little ice Age, to make it appear as though temperature was as flat as CO2 until the 1850’s, when both rose exponentially. This trick was exposed by Ross McKitrick and Steve McIntyre, which led to the “Climategate” scandal.)

So, what caused the rapid and prolonged global cooling during the Little Ice Age, while the atmospheric concentration of CO2 remained stable?  Instead of pretending we know the answer, and blaming it all on CO2, we would offer no comprehensive climate change theory beyond saying that it is complex, with many unknowns.   That is better than offering a theory that is clearly wrong.  Then, as you suggested, let’s adapt to whatever the climate decides to do, as it has done in the past. 

However, if the sun spot cycles continue as observed over the last 400 years, we could experience colder weather, not warmer weather, starting in the next 30 years.  We are not alone in recognizing this possibility. For example, Russian astrophysicist Habibullo Abdussamatov and his colleagues believe that global warming and cooling are primarily caused by natural processes over which humans have no effective control.  He is a responsible, senior scientist: the supervisor of the Astrometria project of the Russian section of the International Space Station, and also, the head of the Space Research Laboratory at the Saint Petersburg-based Pulkovo Observatory of the Russian Academy of Sciences.

In 2012, Abdussamatov (again) predicted the onset of a new “mini-ice age” starting around 2014 and becoming most severe around 2055.  Abdussamatov quantified a declining trend in Total Solar Irradiance and predicted further cooling, around 2055, to be caused by that declining trend. If the scientists at the Pulkovo Observatory are right the trillions being spent by some countries on net zero, and the economic hardship that that is creating, will accomplish nothing to protect us from the coming global cooling cycle. Meanwhile, China, which is building hundreds of new coal plants, will be toasty warm and very prosperous.  There are many better ways for Canada (and other Western countries) to spend these enormous sums of money than chasing net zero, such as reducing the huge national debt, improving medicare and surgical wait times, and enhancing social assistance payments.