Climate science: The issues in brief

We've covered the science behind climate and energy policies, although it is admittedly a heavy read. For those who prefer a more concise format, this is a shortlist of the issues uncovered in climate change theory and its promoted solution, renewables.

The warming effect of CO2 for various concentrationsThe point about all this is that no one single questionable item renders the climate change theory invalid. However, when a wealth of questionable items exist across many aspects of the science, then with every additional questionable item the credibility of the science -and the political argument for following certain policies- becomes ever weaker. 

With any branch of science or engineering, an important process in validation of findings is the raising of objections to the proposed theories by peers. This raising of objections  is an important part of the scientific process, since it should, if the aims of the scientists are genuine, help them to weed out errors in their work.

So, here I present a list of the issues which I see with the science and engineering. This should be taken as constructive in nature, since if climate scientists and renewables vendors can answer them satisfactorily it will greatly improve the authenticity of their claims.

The principal claims

The argument goes that carbon dioxide is a greenhouse gas, and that human activities are increasing the levels in the atmosphere quite considerably. This, it is claimed, will lead to runaway, irreversible changes in the Earth's climate.

The remedy offered is the mass replacement of fossil fuel energy with renewables. It is claimed that renewable energy is a wholly viable replacement for fossil fuels, and that it may even turn out to be a cheaper alternative to oil, coal or gas.

Thus we have a problem and a proposed solution. Two questions arise here:

  1. Is the problem genuine?
  2. Assuming it is, will the proposed solution work?

Part1: Climate Change


The problems with the 'enhanced greenhouse' theory

Greenhouse effect is inherently self-limiting, not self-enhancing

Most of CO2's effect occurs at very low concentrations The greenhouse effect of CO2 has been well understood for over a century. The effect of all greenhouse gases is logarithmic. That is, the larger the amount present, the less effect any further increase will have. A law of diminishing returns, in other words.

Most of CO2's greenhouse effect is already present by 40ppm, or a tenth of present levels. Further increases have a proportionately smaller effect. The change from 270 ppm to 400ppm over the industrial era should, in theory, have resulted in 1.7 Celsius of warming. In fact, the figure is more like 1.3C.

The science says that still further increases beyond the present level will have proportionately less effect. Not greater effects, as some activists have claimed.

This very fact makes runaway effects unlikely. It results in a system which is inherently self-stabilising. Thus, even if CO2 is the predominant greenhouse gas, increasing its level still further than the present 400ppm moderately, or even quite considerably,  is not likely to have catastrophic effects.

Observe the graph below, which was produced by the official greenhouse effect calculator MODTRAN, and ask yourself if you think it's likely that the change in the amount of infrared getting through the atmosphere from pre-industrial 270ppm to a present day 400ppm of CO2 is likely to have even noticeable effects, let alone catastrophic ones.

Comparative MODTRAN infrared spectra for pre-industrial era and present dayAdditionally, we have to consider that CO2 is not the only greenhouse gas. Where two greenhouse gases share the same infrared absorbtion band, the effect will NOT be the sum of the individual effects. Rather, the stronger greenhouse gas will absorb the majority of the energy, leaving the weaker with little or no function. 

Water vapour is by far and away more abundant in the atmosphere than CO2. If you examine water vapour's  infrared spectrum you will see that it is much broader than that of CO2, and importantly, it covers most of CO2's absorbtion band. This explains why the warming effect of added CO2 is much less than even the moderate amount that theory would predict.

Water vapour is the predominant greenhouse gas. CO2 is an 'also ran' alongside its effects.

Just go outside on a cloudy night, and note that it is not significantly colder than during the day. Go outside on a clear night and you might need a coat even though you were sunbathing in shorts that very day. When there is water vapour in abundance, there is strong greenhouse effect and the lower atmosphere stays warm. When there is not, the puny effect of carbon dioxide is no substitute for it.. and  you shiver.   


A claim of the activists is that although the effect of CO2 is small, it will be amplified to dangerous proportions by 'feedbacks' in  the climate system. Some say that these feedbacks will take us over 'tipping points' beyond which the climate will go out of control. More on this later.

First, let's think about the feedback idea. One suggested feedback is water vapour being released from the oceans as the planet warms. It has been suggested that this water vapour, being itself a greenhouse gas, could 'amplify' the admittedly small effect of CO2. It is claimed that this 'feedback' could give a gain in the region of three to five.

There are two problems with this idea. Firstly, as any electronics engineer will tell you, it is extraordinarily hard to produce a stable amount of gain from a circuit using positive feedback. More often, positive feedback will just cause the system to break out into shrieks and whistles.

Secondly, the unvoiced assumption is that CO2 is the input to the supposed feedback... but it isn't. Heat is the input to the feedback. That heat need not come from CO2's greenhouse effect. It could come from anywhere. Also the output of the feedback would have to be heat, in the form of water vapour's greenhouse effect. So, it follows that the heat output of the feedback can also be its own input.

So, here is a slight problem:  We are required to accept that the climate contains a positive (amplifying) feedback loop whose output is greater than its input... but at the same time, its output IS its input.

Commonsense says that cannot work. It would be like connecting the guitar socket of an amplifier to the speaker socket. (Don't try it, you'll blow it) No amplifier can work if the input and output are joined together.  All that would happen is that as soon as you have any gain, however slight, the whole thing would break out into oscillation.

When you think this suggestion through properly it seems far less plausible, does it not?

The problem with the 'Tipping point' theory

Regional and highly temperature sensitive mechanisms.. but immune to regional weather?

Climate activists claim that in spite of the amount of warming caused by human activities being so small, a stage will soon be reached at which this warming will nevertheless put us over a tipping point at which irreversible changes to weather systems will take place.

The basic issue with this hypothesis is that the Earth experiences far larger regional temperature changes in the normal course of the seasons. For example, temperatures in the mild climate of Britain can range from -20C to +30C over the course of a year. Changes of 10C from one day to the next are not uncommon.

Climate activists reply that these are regional weather changes, whereas they are concerned with the average temperature of the whole planet. Small changes in this average, they say,  are what will trigger disaster. Not local, day-to-day, or yearly changes.

The problem with their argument is that most of the 'tipping points' they describe are themselves regional in nature. For example, the melting of Arctic sea ice. This makes it rather implausible that such tipping-point  mechanisms could be immune to regional, seasonal temperature changes. The Arctic, after all, also experiences seasonal temperature changes. In its case, from just above freezing to an eye-watering -35C.

The above graph, courtesy of, illustrates that the 'global warming' over the course of half a century is so much smaller than the temperature variations throughout the year, that it is hard to see how any 'tipping point' to which the former might be sensitive, would not be trggered by the latter anyway. If such a tipping point existed, then it would have to be positioned just a degree or two above that 35C range, and commonsense says it would have been triggered by an unusually warm summer (Well, unusually less cold might be a better description!)  at some point in the past.

This is figuratively like being asked to believe that a pin dropping during an earthquake was the cause of a house falling. Whereas, the earthquake itself could not touch it. There is an illustration using sound of the relative size of 'global warming' compared to daily and seasonal temperature changes here. It's not meant to be rigorous science, but it may help to put it into perspective better than a mere graph.

Also, bear in mind that these purported tipping point mechanisms would, if they existed, take a very long time to reset themselves.  So, once triggered, the tipping point cannot be triggered again, at least not on a human timescale.

Thus we are expected to believe that a 2C change in global average temperature can trigger a 'tipping point mechanism' which is regional in location, and whose region is subject to annual changes ten or twenty times larger. Yet, seasonal changes have never, even in thousands of years, triggered this tipping point mechanism. If it had we would know, because the change is irreversible.

That sounds implausible. Very, implausible.

Gore and the Cores

Ice cores don't prove that CO2 causes warming

Gore missed the fact that temperature leads carbon dioxide. A bedrock of early climate change activism was that arctic ice cores proved carbon dioxide to be a driver of temperature changes. These ice cores cover a geological time period of several ice ages, and show temperature and CO2 changing in unison. What was not understood the time, is that temperature changes came before changes in CO2 levels.  

In spite of this myth having been thoroughly busted, it has never been edited out of climate activist publications, and still gets quoted today. At the very least this shows an attitude among activists that adhering to the truth is not important, that only  getting their version of the message across, is important.

That infamous Hockey Stick

Michael Mann's graph suggesting that temperatures had been utterly constant and unchanging from the last ice age until the modern era, has come under fire from numerous directions, and is probably already regarded as discredited by most scientists. However I wish to raise one or two more points about it.

One of the main contra-indications is the known existence of the Minoan, Roman and Medieval warm periods. We also know that just prior to the modern era, Europe underwent an unusually cold spell known as the Little Ice age. None of these are reflected in the hockey stick graph. Mann's explanation for this is that they were regional phenomena and did not affect global temperatures.

An issue I see with this explanation, is that for these supposedly local effects to not affect the overall average at all, there would have had to be opposite effects elsewhere of a precisely equal magnitude. In other words, as temperatures in Europe rose, those somewhere else would have had to go down, and by a matching amount. Furthermore the two mirror-image changes would have had to track each other over hundreds of years. Is this plausible, I ask? I suppose it is possible if something like the Gulf Stream shifted, causing one region to be warmer, another colder. Could such a an effect change the temperature across the whole of Europe, though? Not sure.

That early 20th Century warming we can't explain

An effect cannot start before its cause

1910-40 warming equals or exceeds that from 1970-2000The basis for the claim of modern CO2-induced warming is that rising temperatures since 1950 have closely tracked rising levels of CO2 since that date.

The issue with this claim is that temperatures rose equally rapidly between 1920 and 1940, in an era when use of fossil fuels was insufficient to account for this warming.

Activists seek to claim that, owing to the pause from 1940-70, the 1910-40 warming was distinct from later warming and had a different cause. Yet, there is no clearindication of what mechanism could have caused the 1910-40 warming. Since both intervals show a remarkably similar pattern, is it not more reasonable to assume that their cause was the same? In which  case, it cannot have been CO2.

Energy usage cannot explain 1910-40 warmingA basic principle of science is that if an effect still takes place when the purported cause is not present, then the theory linking cause and effect must be assumed incorrect. This must remain the case  until or unless an explanation for the anomalous effect is found. As far as I am aware, no such explanation for the early 20thC warming has been found. There have however been attempts to reduce its significance by way of 'adjusting' the temperature records, which some would view as an attempt to make the data fit the desired results.

Incidentally, high-accuracy CO2 figures have only been available since 1950, but reliable figures for fossil fuel usage go back much further, and suggest that human CO2 emissions in the early 20thC were of a much lower order than in the latter half. This makes it unlikely that human CO2 was the driver for the 1910-40 warming.

If carbon dioxide was not the driver in 1910, why should it be today?

Sea level rise

It sure is rising, but not rising as we know it, Jim...

The actual rate of sea level rise is only millimetres a year!A frequent activist statement is that sea levels are rising at an accelerating rate due to climate change, and that this will have disastrous effects for seaside towns. Usually these publications make no mention of the actual figures for sea levels. Although, some of the more alarmist publications have gone as far as to predicts sea level rises of tens of metres.

This subject is actually one of the more dangerous territories on which to make dubious claims, because unlike the weather, sea levels are relatively easy to measure, and indeed have been measured and documented for hundreds of years. Two of the authorities on the subject are the British Admiralty, and NASA satellite measurements. They both show that sea levels are rising.

Rising, at a rate of a few millimetres a year. About that width of the letter 'm' in millimetres, that is. What's more, this rate is not accelerating. It has been the same for over a century.

A century of sea level rise (red) compared to a day's tidal range (blue)For comparison purposes, the range of the tide at New York is about six feet. In the UK, tides range from three to four metres. That is well over a thousand times the amount of sea level rise per year. And, it happens twice daily.

If this continues, then by the year three thousand we shall need to have increased the height of our seawalls by about the range of the typical tide. When you see it in that perspective, the predictions of disaster are laughable.

You will nevertheless see climate activists referring to places where rising water levels are causing problems, and claiming that this is evidence of climate change. Commonsense says this cannot be so,  after all the average sea level cannot very well be rising faster in some places than in others. The real reason for the plight of people in these locations is of course due to land level changes. We know perfectly well that tectonic plates move, sometimes quite rapidly and by considerable amounts, so there is no difficulty in understanding this without resorting to climate change.

The important thing in all of this, is that measurements matter. Anyone can put out whatever hype they like about the sea covering the Statue of Liberty or whatever, but such predictions are largely meaningless without figures for sea level rise to back them up. When the actual figures are seen, the predictions do not seem to make sense at all.

Ocean acidification

Yet again, how much matters more than how scary

Even a tiny amount of acid shifts the pH of pure water by a whole unit or two. A further of-touted claim is that even if CO2 might not be causing warming, it is nevertheless dissolving in the oceans, and by way of forming carbonic acid in the water, turning those oceans acidic.

Superficially this seems a very plausible concern, and may even have won quite a few climate change sceptics over to the activist camp, on the grounds that CO2 is still harmful to the environment.  

The real situation though, is that the oceans are alkaline, not acidic. Also, the complex mixture of salts in seawater act as a 'buffer solution' making it quite hard to change the pH of the water. The site below gives a wealth of data. If you ignore its climate alarmist overtones and just consult the data, what you find is that the pH of the oceans, nominally about 8,  is reckoned to have changed by 0.11 over the industrial era.

The pH of a number of common substancesThis diagram shows the pH of various common substances. Note for example that bread is 9 times more acifidied than the oceans are alkaline. What the diagram doesn't show is that the scale is not proportional. It is base 10 logarithmic, such that a change from 6 to 5 requires not twice but ten times the amount of acid as does a change from 7 to 6.  Likewise a change from 5 to 4 requires a hundred times as much acid as the change from 7 to 6.

(You may recall that the greenhouse effect of CO2 is also logarithmic, but in that case it's a base 2 log, implying that each successive doubling of concentration causes an equal change in greenhouse effect. Here it's every tenfold increase in acid concentration that causes an equal change of pH.)

For this reason, adding tiny amounts of acid or alkali to pure water (pH 7) can change its pH by a surprisingly large amount. You'll also note that many common foods that we don't consider sour or bitter, nevertheless have a pH quite a fair way off from 7. It's only when you get to a pH of 4 or less, that you get to the foods we consider sharp-tasting, like fruit juices, and only when you get to pH 2 or thereabouts that you encounter substances which could be considered harmful through their corrosive action.  (Which is a hundred times more acidic than fruit juice, by the way)

It might look somewhat alarming that an upset stomach is only one pH unit away from acid that's capable of burning holes in metal, yet that actually represents a difference in strength of ten times. So, not quite so serious as if it had been a linear scale. It is still quite impressive that the stomach can contain acid of this strength without injury, and in fact stomach acid can dissolve the enamel off your teeth if it stays in contact with them for any time.

So again, this is very like the sea level rise claims. Yes, the oceans have 'acidified' during the industrial era, but they are not acid but alkaline, and the difference in actual alkali concentration is small. Is it enough to be significant? Your call on that one.

So, the climate change hypothesis does seem to be based on rather doubtful science. The follow-on question has to be, though, will the proposed remedial measures be effective in halting it? After all, even the problem is real, there is absolutely nothing to be gained by taking ineffective measures against it. Which brings us to the issues surrounding the proposed transition from fossil fuels to 100% renewable energy by the year 2050. For more on that, see the Energy section.

In the land of the numerically challenged, the man with the dime-store calculator is king.
The rest, lacking a means of verifying claims, just have to accept whatever they are told.