Category: Climate Change

An appeal was issued by David Andrews of the Claverton Energy Research Group, to respond to the Bath Lecture given by Nigel Lawson :-

“Dear All, this group is not meant to be a mere venting of frustration and opinion at what is perceived to be poor policy. So what would be really useful is to have the Lawson spiel with the countering fact interspersed. I can then publish this on the Claverton web site which does get a lot of hits and appears to be quite influential. Can I therefore first thank Ed Sears for making a good effort, but ask him to copy his bits into the Lawson article at the appropriate point. Then circulate it and get others to add in bits. Otherwise these good thoughts will simply be lost in the wind. Dave”

My reply of today :-

“Dear Dave, I don’t have time at the moment to answer all of Nigel Lawson’s layman ruminations, but I have written a few comments here (see below) which begin to give vent to frustration typical of that which his tactics cause in the minds of people who have some acquaintance with the actual science. The sheer volume of his output suggests an attempt to filibuster proper debate rather than foster it. To make life more complicated to those who wish to answer his what I think are absurd notions, he gives no accurate references to his supposed facts or cites any accredited, peer-reviewed documentation that could back up his various emotive generalisations and what appear to be aspersions. Regards, jo.”

https://www.thegwpf.org/nigel-lawson-the-bath-lecture/

Nigel Lawson: The Bath Lecture

Climate Alarmism Is A Belief System And Needs To Be Evaluated As Such

Nigel Lawson: Cool It

Standpoint, May 2014

This essay is based on the text of a speech given to the Institute for Sustainable Energy and the Environment at the University of Bath.

There is something odd about the global warming debate — or the climate change debate, as we are now expected to call it, since global warming has for the time being come to a halt.

[ joabbess.com : Contrary to what Nigel Lawson is claiming, there is no pause – global warming continues unabated. Of this there can be no doubt. All of the data that has been assessed – and there is a lot of it – confirms the theoretical framework – so it is odd that Nigel Lawson states otherwise, seemingly without any evidence to substantiate his assertion. Nigel Lawson appears to be taking advantage of fluctuations, or short-term wrinkles, in the records of air temperatures close to the Earth, to claim that up is down, dark is light and that truth is in error. Why are temperatures in the atmosphere close to the Earth’s surface, or “surface temperatures”, subject to variability ? Because heat can flow through matter, is the short answer. The longer answer is the interplay between the atmosphere and the oceans, where heat is being transfered between parts of the Earth system under conditions of flows such as the movement of air and water – what we call winds and ocean currents. There are detectable patterns in the flows of air and water – and some are oscillatory, so the temperature (taken at any one time) may appear to wriggle up and down (when viewed over a period of time). Despite these wobbles, the overall trend of temperature over several decades has been reliably detected. Despite Nigel Lawson’s attention to air temperatures, they are probably the least significant in detecting global warming, even though the data shows that baseline air temperatures, averaged over time, are rising. The vast proportion of heat being added to the Earth system is ending up in the oceans :-
https://www.skepticalscience.com/global-cooling-intermediate.htm
and the rise in ocean temperatures is consistent :-
https://www.skepticalscience.com/cherrypicking-deny-continued-ocean-global-warming.html
which indicates that circulatory patterns of heat exchange in the oceans have less effect on making temperatures fluctuate than the movement of masses of air in the atmosphere. This is exactly what you would expect from the study of basic physics. If you give only a cursory glance at the recent air temperatures at the surface of the Earth, you could think that temperatures have levelled off in the last decade or so, but taking a longer term view easily shows that global warming continues to be significant :-
https://data.giss.nasa.gov/gistemp/graphs_v3/
What is truly astonishing about this data is that the signal shows through the noise – that the trend in global warming is easily evident by eye, despite the wavy shakes from natural variability. For Nigel Lawson’s information, the reason why we refer to climate change is to attempt to encompass other evidence in this term besides purely temperature measurements. As the climate changes, rainfall patterns are altering, for example, which is not something that can be expressed in the term global warming. ]

I have never shied away from controversy, nor — for example, as Chancellor — worried about being unpopular if I believed that what I was saying and doing was in the public interest.

But I have never in my life experienced the extremes of personal hostility, vituperation and vilification which I — along with other dissenters, of course — have received for my views on global warming and global warming policies.

For example, according to the Climate Change Secretary, Ed Davey, the global warming dissenters are, without exception, “wilfully ignorant” and in the view of the Prince of Wales we are “headless chickens”. Not that “dissenter” is a term they use. We are regularly referred to as “climate change deniers”, a phrase deliberately designed to echo “Holocaust denier” — as if questioning present policies and forecasts of the future is equivalent to casting malign doubt about a historical fact.

[ joabbess.com : Climate change science is built on observations : all historical facts. Then, as in any valid science, a theoretical framework is applied to the data to check the theory – to make predictions of future change, and to validate them. It is an historical fact that the theoretical framework for global warming has not been falsified. The Earth system is warming – this cannot be denied. It seems to me that Nigel Lawwon usurps the truth with myth and unsubstantiated rumour, casting himself in the role of doubting dissenter, yet denying the evidence of the data. He therefore self-categorises as a denier, by the stance of denial that he takes. His denial is also an historical fact, but calling him a denier is not a value judgement. It is for each person to ascribe for themselves a moral value to the kind of denial he expresses. ]

The heir to the throne and the minister are senior public figures, who watch their language. The abuse I received after appearing on the BBC’s Today programme last February was far less restrained. Both the BBC and I received an orchestrated barrage of complaints to the effect that it was an outrage that I was allowed to discuss the issue on the programme at all. And even the Science and Technology Committee of the House of Commons shamefully joined the chorus of those who seek to suppress debate.

[ joabbess.com : Considering the general apathy of most television viewers, it is therefore quite refreshingly positive that so many people decided to complain about Nigel Lawson being given a platform to express his views about climate change, a subject about which it seems he is unqualified to speak with authority of learning. He may consider the complaints an “orchestrated barrage”. Another interpretation could be that the general mood of the audience ran counter to his contributions, and disagreed with the BBC’s decisiont to permit him to air his contrarian position, to the point of vexation. A parallel example could be the kind of outrage that could be expressed if Nigel Lawson were to deny that the Earth is approximately spherical, that gravity means that things actually move out to space rather than towards the ground, or that water is generally warmer than ice. He should expect opposition to his opinions if he is denying science. ]

In fact, despite having written a thoroughly documented book about global warming more than five years ago, which happily became something of a bestseller, and having founded a think tank on the subject — the Global Warming Policy Foundation — the following year, and despite frequently being invited on Today to discuss economic issues, this was the first time I had ever been asked to discuss climate change. I strongly suspect it will also be the last time.

The BBC received a well-organised deluge of complaints — some of them, inevitably, from those with a vested interest in renewable energy — accusing me, among other things, of being a geriatric retired politician and not a climate scientist, and so wholly unqualified to discuss the issue.

[ joabbess.com : It is a mark of integrity to put you money where your mouth is, not an indicator on insincerity. It is natural to expect people who accept climate change science to be taking action on carbon dioxide emissions, which includes investment in renewable energy. ]

Perhaps, in passing, I should address the frequent accusation from those who violently object to any challenge to any aspect of the prevailing climate change doctrine, that the Global Warming Policy Foundation’s non-disclosure of the names of our donors is proof that we are a thoroughly sinister organisation and a front for the fossil fuel industry.

As I have pointed out on a number of occasions, the Foundation’s Board of Trustees decided, from the outset, that it would neither solicit nor accept any money from the energy industry or from anyone with a significant interest in the energy industry. And to those who are not-regrettably-prepared to accept my word, I would point out that among our trustees are a bishop of the Church of England, a former private secretary to the Queen, and a former head of the Civil Service. Anyone who imagines that we are all engaged in a conspiracy to lie is clearly in an advanced stage of paranoia.

The reason why we do not reveal the names of our donors, who are private citizens of a philanthropic disposition, is in fact pretty obvious. Were we to do so, they, too, would be likely to be subject to the vilification and abuse I mentioned earlier. And that is something which, understandably, they can do without.

That said, I must admit I am strongly tempted to agree that, since I am not a climate scientist, I should from now on remain silent on the subject — on the clear understanding, of course, that everyone else plays by the same rules. No more statements by Ed Davey, or indeed any other politician, including Ed Milliband, Lord Deben and Al Gore. Nothing more from the Prince of Wales, or from Lord Stern. What bliss!

But of course this is not going to happen. Nor should it; for at bottom this is not a scientific issue. That is to say, the issue is not climate change but climate change alarmism, and the hugely damaging policies that are advocated, and in some cases put in place, in its name. And alarmism is a feature not of the physical world, which is what climate scientists study, but of human behaviour; the province, in other words, of economists, historians, sociologists, psychologists and — dare I say it — politicians.

[ joabbess.com : Au contraire, I would say to Nigel Lawson. At root, climate change is very much a scientific issue. Science defines it, describes it and provides evidence for it. Climate change is an epistemological concern, and an ontological challenge. How we know what we know about climate change is by study of a very large number of results from data collection and other kinds of research. The evidence base is massive. The knowledge expressed in climate change science is empirical – based on observations – which is how we are sure that what we know is assured. There is still scope for uncertainty – will the surface temperatures rise by X plus or minus some Y, owing to the dynamic between the atmosphere, the oceans, the ice cover and the land masses ? The results of the IPCC assessments are that we pretty much know what X is, and we have an improved clarity on a range of values for Y. The more science is done, the clearer these numbers emerge. Knowledge increases as more science is done, which is why the IPCC assessments are making firmer conclusions as time passes. Climate change science does not make value judgements on its results. It concludes that sea levels are rising and will continue to rise; that rainfall patterns are changing and will continue to change; that temperatures are rising and will continue to rise under current economic conditions and the levels of fossil fuel use and land use. Science describes the outcomes of these and other climate changes. It is for us as human beings, with humanity in our hearts, to place a meaning on predicted outcomes such as crop and harvest failures, displacement of peoples, unliveable habitats, loss of plant and animal species, extreme weather. You cannot take the human out of the scientist. Of course scientists will experience alarm at the thought of these outcomes, just as the rest of society will do. The people should not be denied the right to feeling alarm. ]

And en passant, the problem for dissenting politicians, and indeed for dissenting climate scientists for that matter, who certainly exist, is that dissent can be career-threatening. The advantage of being geriatric is that my career is behind me: there is nothing left to threaten.

[ joabbess.com : Climate change science is not something you can “dissent” from if you are at all versed in it. For those who question any part of climate change science from inside the community of those who have appropriate knowledge and learning, their position is not one of dissent, but of being unable to assent completely to the conclusions of their peers. They lack a capacity to fully assent to the results of other people’s research because their own research indicates otherwise. As responsible members of the science community, they would then put their research conclusions and the research conclusions of others to the test. There is an integrity in this kind of questioning. It is a valid position, as long as the questions are posed in the language of scientific enquiry, and answered with scientific methods. For example, the Berkeley BEST team had questions about the evidence of global warming and set out to verify or falsify the results of others. Their own research led them to become convinced that their peers had been correct in the their conclusions. This is how science comes to consensus. Nigel Lawson should fund research in the field if he wishes to be taken seriously in denying the current consensus in climate change science. Instead of which, he invests in the publication of what appears to be uncorroborated hearsay and emotive politicking. ]

But to return: the climate changes all the time, in different and unpredictable (certainly unpredicted) ways, and indeed often in different ways in different parts of the world. It always has done and no doubt it always will. The issue is whether that is a cause for alarm — and not just moderate alarm. According to the alarmists it is the greatest threat facing humankind today: far worse than any of the manifold evils we see around the globe which stem from what Pope called “man’s inhumanity to man”.

[ joabbess.com : Nigel Lawson doesn’t need to tell anyone that weather is changeable and that climate changes. They can see it for themselves if they care to study the data. Climate change science has discovered that the current changes in the climate are unprecedented within at least the last 800,000 years. No previous period of rapid climate change in that era has been entirely similar to the changes we are experiencing today. This is definite cause for alarm, high level alarm, and not moderate. If there is a fire, it is natural to sound the alarm. If there is a pandemic, people spread the news. If there is a risk, as human beings, we take collective measures to avoid the threat. This is normal human precautionary behaviour. It is unreasonable for Nigel Lawson to insist that alarm is not an appropriate response to what is patently in the process of happening. ]

Climate change alarmism is a belief system, and needs to be evaluated as such.

[ joabbess.com : Belief in gravity, or thinking that protein is good to eat are also belief systems. Everything we accept as normal and true is part of our own belief system. For example, I believe that Nigel Lawson is misguided and has come to the wrong conclusions. The evidence lies before me. Is my opinion to be disregarded because I have a belief that Nigel Lawson is incorrect ? ]

There is, indeed, an accepted scientific theory which I do not dispute and which, the alarmists claim, justifies their belief and their alarm.

This is the so-called greenhouse effect: the fact that the earth’s atmosphere contains so-called greenhouse gases (of which water vapour is overwhelmingly the most important, but carbon dioxide is another) which, in effect, trap some of the heat we receive from the sun and prevent it from bouncing back into space.

Without the greenhouse effect, the planet would be so cold as to be uninhabitable. But, by burning fossil fuels — coal, oil and gas — we are increasing the amount of carbon dioxide in the atmosphere and thus, other things being equal, increasing the earth’s temperature.

But four questions immediately arise, all of which need to be addressed, coolly and rationally.

First, other things being equal, how much can increased atmospheric CO2 be expected to warm the earth? (This is known to scientists as climate sensitivity, or sometimes the climate sensitivity of carbon.) This is highly uncertain, not least because clouds have an important role to play, and the science of clouds is little understood. Until recently, the majority opinion among climate scientists had been that clouds greatly amplify the basic greenhouse effect. But there is a significant minority, including some of the most eminent climate scientists, who strongly dispute this.

[ joabbess.com : Simple gas chemistry and physics that is at least a century old is evidence that carbon dioxide allows sunlight to pass right through to warm the Earth, which then emits infrared light because it has warmed up. When the infrared radiation is emitted, the Earth cools down. Infrared is partially blocked by carbon dioxide, which absorbs it, then re-radiates it, partially back to the Earth, which warms up again. Eventually, the warming radiation will escape the carbon dioxide blanket, but because of this trapping effect, the net result is for more heat to remain in the atmosphere close to the Earth’s surface than you would expect. This is the main reason why the temperature of the Earth’s surface is warmer than space. As carbon dioxide accumulates in the atmosphere, the warming effect will be enhanced. This is global warming and it is undisputed by the overwhelming majority of scientists. Climate sensitivity, or Equilibrium Climate Sensitivity (ECS) is a calculated measure of the total temperature change that would be experienced (after some time) at the surface of the Earth for a doubling of atmospheric carbon dioxide concentrations compare to the pre-industrial age. The Transient Climate Response (TCR) is a measure of the temperature change that would be experienced in the shorter-term for a doubling of atmospheric carbon dioxide concentrations. The TCR can be easily calculated from basic physics. The shorter-term warming will cause climate change. Some of the changes will act to cool the Earth down from the TCR (negative feedbacks). Some of the changes will act to heat the Earth up from the TCR (positive feedbacks). These are some disagreements about the ECS, such as the net effects from the fertilisation effect of carbon dioxide on plant growth, the net effects of changes in weather and cloud systems, and the net effects of changes in ocean and atmospheric circulation. However, evidence from the deep past (paleoclimatology) is helping to determine the range of temperatures that ECS could be. ]

Second, are other things equal, anyway? We know that, over millennia, the temperature of the earth has varied a great deal, long before the arrival of fossil fuels. To take only the past thousand years, a thousand years ago we were benefiting from the so-called medieval warm period, when temperatures are thought to have been at least as warm, if not warmer, than they are today. And during the Baroque era we were grimly suffering the cold of the so-called Little Ice Age, when the Thames frequently froze in winter and substantial ice fairs were held on it, which have been immortalised in contemporary prints.

[ joabbess.com : The Medieval Warming Period (or Medieval Warm Period) was just a blip compared to the current global warming of the last 150 years. And the Little Ice Age was also a minor anomaly, being pretty much confined to the region of Europe, and some expect could have become the Rather Much Longer Icy Period had it not been for the use of fossil fuels, which warmed Europe up again. Burning coal and other fossil fuels releases carbon that would have originally been in the atmosphere in the form of carbon dioxide millions of years ago, that trees and other plants used to grow. Geological evidence shows that surface temperatures at those times were warmer than today. ]

Third, even if the earth were to warm, so far from this necessarily being a cause for alarm, does it matter? It would, after all, be surprising if the planet were on a happy but precarious temperature knife-edge, from which any change in either direction would be a major disaster. In fact, we know that, if there were to be any future warming (and for the reasons already given, “if” is correct) there would be both benefits and what the economists call disbenefits. I shall discuss later where the balance might lie.

[ joabbess.com : The evidence from the global warming that we have experienced so far since around 1880 is almost universally limiting in terms of the ability of species of animals and plants to survive. There are tiny gems of positive outcomes, compared to a sand pit of negatives. Yes, of course it matters. The mathematics of chaos with strong perturbations to any system do not permit it to coast on a precarious knife-edge for very long. Sooner or later there will be a major alteration, and the potential for some milder probable outcomes will collapse. ]

And fourth, to the extent that there is a problem, what should we, calmly and rationally, do about it?

[ joabbess.com : The most calm and rational thing to do is to compile all the evidence and report on it. Oh yes, we’ve already done that. It’s called the Intergovernmental Panel on Climate Change or IPCC. The concluisons of the compilation of over 100 years of science is that global warming is real, and it’s happening now, and that there is a wide range of evidence for climate change, and indicators that it is a major problem, and that we have caused it, through using fossil fuels and changing how we use land. ]

It is probably best to take the first two questions together.

According to the temperature records kept by the UK Met Office (and other series are much the same), over the past 150 years (that is, from the very beginnings of the Industrial Revolution), mean global temperature has increased by a little under a degree centigrade — according to the Met Office, 0.8ºC. This has happened in fits and starts, which are not fully understood. To begin with, to the extent that anyone noticed it, it was seen as a welcome and natural recovery from the rigours of the Little Ice Age. But the great bulk of it — 0.5ºC out of the 0.8ºC — occurred during the last quarter of the 20th century. It was then that global warming alarmism was born.

[ joabbess.com : Nigel Lawson calls it “alarmism”. I call it empirical science. And there are many scientific explanations for what he calls “fits and starts”, it’s just that they’re written in research papers, so he will probably never read them, going on his lack of attention to research publications in the past. ]

But since then, and wholly contrary to the expectations of the overwhelming majority of climate scientists, who confidently predicted that global warming would not merely continue but would accelerate, given the unprecedented growth of global carbon emissions, as China’s coal-based economy has grown by leaps and bounds, there has been no further warming at all. To be precise, the latest report of the Intergovernmental Panel on Climate Change (IPCC), a deeply flawed body whose non-scientist chairman is a committed climate alarmist, reckons that global warming has latterly been occurring at the rate of — wait for it — 0.05ºC per decade, plus or minus 0.1ºC. Their figures, not mine. In other words, the observed rate of warming is less than the margin of error.

[ joabbess.com : It is not valid for Nigel Lawson to claim that there has been “no further warming at all”. Heat accumulation continues to be documented. Where is Nigel Lawson’s evidence to support his claim that the IPCC is a “deeply flawed body” ? Or is that another one of his entirely unsubstantiated dismissals of science ? Does he just fudge the facts, gloss over the details, pour scorn on scientists, impugn the academies of science, play with semantics, stir up antipathy, wave his hands and the whole history of science suddenly vanishes in a puff of dismissive smoke ? I doubt it ! Nigel Lawson says “the observed rate of warming is less than the margin of error.” This is ridiculous, because temperature is not something that you can add or subtract, like bags of sugar, or baskets of apples, or Pounds Sterling to the Global Warming Policy Foundation’s public relations fund. Two degrees Celsius, or Centigrade, is not twice as warm as one degree Celsius. 30 degrees C doesn’t indicate twice as much heat as 15 degrees C, or require twice as much heating. The range of figures that Nigel Lawson is quoting, minus 0.05 degrees C plus or minus 0.1 degrees C, that is, somewhere between a cooling of 0.05 degrees C and a warming of 0.15 degrees C, is a calculation of temperature trends averaged over the whole Earth’s surface for the last 15 years :-
https://www.climatechange2013.org/images/uploads/WGIAR5_WGI-12Doc2b_FinalDraft_Chapter09.pdf (Box 9.2)
It is not surprising that over such a short timescale it might appear that the Earth as experienced a mild cooling effect. In the last 15 years there have been a couple of years far hotter than average, and these spike the calculated trend. For example, 1998 was much hotter than the years before or after it, so if you were just to compare 1998 with 2008, it would look like the Earth is cooling down. But who would be foolish enough to look at just two calendar years of the data record on which to base their argument ? The last 15 years have to be taken in context. In “Climate Change 2013 : The Physical Science Basis”, the IPCC report from Working Group 1, in the Summary for Policymakers, page 5, Section B1, the IPCC write :-
https://www.climatechange2013.org/images/report/WG1AR5_ALL_FINAL.pdf
“In addition to robust multi-decadal warming, global mean surface temperature exhibits substantial decadal and interannual variability […] Due to natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends. As one example, the rate of warming over the past 15 years (1998–2012; 0.05 [–0.05 to 0.15] °C per decade), which begins with a strong El Niño, is smaller than the rate calculated since 1951 (1951–2012; 0.12 [0.08 to 0.14] °C per decade).” (El Niño is a prominent pattern of winds and ocean currents in the Pacific Ocean with two main states – one that tends to produce a warming effect on the Earth’s surface temperatures, and the other, La Niña, which has a general cooling effect.) ] In other words, in the last fifteen years, the range of rate of change of temperature is calculated to be somewhere between the surface of the planet cooling by 0.05 degrees Centigrade, up to warming by 0.15 degrees Centigrade :-
https://data.giss.nasa.gov/gistemp/graphs_v3/Fig.C.gif
https://www.climate4you.com/GlobalTemperatures.htm#Recent%20global%20satellite%20temperature
However, this calculation of a trend line does not take account of three things. First, in the last decade or so, the variability of individual years could mask a trend, but relative to the last 50 years, everything is clearly hotter on average. Secondly, temperature is not a “discrete” quantity, it is a continuous field of effect, and it is going to have different values depending on location and time. The temperature for any January to December is only going to be an average of averages. If you were to measure the year from March to February instead, the average of averages could look different, because of the natural variability. Thirdly, there are lots of causes for local and regional temperature variability, all concurrent, so it is not until some time after a set of measurements has been taken, and other sets of measurements have been done, that it is possible to determine that a substantial change has taken place. ]

And that margin of error, it must be said, is implausibly small. After all, calculating mean global temperature from the records of weather stations and maritime observations around the world, of varying quality, is a pretty heroic task in the first place. Not to mention the fact that there is a considerable difference between daytime and night-time temperatures. In any event, to produce a figure accurate to hundredths of a degree is palpably absurd.

[ joabbess.com : Nigel Lawson could be said to mislead in his explanation of what “a figure accurate to hundredths of a degree” implies. Temperature is measured on an arbitrarily decided scale. To raise the whole of the Earth surface temperatures by 1 degree Celsius requires a lot of extra trapped energy. The surface temperature of the Earth is increasing by the absorption of energy that amounts roughly to 2 trillion Hiroshima atombic bombs since 1998, or 4 Hiroshimas a second. That is not a small number, although it has to be seen in the full context of the energy flows in and out of the Earth system :-
https://www.skepticalscience.com/4-Hiroshima-bombs-per-second-widget-raise-awareness-global-warming.html
https://blogs.discovermagazine.com/imageo/2013/12/03/climate-bomb-redux/#.U2tlfaI-hrQ
Nigel Lawson credits the global temperature monitoring exercise as “heroic”, but then berates its quality. However, climate change scientists do already appreciate that there are differences between daytime and nighttime temperatures – it is called the diurnal range. Besides differences between years, it is known that there are also differences between seasons, and latitudes, and climatic zones. Scientists are not claiming an absolute single value for the temperature of the Earth, accurate to within hundredths of a degree – that’s why they always give a margin of error. What is astonishing from reviews of the data is something that Nigel Lawson has completely missed. Global warming appears to have fractal resolution – that is – at whatever geographical scale you resolve the data, the trend in most cases appears to be similar. If you take a look at some of the websites offering graphs, for example :-
https://www.rimfrost.no/
https://data.giss.nasa.gov/gistemp/station_data/
the global warming trend is seen to be generally similar when averaged locally, regionally or at the global scale. This is an indicator that the global warming signal is properly being detected, as these trend lines are more or less what you would expect from basic physics and chemistry – the more carbon dioxide in the air, the more heat gets trapped, and the rate of carbon dioxide accumulation in the atmosphere has seen similar trendlines :-
https://cdiac.esd.ornl.gov/trends/co2/recent_mauna_loa_co2.html ]

The lessons of the unpredicted 15-year global temperature standstill (or hiatus as the IPCC calls it) are clear. In the first place, the so-called Integrated Assessment Models which the climate science community uses to predict the global temperature increase which is likely to occur over the next 100 years are almost certainly mistaken, in that climate sensitivity is almost certainly significantly less than they once thought, and thus the models exaggerate the likely temperature rise over the next hundred years.

[ joabbess.com : I repeat : there is no pause. The IPCC are not claiming that global warming has stopped, only that there is an apparent “hiatus” in global surface temperature averages. Some scientists have concluded from their work that Climate Sensitivity is less than once feared. However, Climate Sensitivity is calculated for an immediate, once-only doubling of carbon dioxide in the atmosphere, whereas the reality is that carbon dioxide is continuing to build up in the atmosphere, and if emissions continue unabated, there could be a tripling or quadrupling of carbon dioxide concentrations in the atmosphere, which would mean that you would need to multiply the Climate Sensitivity by 1.5 or 2 to arrive at the final top temperature – higher than previously calculated, regardless of whether the expected Climate Sensitivity were to be less than previously calculated. It is therefore illogical for Nigel Lawson to extrapolate from his understanding that Climate Sensitivity is lower than previously calculated to his conclusion that the final level of global warming will be lower than previously calculated. The more carbon dioxide we emit, the worse it will be. ]

But the need for a rethink does not stop there. As the noted climate scientist Professor Judith Curry, chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, recently observed in written testimony to the US Senate:
“Anthropogenic global warming is a proposed theory whose basic mechnism is well understood, but whose magnitude is highly uncertain. The growing evidence that climate models are too sensitive to CO2 has implications for the attribution of late-20th-century warming and projections of 21st-century climate. If the recent warming hiatus is caused by natural variability, then this raises the question as to what extent the warming between 1975 and 2000 can also be explained by natural climate variability.”

[ joabbess.com : The IPCC reports constitute the world’s best attempts to “rethink” Climate Change. Professor Judith Curry, in the quotation given by Nigel Lawson, undervalues a great deal of her colleagues’ work by dismissing their valid attribution of Climate Change to the burning of fossil fuels and the change in land use. ]

It is true that most members of the climate science establishment are reluctant to accept this, and argue that the missing heat has for the time being gone into the (very cold) ocean depths, only to be released later. This is, however, highly conjectural. Assessing the mean global temperature of the ocean depths is — unsurprisingly — even less reliable, by a long way, than the surface temperature record. And in any event most scientists reckon that it will take thousands of years for this “missing heat” to be released to the surface.

[ joabbess.com : That the oceans are warming is not conjecture – it is a statement based on data. The oceans have a far greater capacity for heat retention than the atmosphere, so yes, it will take a long time for heat in the oceans to re-emerge into the atmosphere. However, the processes that directed heat into the oceans rather than the atmosphere in recent years could easily reverse, and in a short space of time the atmosphere could heat up considerably. In making his arguments, Nigel Lawson omits to consider this eventuality, which lowers considerably the value of his conclusions. ]

In short, the CO2 effect on the earth’s temperature is probably less than was previously thought, and other things — that is, natural variability and possibly solar influences — are relatively more significant than has hitherto been assumed.

[ joabbess.com : Nothing about science has changed. The Earth system continues to accumulate heat and respond to that. Carbon dioxide still contributes to the Greenhouse Effect, and extra carbon dioxide in the air will cause further global warming. The Transient Climate Response to carbon dioxide is still apparently linear. The Equilibrium Climate Sensitivity is still calculated to be roughly what it always has been – but that’s only for a doubling of atmospheric carbon dioxide. If more methane is emitted as a result of Arctic warming, for example, or the rate of fossil fuel use increases, then the temperature increase of the Earth’s surface could be more than previously thought. Natural variability and solar changes are all considered in the IPCC reports, and all calculations and models take account of them. However, the obvious possibility presents itself – that the patterns of natural variability as experienced by the Earth during the last 800,000 years are themseles being changed. If Climate Change is happening so quickly as to affect natural variability, then the outcomes could be much more serious than anticipated. ]

But let us assume that the global temperature hiatus does, at some point, come to an end, and a modest degree of global warming resumes. How much does this matter?

The answer must be that it matters very little. There are plainly both advantages and disadvantages from a warmer temperature, and these will vary from region to region depending to some extent on the existing temperature in the region concerned. And it is helpful in this context that the climate scientists believe that the global warming they expect from increased atmospheric CO2 will be greatest in the cold polar regions and least in the warm tropical regions, and will be greater at night than in the day, and greater in winter than in summer. Be that as it may, studies have clearly shown that, overall, the warming that the climate models are now predicting for most of this century (I referred to these models earlier, and will come back to them later) is likely to do more good than harm.

[ joabbess.com : The claim that warming will “overall […] do more good than harm” is erroneous, according to Climate Change Science. ]

…

Global warming orthodoxy is not merely irrational. It is wicked.

[ joabbess.com : My conclusions upon reading this lecture are that the evidence suggests that Nigel Lawson’s position is ill-informed. He should read the IPCC reports and re-consider. ]