Calentamiento Global y Medio AmbienteIniciosemana del 18 de MAYO al 24 de MAYO

In the climate debate, hear both sides

By Christopher Monckton of Brenchley

In May 2015, the Pennant, a biannual magazine for retired UK armed forces personnel, carried an article entitled The Earth’s Climate by Rob Varley, chief executive of the Met Office, the world’s oldest national weather bureau.

The Met Office article does not represent a fair or balanced summary of the science on the climate question. This detailed response, prepared at the suggestion of a reader of the Pennant, is illustrated with some 50 well-sourced graphs that are intended to be clear at a glance. The key facts that restore balance to the discussion may be gained from these graphs in five minutes.

The greenhouse effect, with the consequence that (all other things being equal) our returning to the atmosphere some minuscule fraction of the 30,000 μmol mol–1 CO2 formerly resident there may cause some warming, has been posited hypothetically, demonstrated empirically and explained theoretically, even at the quantum scale.

However, the questions whether all other things are equal, and how much warming our sins of emission may cause, and whether the cost of mitigation today is less than that of adaptation the day after tomorrow, are by no means settled.

Are today’s temperature changes unprecedented?

Mr Varley says:

“… warming of the global climate system is unequivocal. Many of the observed changes are unprecedented over decades to millennia. In just over 100 years, the world’s surface has warmed by around 0.85 Cº. This represents a significant rate of increase in mean global temperature …”

Here as elsewhere, Mr Varley’s statement only gives one side of the story. His implication that the warming of five-sixths of a Celsius degree over a century is “unprecedented” is false. The following are among the points he has omitted:

Ø The Central England Temperature Record, which is not a bad proxy for global temperature change, shows warming from 1693-1733 at a rate exceeding 4 Cº/century equivalent – more than twice the maximum rate sustained for 15 years or more in the 20th century. Therefore, there is nothing special about the 20th-century warming rate.

Ø Our associates at have compiled a list of some 500 peer-reviewed papers demonstrating by measurement of proxies for pre-thermometer temperatures that the Middle Ages were warmer than the present. As Ljungqvist (2010) shows, the Roman and mediaeval warm periods were at least as warm as the present, and the mediaeval warming rate was not much less than the rate observed in the 20th century:


Was the glacial-to-interglacial global warming as little as 3 Cº?

Mr Varley says:

“To provide some kind of perspective, the global temperature is estimated to have increased by 3-8 Cº over the last deglaciation, occurring in two main steps between 17,500 and 10,000 years ago …”

However, again several balancing considerations have been omitted:

Ø Jouzel et al. (2007) have shown that throughout the past 810,000 years global mean surface temperature has varied by less than 3.5 Cº either side of the long-run mean. The climate object is near-perfectly thermostatic. It is, therefore, difficult to get global temperature to change by much:


Ø At present we are about 1 Cº above that long-run mean, but each of the previous three interglacial warm periods was warmer than the present.

Ø The most recent such warm period was 2.5 Cº warmer than the present. So there is nothing “unprecedented” about present-day temperatures.

Was 2014 “the warmest year on record”? And does it matter?

Mr Varley says:

“The WMO confirmed that globally 2014 was the warmest year on record, with 14 of the 15 hottest years occurring this century.”

Yet again we are given only part of the story. The following are among the relevant considerations omitted or erroneously presented:

Ø When one talks of “the warmest year on record”, the “record” only goes back to 1850 (HadCRUT4), or 1880 (NASA GISS and NCDC), or 1979 (RSS and UAH). The first three depend on the same historical climate data network. They all show 2014 as the warmest year since 1850 (or 1880). So what?

Ø The RSS and UAH satellite datasets do not show 2014 as the warmest year. It would have been fairer if this fact had been mentioned.

Ø The Mediaeval Optimum was warmer than today by up to 3 Cº in some places. The Roman, Minoan and Old Kingdom climate optima were also warmer. The Holocene Climate Optimum was warmer than today for 4000 years.

Ø According to the two satellite datasets, there has been no global warming at all for more than 18 years. The trend is zero. In a briefing on global warming, you should surely have mentioned that fact.


Mr Varley says:

“Closer to home, Met Office statistics show that in 2014 the UK as a whole experienced its warmest year on record with the eight warmest years in this series all occurring since 2002. It was also the warmest year on record in the Central England Temperature series which extends back to 1659.”

Yet again, balancing considerations are omitted:

Ø Cherry-picking an individual year, or a selection of individual years, is not how statistical trends on time-series are determined.

Ø The Central England Temperature Record, is cited, but with no mention of the fact that from 1693-1733 the rate of global warming was twice that which occurred over any period of 15 years or more during the 20th century.

What is the ideal UK and global temperature?

Mr Varley says:

“The UK mean temperature for 2014 was 9.9 ºC, 1.1 Cº above the 1981-2010 long-term average and the warmest year in the UK series …”

The balancing considerations:

Ø Cherry-picking an individual year in an individual territory tells us nothing about the global temperature trend, which has been statistically indistinguishable from zero for at least a quarter of a century on the satellite measures, notwithstanding record increases in CO2 concentration.

Ø In a cold country like Britain, what problems would be caused by the temperature warming up a little? The human body works best at about 19 ºC, yet the U.K. average temperature in 2014 was less than 10 ºC.

Ø And what, in any event, is the ideal global (or, for that matter, UK) temperature? Unless we are told that, we cannot be at all sure that an increase of 1 Cº in UK surface temperature is anything other than welcome.

Stretching the vertical axis of the temperature graph

Next, Mr Varley reproduces a graph of global temperature change since 1850 published by the IPCC in its 2013 Fifth Assessment Report. The IPCC stretched the graph along its vertical axis (and Mr Varley has stretched it a little further):


Ø Such alterations of the aspect ratio by accentuating the vertical axis are calculated to make the actually rather small change in global temperature over the period seem bigger than it was.

Ø In the upper panel of the image, we have restored the aspect ratio of the IPCC’s original graph. In the lower panel, we have reduced the vertical emphasis to show that the apparent steepness of the temperature increase in the IPCC’s graph is merely an artefact of the choice of aspect ratio. Vertical exaggeration, now commonplace in climate science, is a rather less than honest graphical technique.

Imagined effects of global warming

Mr Varley says:

“In addition to the Earth’s surface temperature, many tens of other climate variables are measured, extending from high in the atmosphere to the depths of the oceans. These are analysed at academic and research centres around the world, with thousands of scientists pooling their findings and expertise to build a picture of past and current climate. Emerging from these observations is evidence of change: global and regional temperatures are increasing; Arctic sea ice, mountain glaciers and snow cover are shrinking; warming oceanic waters are expanding, leading to sea level rise; atmospheric humidity is rising as a warmer atmosphere’s capacity to hold water increases; the frequency of rainfall and temperature extremes has increased. These changes are already impacting on natural and human systems.”

Now for the balance:

Ø Of course there is “evidence of change”: the climate has been changing for 4.5 billion years and it will continue to change.

Ø No one denies that the climate changes. The question is whether Man has had or may yet have a significant effect, and whether that effect, if significant, will be beneficial or detrimental.

Ø Mr Varley makes no mention of the real difficulties in distinguishing between natural and anthropogenic climate change.

Ø Mr Varley’s statement that global and regional temperatures are increasing is scientifically meaningless in the absence of a stated start date.

Ø Global temperature has not increased for more than 18 years, and has not increased significantly in the quarter of a century since the IPCC’s First Assessment Report in 1990.

Ø Some regions, such as Antarctica and central Africa, have scarcely warmed, if at all.

Ø Global temperatures are lower than during previous climate optima during the Holocene.

Ø Global temperatures are also lower than in each of the previous four interglacial warm periods.

Ø Mr Varley says Arctic sea ice, mountain glaciers and snow cover are shrinking, but he is silent on the fact that Antarctic sea ice has grown; that mountain glaciers in the Himalayas, in Greenland and in Antarctica show a long-established and unalarming pattern of advance and retreat; and that winter snow cover in the Northern Hemisphere shows no particular trend:


Ø Mr Varley says warming oceanic waters are expanding, leading to sea level rise, but he is very careful not to quantify this. According to the GRACE gravitational-recovery satellites, sea level actually fell from 2003-2008:


Ø According to the ENVISAT sea-level satellite, sea level rose from 2004-2012 at a mean rate equivalent to just 1.3 inches per century:


Ø The inter-calibration errors between the series of laser-altimetry satellites from which the “official” sea-level record is obtained are greater than the sea level rise they purport to show.


Ø Tide gauges and benchmarks show very little sea level rise. And why should there be much sea-level rise? The ARGO bathythermographs show that in the first 11 years of the record, 2004-2014, the ocean to a depth of 1900 m warmed at a rate equivalent to 0.23 Cº per century:


Ø Mr Varley says that atmospheric humidity is increasing: but not all records show this, as the following chart of column water vapor demonstrates:


Ø Mr Varley says the frequency of temperature extremes has increased. However, the weather is like the cricket: new records are set somewhere in the system all the time. It is the nature of the object.

Ø Significantly, there have been just about as many cold-weather records as hot-weather records set in recent years, even though theory would lead us to suspect fewer cold-weather records in a rapidly warming world (though it is not warming by much). And more all-time high temperature records were set in the 1930s than in any decade since:


Ø Mr Varley says the frequency of rainfall extremes has increased. Yet the IPCC, both in its 2012 report on extreme weather and in its 2013 Fifth Assessment Report, draws no such conclusion.

Ø On the contrary, the IPCC says there is little or no evidence that such rainfall changes that have occurred are anthropogenic.

Ø Mr Varley’s own own Met Office records tell a story different from Mr Varley’s. For instance, the longest annual national rainfall record, the quarter of a millennium in England and Wales, shows little change.

Ø There is also very little change in U.S. annual rainfall over the 48 mainland states:


In fact, as the Global Warming Policy Foundation recently concluded, deaths from extreme weather are currently at an all-time low, notwithstanding record increases both in greenhouse-gas concentrations and in global population over the period covered by its graph:


Is sea ice really declining rapidly?

Next, Mr Varley shows a graph of September sea-ice extent in the Arctic similar to the following:


What he does not show is the Antarctic sea-ice extent. It has increased somewhat:


Moreover, in the Arctic as in the Antarctic, the amplitude of the seasonal variation dwarfs the relatively small changes in sea-ice extent:


Mr Varley says:

“Observations of the climate to current day show that the poles have warmed at twice the global average, and computer model predictions suggest this trend will continue.”

Here is a more complete picture:

Ø In recent decades the south polar region has shown little or no warming, as even the IPCC concedes.

Ø The extent of global sea ice shows remarkably little change over the past 35 years:


Ø “Computer model predictions” of 1.4-4.5 Cº global warming per CO2 doubling have remained unchanged for 36 years: yet the IPCC’s medium-term global warming predictions made 25 years ago have proven exaggerated by a factor of two. Would it not have been appropriate at least to mention the models’ continuing exaggerations?

Ø Likewise, there is now a substantial list of papers in the reviewed journals suggesting that climate sensitivity could be as little as one-fifth of the IPCC’s current central estimate of about 3 Cº per CO2 doubling. Mr Varley has given only one side of the climate-sensitivity case.

Rising CO2 concentration and its effect on global temperature

Mr Varley says:

“Since pre-industrial times, the atmospheric concentration of CO2 has risen by 40% to a level unprecedented in at least 800,000 years … This has led to an enhanced greenhouse effect.

“Scientists have calculated that more than half of the observed warming since the mid 20th century was caused by the increase in man-made greenhouse gases.”

Once again, there is plenty of balancing evidence:

Ø Today’s CO2 concentration may be unprecedented in 800,000 years, but, notwithstanding the increase in anthropogenic emissions, to the nearest tenth of one per cent there is no CO2 in the air at all.

Ø In the Neoproterozoic era, 750 million years ago, the atmosphere was 30% CO2 and the planet did not fry.

Ø In the Cambrian era 550 million years ago the concentration was 20-25 times today’s.

Ø In the Jurassic era it was 12-15 times today’s. Yet here we all are.

Ø Mr Varley has mentioned only the theoretical harm that he imagines warmer weather may cause, without mentioning the many benefits of increased CO2 concentration, not least in increasing the net primary productivity of trees and plants worldwide by 2% per decade; increasing the yield of staple crops by up to 40% per CO2 doubling; and increasing the resistance of plants and crops to drought.

Ø Also, cold is a far worse killer than warmth. It is no accident that 90% of all species live in the tropics, and fewer than 1% at the Poles.

Ø Mr Varley says, “Scientists have calculated that more than half of the observed warming since the mid-20th century was caused by the increase in man-made greenhouse gases.” Certainly that is what the IPCC has long maintained. However, in this respect the IPCC is not honoring its obligation to reflect the peer-reviewed scientific literature.

Ø Though propagandists have sought to maintain that there is a “97% consensus” to the effect that recent global warming is mostly manmade, the truth – given in Legates et al.(2013) – is that only 0.3% of climate science papers published in the 21 years 1991-2011 stated that recent global warming was mostly manmade:



Ø The truth is that at present we are unable to distinguish between the respective magnitudes of the anthropogenic and natural components in the global warming that unaccountably stopped more than 18 years ago.

Ø In one sense, however, it might legitimately be said that global warming is manmade. For the terrestrial temperature records have been relentlessly and unidirectionally altered to make early-20th-century temperatures cooler and later temperatures warmer, in a manner calculated falsely and perhaps substantially to overstate the true warming rate in the 20th century:


Ø The NCDC’s adjustments are influential, because all three of the longest-standing terrestrial temperature records rely on its historical climate network for the compilation of their datasets. The changes made by the NCDC to the historical climate network data in just eight years are shown here:


Ø The tampering over the past seven years shows how earlier temperatures have been pushed ever lower and later temperatures pushed ever higher. There may or may not be legitimate reasons for this tampering, which always appears to go in the direction of amplifying Man’s influence on climate (the equivalent GISS “adjustment” is even larger than for NCDC), but it introduces an additional uncertainty to temperature measurements that Mr Varley’s article fails to reflect:


Are the computer models of climate reliable?

Mr Varley says:

“It is through models that we predict future climate, but not until they have been tried and tested to see how well they reproduce historic climate. Simulations of the future point towards further warming, and changes in all components of the climate system, including means and extremes of temperature, more intense and frequent rainfall events over many land areas, increases in sea level, and further ice melt.”

Again, here are some of the balancing considerations omitted by Mr Varley:

Ø First, the models have been “tried and tested”. They have failed. Anyone can re-tune them to match past climate. The real test is whether they can predict future climate. They cannot. In 1990 the IPCC predicted that the rate of global warming would be twice what has occurred in the 25 years since then:


Ø Secondly, the IPCC predicted in 2007 that there should have been significant global warming in the decade since 2005. However, there has been hardly any:


Ø Thirdly, the IPCC in 2007 and again in 2013 predicted short-term global warming, relying on the CMIP3 and CMIP5 computer models, but again the models’ predictions have proven excessive:


Ø Fourthly, the latest models continue to diverge ever farther from observation:


Ø Fifthly, models have also over-predicted regional warming, for instance in the tropics:


Ø Sixthly, warming at the North Pole has also been somewhat over-predicted:


Ø Seventhly, models can be tuned to fit the past but cannot predict the future:


Ø Eighthly, even the oldest weather organization in the world gets it wrong:


Ø Ninthly, even the earliest predictions were exaggerated, and it was on the basis of these exaggerations that urgent action on climate was demanded:


Ø Tenthly, models also over-predict ocean warming, and by a wide margin:


Ø The pre-final draft of the IPCC’s 2013 Fifth Assessment Report showed a graph demonstrating that all four previous Assessment Reports had flagrantly exaggerated their predictions of the increase in methane concentration. The observed trend falls below the prediction interval in all four previous Assessment Reports. However, at the insistence of Hungary and Germany, the graph was removed from the final report not because it was incorrect but because “it might give ammunition to sceptics”.


Ø Twelfthly, the models have been particularly bad at predicting temperature trends in the crucial tropical mid-troposphere about six miles up, and the IPCC’s self-confidence in models’ predictive skill increases as the gap between the models’ exaggerations and observed reality widens:


The IPCC has itself conceded that the models in which it once imprudently placed absolute faith have proven defective, at least in the medium term. In 2013 the IPCC admitted that 111 of 114 models had run hot, explicitly abandoned them, and substituted what it called its “expert assessment” for their output. The effect was dramatic: the IPCC all but halved its predictions of near-term warming:


The models, then, have not proven reliable. Though the chief executive of the Met Office might be forgiven for not mentioning as many failures by the models as have been illustrated here, no account of the supposed threat from global warming will be balanced unless it records that the models have erred, and have very nearly always erred on the side of considerable exaggeration of what may not after all be a threat.

Has climate science become dishonest?

The one-sidedness of Mr Varley’s article raises legitimate questions about whether those who profit from the vast sums paid by panicky governments to climate science are acting not only in a fair and balanced way but also in an honest way. There is evidence of unethical conduct by a small number of influential scientists promoting alarm that, on the evidence, is unjustifiable. Some examples of outright dishonesty will now be given. Mr Varley’s article contains no hint of this unethical conduct.

Ø The IPCC’s 1990 First Assessment Report had stated its “substantial confidence” in the models: yet the warming trend in the quarter-century since 1990 falls substantially below the entire interval that the IPCC had then predicted. Over-claiming certainty about what is uncertain is the central dishonesty in climate.

Ø The pre-final draft of the IPCC’s 1995 Second Assessment Report stated five times that evidence for human influence on climate was lacking, but the IPCC asked a single scientist to rewrite the report to remove all five references, replacing them with a single statement that a human influence on global climate was now discernible. The “consensus” is that of just one man:


Ø The front cover of the World Meteorological Organization’s 1999 State of the Global Climate report showed three attempted reconstructions of 1000 years’ temperature changes derived from tree rings (below left): however, from 1960 onward the true tree-ring data (white inset panel, below right) did not reflect the observed warming. The true data for one of the three (green, below right) showed a decline where thermometers showed an increase. To conceal these divergences, the WMO graph spliced the last 50 years’ measured warming (black, below right) on to the tree-ring data, but without disclosing that that was what had been done. All three tree-ring records were tampered with to conceal the splicing, making it appear that they matched real temperatures. In particular, the pronounced decline in the green tree-ring dataset, a decline that was directly contrary to measured global temperatures and hence establishing that tree-rings are not a suitable way to reconstruct past global temperature change, was eradicated:


Ø The “hockey-stick” reconstruction of the past 1000 years’ global temperatures in the IPCC’s 2001 Third Assessment Report (below right), visibly similar to the WMO’s graph,also purported to abolish the medieval warm period. The IPCC adopted this doctored graph as its logo until independent research showed it was a fabrication. Subsequently, the author of one of the three tree-ring datasets and of the hockey-stick graph denied under oath in court that he was an author of the WMO’s 1999 graph: yet his name appeared on the graph and in the acknowledgements on the inside front cover of the publication:


Ø The hockey-stick graph is inconsistent with empirical reconstructions in some 450 peer-reviewed papers. It is also inconsistent with the sea-level record, and with the previous understanding of the past 1000 years’ temperature change:


Ø The IPCC has refused to correct a major statistical error in its models. An influential graph in the IPCC’s 2007 Fourth Assessment Report showed the temperature record of the previous 155 years overlain by four linear trend lines starting 150, 100, 50 and 25 years previously (below). Each successive trend line was steeper than the last. The offending graph was displayed twice in the report, each time with the conclusion that the rate of global warming was accelerating and that humans were to blame. In fact, the slope of the 25-year trend line had two previous precedents in the temperature data (yellow arrows, below right), so there had been no acceleration in the warming rate. The fact that there has been no global warming for more than 18 years confirms the absence of any acceleration. The IPCC had used a false statistical technique:



Ø A sine-wave (above left) has a zero trend by definition, but the same false technique can be made to show that it has an apparently accelerating uptrend (above right). The IPCC refused to correct the error when one of its own reviewers complained to it.

Ø As noted earlier, there has been systemic tampering with the terrestrial temperature records so as arbitrarily to depress the true temperatures in the early 20th century and to elevate them at the end of the century in a manner calculated artificially to increase the apparent rate of global warming. The satellite records, however, are not so easily tampered with. Since they began in 1979, they show appreciably less warming than the much-altered terrestrial records. In April 2015, Professor Terence Kealey, former vice-chancellor of Buckingham University, announced an independent inquiry into the tampered terrestrial records.

Are floods and droughts worsening and crops failing as predicted?

Mr Varley says there are –

“… implications for flooding, drought, crop production, inundation of coastal communities, and threats to ecosystems unable to adapt quickly enough to the rapid rate of climate change.”

The balancing facts:

Ø CO2 is good for crops. Crop yields have grown with particular rapidity since 1950. There are three main reasons: improved agricultural practices, warmer weather, and CO2 fertilization (nearly all anthropogenic CO2 was emitted after 1950):


Ø Rising CO2 in the air causes a very rapid increase in combined crop yield:


Ø As for droughts, the area of the globe suffering drought conditions has declined throughout the past 35 years:


Ø As for “inundation of coastal communities”, sea level is not rising fast enough to make much difference globally: nor, on present trends, is it at all likely to do so.

Ø As for adaptation of species to “rapid climate change”, the conspicuous feature of the past two decades is the very slow – indeed, almost non-existent – rate of global warming. There is no evidence that the rate of global warming seen in the terrestrial and ocean datasets – equivalent to 0.25 Cº per century – will accelerate tenfold by 2100, as it would have to do to reach the IPCC’s central estimate of 21st-century global warming.

Ø Temperatures vary by as much as 100 Fº between midnight and midday in some places. The notion that species cannot adapt to a warming one-twentieth as big as this diurnal variation is ill founded – and the evidence to date indicates that no warming at that rate is at all likely.


The Met Office makes very large sums every year out of climate change. It is part of an international network of governmental and corporate interests that benefit greatly from giving a narrowly one-sided view of global warming science.

The wider range of scientific facts and results than that which Mr Varley chose to put forward surely demonstrates that – at the very least – there are two sides to the climate question. And it is equally surely the duty of the Met Office to take a neutral, fair and balanced scientific stance.

On the evidence here presented, Mr Varley has misled his readers by not presenting a balanced account of the state of global warming science. He is by no means unique. Profiteers of doom all over the world have taken advantage of the near-universal ignorance of science among politicians, press and public. That ignorance is costly, not only in treasure but also in lives. It is too often falsely claimed that climate change harms the poor. There has not been enough change to harm anyone, nor will there be. However, misguided policies to make the rich richer by addressing the non-problem that was global warming are already making the poor poorer still.

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