Archive for the ‘Computer Models’ Category
Explanatory note: Obama may highlight coal but, given that climate change and ocean acidification are consequences of pumping geospheric carbon* into the biosphere, the priority must be to eliminate the most carbon intensive sources first. That means phasing out tar sands and coal as soon as possible. Hence the title to this post.
*i.e. carbon that has been out of circulation within the biosphere for millions of years, which has given rise to atmospheric CO2 levels unprecedented in millions of years. It really is that simple.
In the run up to the United Nations Climate Change Conference COP 21 scheduled for December 2015, 24 of the UK’s foremost academic institutions, including the Geological Society have published a joint Climate Communiqué calling on national governments to take immediate action if they want to avert the serious risks posed by climate change. The document states that to tackle climate change, governments, including that of the UK, must seize the opportunity at climate talks in Paris in December to negotiate an agreement based on the latest scientific evidence. Pointing to that scientific evidence, the organisations say that if we are to have a reasonable chance of limiting global warming in this century to 2°C relative to the pre-industrial period, we must transition to a zero-carbon world by early in the second half of the century.
A feature-length documentary, based on the content of the Merchants of Doubt book by Naomi Oreskes and Erik Conway, went on general release at movie theatres in the USA this weekend.
As Desmogbog.com points out, it has already attracted the attention of an odd mixture of ideologically-motivated deniers of the reality of anthropogenic climate disruption.
I say “odd” because, as per the above link, those who prefer to see climate science as a conspiracy to raise taxes (and install worldwide Communist government via the united Nations, etc.) include both longstanding disputers of inconvenient science like Fred Singer (who questions whether the movie is defamatory) and self-confessed non-experts like James Delingpole.
Both of the above would have done well to watch a recent BBC Four (television) programme – Climate Change by Numbers. In contrast to just about every other programme about climate change that you might have seen, this one is presented by three mathematicians. A 30-second trailer is inserted below but, if you have not seen the full 74-minute programme (opens in a new window), I really would recommend it.
The programme focuses on three numbers:
— 0.85 Celsius – the rise in average global surface temperatures since the 1880s.
— 95% – the certainty of the scientific community that this is primarily human-caused.
— 1 trillion tonnes – humanity’s carbon budget to avoid 0.85 increasing to 2 Celsius.
Along the way, the programme highlights the early work of Svante Arrhenius – who determined that a halving of atmospheric CO2 could cause a 4 Celsius drop in temperature (and therefore that a doubling of CO2 will cause a 4 Celsius rise).
With regard to the accuracy of computer models, the programme highlights the way in which this has been proven by their ability to predict the cooling effects of large volcanic eruptions.
With regard to our carbon budget, the programme highlights the fact that humanity has already burnt 0.5 trillion tonnes and, unless radical changes are made to global trends, will burn the remaining 0.5 trillion tonnes within 30 years. It also points out that, as ongoing events might well suggest, even 2 Celsius could have severe and pervasive impacts (as the IPCC described them last year).
All very inconvenient for libertarians everywhere, I guess.
Addendum (17 March 2015):
The final third of the programme includes a discussion of ‘extreme value analysis’ (EVA), which Wikipedia helpfully describes as “a branch of statistics… [that] seeks to assess… the probability of events that are more extreme than any previously observed”. Flood defences like the Woolwich Barrier on the Thames estuary were designed using EVA. However, crucially, EVA assumes that average parameter values do not change over time. Therefore, given that climate change invalidates this assumption, it is now accepted that London will need greater protection from flooding in the future. This is why I included a link to (my blog post about) the ‘Climate Departure’ reseach of Mora et al. (i.e. below), which estimates the regional variation in the date by which future climates will have departed from what has hitherto been considered normal.
The video below contains a very compelling 22-minute summary of an impressive array of work, widely reported in the World’s newspapers this week. The research team, based in the Geography Department at the University of Hawaii, was led by Associate Professor Camilo Mora.
Sadly, it has already been dismissed by people with a track-record denying, downplaying or dismissing the nature, scale and urgency of the problem of anthropogenic climate disruption (ACD). People such as Bjorn Lomborg, for example.
A brief summary of the key points of the research:
1. For any geographic location the time of ‘climate departure’ is the time beyond which even the coldest monthly average temperature will be warmer than anything observed in the last 150 years. The same method was used to determine the time beyond which a range of other factors (such as precipitation and evaporation) would no longer fall below the range of local values observed in the last 150 years.
2. The monthly average data for all these calculations, data were obtained from 39 global climate models (GCMs – the accuracy of which I discuss below) constructed by 21 climate modelling centres in 12 different countries around the World. Common to all of these models is the same suite of CO2 emissions projections scenarios, two of which the research team used to define the range of possible temperature rises: RCP8.5 – representing a business as usual (BAU) scenario where humanity makes no attempt to reduce CO2 emissions; and RCP4.5 – representing a scenario where globally co-ordinated and concerted efforts are made to reduce CO2 emissions. With regard to atmospheric CO2 concentrations, it should be noted that:
— RCP8.5 is projected to result in a continuing increase to 900 ppm CO2 by the end of the Century; and
— RCP4.5 is projected to result in a peak value of 500 ppm being reached by mid-Century.
3. The results suggest that on average, climate departure (for temperature) is reached 2047 under the RCP8.5 scenario, or 2069 under the RCP4.5 scenario. This therefore implies that aggressive attempts to reduce carbon emissions could delay the onset of climate departure by several decades. Furthermore, the results suggest that climate departure will come to lower latitudes (equatorial and tropical areas) first. Under RCP8.5 this is as early as 2020 in some places. Under RCP4.5, climate departure is projected to be experienced almost everywhere by the end of the Century.
4. The team has produced an interactive map, published online here by the Washington Post newspaper, which can be used to see when climate departure is predicted under both scenarios for any location on the Earth’s surface.
5. The team suggests that the historical focus on absolute changes in temperature (i.e. predicted and observed to be greatest in polar regions) have given humans a false sense of security about the likely personal impacts. This study inverts that pattern and shatters the illusion that humans will not be directly impacted by changes in temperature. This is because, where the natural climate variability is smallest, less absolute change is required for it to be significant and most of the species present have less resilience to that change.
6. The research highlights the changes that have already occurred. Indeed, the most striking finding of the research is that the pH of seawater across the entire planet – i.e. without any exceptions – is already lower than it has been at any time in the last 150 years.
7. The research highlights the fact that those areas that are likely to reach climate departure soonest are also areas with the highest average population density and the lowest capacity to adapt. Under RCP4.5, it is expected that 1 billion people will be living in area experiencing unprecedented climatic conditions by 2050. Whereas, under the RCP8.5 this is expected to be 5 billion people (i.e. half the currently-projected global population).
8. The research indicates that the Earth’s most significant biological assets (essential ecosystem services and biodiversity) are at risk. This is the consequence of three facets of the above: (a) equatorial and tropical regions will be the first to experience climate departure; (b) they contain the greatest proportion of the Earth’s biological assets; and (c) are the least resilient to any change and the least able to adapt.
Conclusions (some readers may find some sentences upsetting)
1. If we stick to BAU, we will guarantee that (a) the long-term consequences will be increasingly unpleasant; (b) mitigation will become impossible; and (c) adaptation will be required sooner and faster and therefore be more costly. Alternatively, if we decide to try and mitigate ACD (by aggressively reducing CO2 emissions), we may be able to limit the unpleasantness and the scale and total cost of adaptation required (by humans and non-humans alike).
2. If we do nothing, the extinction of a significant proportion of species on Earth would appear to be unavoidable in the long-term (and, if that happens, the survival of humanity would have to be seriously in jeopardy). Alternatively, if we take action, the extinction of some species looks highly probable but, critically, this will buy most species several decades to adapt. This means that the costs of adaptation can be spread over those extra decades.
3. Given all of the above, how can it make any sense to continue to argue about what we should do?
Comments about the accuracy of Global Climate Models (GCMs)
One very easy way to dismiss all this is to point out that, in the course of the last decade, global average temperatures have slipped from well above 75th to just above 5th percentile of GCM predictions. Despite this, however, the exponential nature of the observed temperature increase over the last 150 years is very obvious in the above video.
Furthermore, the only way anyone can justify reaching the conclusion that this increase will not continue is by asserting that CO2 is not the main driver. A recent article on the Yale Forum on Climate Change and the Media website, entitled ‘Examining the Recent Slow-Down in Global Warming‘, has an excellent set of graphs that explain how and why we can be certain that CO2 is the main driver.
In addition, as per the comments I have posted on the above article, none of the GCMs include the global dimming effects of industrial pollution. Given that this is the case, I really do not understand why so many climate scientists keep saying we do not understand the reason for the current hiatus. In his book, ‘Storms of my Grandchildren’, James Hansen repeatedly complains about the fact that, 20 years ago, NASA refused to invest in satellite monitoring of this pollution. Thus we have been unable to model its effects because we have no data to put into the GCMs.
I am grateful to Schalke Cloete, of One in a Billion blog fame, for alerting me to this public debate, which was held on Monday at the privately-financed Duke University, in Durham, North Carolina (the US State that has passed a Law that makes accelerating sea level rise illegal).
The debate appears to have been arranged at the behest of one of the two protagonists, Alex Epstein (founder of the Center for Industrial Progress) – whose challenge Bill McKibben (350.org) clearly accepted.
The video below runs to nearly 100 minutes in length so, I suspect, only very few will watch it. Anyone who does will find it very rewarding but, for the majority that probably will not watch it, I have summarised its content below.
To start with both speakers are given 10 minutes to put their case, they are then given opportunity to respond to the points made by the other; to cross-examine each other; and to put forward closing arguments.
Bill McKibben went first and started by stating that fossil fuels were good for us but that the advantages of their continued use are now outweighed by the disadvantages and, therefore, wherever we can, we should stop using them. He then provided fact-based evidence for twelve risks we face if we do not do this:
1. Ocean acidification which will kill corals and endanger a wide variety of shellfish.
2. Melting Ice caps and permafrost (sea level rise and methane release).
3. Increasing frequency and severity of extreme weather events of all kinds.
4. Reduced crop for crops of all kinds and consequential increases in food prices.
5. Mass extinction of species (that cannot migrate or whose habitats are degraded).
6. Inundation of coastal cities (with all the collateral damage and disruption that will cause).
7. Increased frequency and severity of forest fires.
8. Increasing numbers of deaths resulting from atmospheric pollution and heat waves.
9. Economic growth and development will be hindered by increased expenditure on mitigation.
10. Socio-political instability and insecurity arising from all of the above (see the Pentagon’s QDR).
11. Libertarian desires will be endangered by the increasing need for autocratic responses.
12. Democracy itself is endangered by policy inaction being promoted by the fossil fuel lobby.
In response to all of this, Alex Epstein insisted that the risks were unproven. This being North Carolina (where accelerating sea level rise has been outlawed), he insisted that there is no evidence that things will get that bad. He then proceeded to point out that climate-related deaths (whatever they are) have gone down over time, whilst CO2 levels have gone up. Despite the fact that he did not himself offer any evidence, he dismissed all of McKibben’s well-referenced arguments as mere speculation. He then trotted out numerous climate denial classics including the mutually contradictory arguments that (a) global warming has stopped and (b) technology will enable us to solve the problem. Alex repeatedly referred to fossil fuels as affordable abundant energy; and repeatedly referred to it as real energy (implying that somehow renewable energy is not real?)
Bill McKibben responded to all of this by pointing out that correlation is not proof of causation; and provided yet more evidence to back up his original assertions. He questioned why anyone would champion increased fuel use rather than promoting the reduction of demand through improved energy efficiency. He questioned why Epstein was so defeatist about the prospects for renewable energy; and pointed out that many of the problems he cited had in fact already been solved. Renewable energy is real energy and, since the alternatives to fossil fuel exist, its use should therefore be maximised as fast as possible.
Epstein responded by asserting that all environmentalists are anti-progress because they are anti –hydroelectric projects and anti-nuclear. He therefore challenged McKibben to endorse the legitimacy of both as potential solutions. He then trotted out yet more climate change denial classics such as (i) CO2 is a trace gas (citing the rise from 0.03% volume to 0.04% volume as insignificant – even though that would actually represent a 33% increase); and (ii) climate model predictions have proven to be unreliable (when in fact they have proven to be overly optimistic). Despite the fact that Epstein – Philosophy and Computer Science major – is clearly no expert in the natural sciences, he even tried and failed to refute the fact that ocean acidification is not happening (by claiming they are becoming less alkaline and more neutral).
Epstein was then invited to rebut McKibben’s arguments. In so doing he repeated his mantra about the folly of giving up on the most affordable and abundant energy source we have, which would prevent progress; and unnecessarily condemn millions to a life of misery. He asserted that fossil fuels had made modern agriculture possible and solved the problem of world hunger that people worried about 40 years ago. Furthermore, given the growth in human population since then, he suggested that we now need fossil fuels in order to prevent widespread malnutrition and starvation.
In rebutting Epstein’s arguments, McKibben started by repeating that fossil fuels had made many good things possible in the past but that the risks of their continued use now outweigh the disadvantages. Climate change has already resulted in more food being eaten than grown in 6 of the last 11 years; and that unabated increase in fossil fuel use will only make it increasingly hard to grow crops. McKibben also questioned the wisdom of trying to refute the opinions of the World’s leading ecologists by asserting that our oceans are not actually turning into acids.
In their closing speeches, Epstein and McKibben recapped their main arguments: Epstein questioned the validity of all the evidence McKibben had presented (but presented none himself); and questioned the integrity of McKibben – accusing him of misrepresenting the situation (for what motive?). In complete contrast, McKibben did not use such language and, being careful not to attack Epstein personally, repeated his main point that the fossil fuel industry is the only one that does not pay to dispose of its waste. He then concluded by suggesting that fossil fuel companies need to decide to become energy companies instead; and embrace the use of all the alternatives that we have.
James Delingpole is almost as difficult to engage in debate as Lord Monckton; but not quite – at least I have had several exchanges of emails with Monckton. His Lordship may be equally as fond of facile sarcasm but at least he keeps up a pretence of being capable of debate. Delingpole is just sarcastic; and will not engage in debate with anyone who understands the science – let alone an actual climate scientist. But after being intellectually raped by Sir Paul Nurse, who can blame him? Still, I do wish he would shut up… This is a transcript of my latest attempt to get his attention (still visible here on his personal blog). However, he seems to be too busy over on his Telegraph blog debating the significance of more important political questions of our times such as: Has George Osborn has ever eaten a Cornish Pasty?…
I know you will cite the Met Office as being part of some anti-libertarian plot to install worldwide Socialist governance but, will you please do us all a favour and suspend your belief in conspiracy theories just long enough to take on board some new information:
“A project running almost 10,000 climate simulations on volunteers’ home computers has found that a global warming of 3 degrees Celsius by 2050 is ‘equally plausible’ as a rise of 1.4 degrees. The study addresses some of the uncertainties that previous forecasts, using simpler models or only a few dozen simulations, may have over-looked. Importantly, the forecast range is derived from using a complex Met Office model that accurately reproduces observed temperature changes over the last 50 years. The results suggest that the world is very likely to cross the ’2 degrees barrier’ at some point this century if emissions continue unabated. It also suggests that those planning for the impacts of climate change need to consider the possibility of warming of up to 3 degrees (above the 1961-1990 average) by 2050, even on a mid-range emission scenario. This is a faster rate of warming than most other models predict.”
Citizen science looks at future warming uncertainty.
N.B. The ability of these computer models to recreate historical trends over the last 50 years is not evidence of fudge factors having been applied: It is evidence of model validation, which – along with calibration and sensitivity analysis – is an integral part of establishing the accuracy of such modelling techniques. You can – or should – trust me on this because, unlike you, this is what I have been doing for the last 20 years or so (i.e. using probabilistic computer modelling in environmental risk assessments).
Your beloved marketplace of ideas is a dangerous fallacy; of which your success in getting your ill-informed unscientific opinions plastered all over the media and infecting people’s minds is profound evidence. And for what purpose? You may think you are acting in the public interest but, unfortunately, like everything else in Watermelons 2.0, this is an inversion of reality: As Peter Jacques (University of Florida) has pointed out, it is precisely because environmental scepticism is not in the public interest, the tobacco industry invented the sound science versus junk science debate (now being used to great effect by the fossil fuel and energy industry) to confuse people and prevent sensible regulation of their product.
Further to my somewhat over-long email to Professor Richard Lindzen on 23 February (on which yesterday’s post was based), and as a result of the subsequent exchange of emails between us, I extracted the key 17 questions buried in the original email; and turned them into 17 assertions that can either be accepted or disputed. This was sent to Professor Lindzen on 25 February 2012.
While waiting for Professor Lindzen to clarify his position, all readers are invited to see how many they are willing to concede may very well reflect reality:
1. The IPCC is too optimistic.
2. Holocene climatic stability is now endangered.
3. The ‘marketplace of ideas’ is a fallacy.
4. The notion of a scientific conspiracy is an illusion.
5. Some of your (Lindzen’s) graphs were potentially misleading.
6. Given (2), post-Industrial temperature rise is significant.
7. Given the inertia in the system, more warming is ‘in the pipeline’.
8. Sceptics are always ‘going down the up escalator’.
9. Therefore ‘global warming’ did not stop in 1998 (or at any other time).
10. Neither the Sun nor volcanoes are now the dominant climate forcing.
11. As CO2 is the only thing to have changed significantly, this is a ‘fair test’.
12. ACD is inevitable because the Earth’s energy balance must be restored.
13. Soon we will have to re-name the Glacier National Park in Montana.
14. It would be sensible to move to a low/zero carbon economy ASAP.
15. Environmental concern is based on palaeoclimatology not models.
16. Climate “sceptics” are not like Galileo.
17. Environmentalism is not the enemy of humanity.
How highly did you score?
There is one crucially-important factor (not stated as a question in the orginal email) – and that is Climate Sensitivity. If Professor lindzen is wrong, I think we’re all screwed… Unfortunately, just about every other legitimate climate scientist – apart from Judith Curry, Pat Michaels and Roy Spencer – thinks Professor Lindzen is indeed wrong.
So the big question is, what are we all going to do about it?
***UPDATE: Please make sure you read this too (and/or instead)!***
Last week, I was fortunate enough to get a ticket to a meeting in the Palace of Westminster at which MIT Professor Richard Lindzen was the guest speaker. Unfortunately, as a result of frustration with what I saw as Lindzen’s failure to explain the relevance of palaeoclimatology to our understanding of the way in which the Earth regulates its temperature, I blew my chance to ask a question. However, Prof. Lindzen kindly invited me to email them to him instead. I know it was a bit cheeky of me but, rather than email him the 3 questions I had prepared, I decided to email him questions arising from what he actually said instead. What follows is a copy of my rather long (whose fault is that?) email (I sent to him the next day) – only very slightly amended as a consequence of a subsequent exchange of emails (in which he did not answer any of my questions)…
***UPDATE: Because this is such a long post you may wish to skip ahead and come back later (may be). If so, go to this simple 17 sentence summary first or instead!***
Dear Professor Lindzen,
RE: My questions arising from listening to your talk entitled ‘Global Warming: How to Approach the Science (Climate models and the evidence)’, at the Palace of Westminster on Wednesday 22 February 2012
Given Viscount Monckton’s curtailment of our discussion, I am grateful to you for offering to answer my questions via email. I trust you have (had) a safe journey back to the USA.
In order that you may appreciate where I am coming from on this subject, please note that I am 47 years old and have over 25 years of professional work experience as a mine geologist and hydrogeologist; mostly having worked in environmental consultancy but also for the Environment Agency (the equivalent of your EPA). However, in addition to a BSc in Geology and an MSc in Hydrogeology, I now have an MA in Environmental Politics. (For more background on me, please see the ‘About’ page of my blog). In addition to my academic qualifications, I am a Fellow of the Geological Society of London (GSL) and a Chartered Geologist and, although I do not speak for the GSL (which can and does speak for itself – as does the American Association of Petroleum Geologists (AAPG)), I am copying this email to GSL Vice-President Professor Colin Summerhayes (who also asked you the question about the Palaeocene Eocene Thermal Maximum [PETM] at the meeting).
As you might imagine, I had come to the meeting with 3 questions prepared in the hope that I might get to ask at least one. Unfortunately, I never got as far as my first question (and was not allowed a second attempt)… However, given that the moment has now passed, I have decided that it would make more sense to pose my questions to you as they arise from the notes I made while you were talking. This email is therefore rather long but, even if it takes you a while (given all your other commitments), I hope you will be willing and able to respond in due course (e.g. please feel free to insert your responses in a distinctive font colour and return my email).
I hope you will not be offended but, I must confess to being somewhat surprised that your talk was not significantly different from the version on the Internet (i.e. as delivered 21 months ago at the ICCC4 in May 2010). In addition, although perfectly polite, I was disappointed by your seemingly repeated insinuation that the IPCC is a politically alarmist institution and/or that just about anyone that disagrees with you (e.g. Martin Rees and Ralph Cicerone) is part of some kind of global conspiracy to foist environmental alarmism on a credulous world; presumably for reasons of personal (scientific) or political expediency. You will gather from all this that I do not buy-in to the assertion that Climategate was anything other than a mendacious attempt to discredit climate science and scientists, which was all the more obvious after its repetition last year.
Therefore, although I am not questioning whether you believe what you say to be true (as that would be to question your integrity and/or intellectual honesty); I am bound to ask – where is the actual evidence for this? Furthermore, I am also bound to say that, on the contrary, there is very clear historical documentary evidence for an extensive, business-led, campaign to downplay, deny or dismiss a whole sequence of environmental problems over recent decades (e.g. see Merchants of Doubt). It is because of this that, despite what I consider to be my sound grasp of the physical basis for concern over anthropogenic climate disruption (ACD), my Lack of Environment blog tends to focus on the politics underlying its denial – and the denial of all other environmental problems (e.g. your previous advocacy work for and on behalf of the tobacco industry). However, I digress… As promised, here are my thoughts regarding your presentation:
In addition to the foregoing, I would make one further observation regarding your criticism of the IPCC: As you must know from first-hand experience, by virtue of the way the IPCC was set-up by UN-member governments, all of its reports are subject to line-by-line and word-by-word scrutiny; such that everything it has ever published has tended to be optimistic, under-stated and/or couched in vague and convoluted caveats. Furthermore, I should hope that you would also acknowledge that its AR4 documents (2007) are also now out-of-date?
In essence, your optimism appears to be founded upon your conviction that climate sensitivity is low. However, the fact remains that the last time the Earth experienced 450ppm of atmospheric CO2 (a level that we now seem certain to exceed) was 35 million years ago when global average temperatures were 4 Celsius warmer than prior to the Industrial Revolution; at which time Antarctica was ice-free. Furthermore, all existing life on Earth is adapted to the way things are now. Therefore, it is utterly irrelevant that it may have been significantly warmer in the more distant past. Do I really have to remind you that modern humans (cities, cultivation and civilisation) would not be here if it were not for the fact that both climate and sea levels have been remarkably stable for at least 7,000 years?
You expressed surprise at the fact that academics choose to be alarmed; whereas the public are sceptical. This seems a remarkable piece of reality inversion to me; and makes me wonder who you would consult if you were concerned that you might have a serious life-threatening medical condition? Surely the public’s scepticism and/or cynicism owes more to belief in ‘the marketplace of ideas’ and the modern preference for believing in conspiracy theories that absolve us of responsibility – and/or blame somebody else – for bad things that happen?
I was somewhat surprised at your criticism of the 255 National Academy of Sciences (NAS) signatories to a letter in Nature and the Guardian newspaper in May 2010 (i.e. that many were not actively involved in climate science) because you are the only climate scientist amongst sixteen signatories to a letter that appeared recently in the WSJ (which also refused to publish one signed by 255 relevant academics). Surely, then, it is hypocritical of you to criticise the NAS letter?
One of the many graphs you displayed showed at least a 0.6 Celsius rise since 1860 (although Richard Muller’s BEST study would suggest (as have many others before) that the increase is more than this). However, despite the relative climate and sea level stability over the last 7,000 years, you dismissed this as not “statistically significant”. Can you tell me at what point you would consider a rise to be statistically significant; and why? Are you not worried at all by the fact that, due to the massive inertia in the climate system, more warming is already “in the pipeline”?
You also criticised the dubious practice of manipulating the axes of graphs to misrepresent data and/or convey misleading ideas. However, at least one of your graphs did exactly that (i.e. steeply inclined Keeling Curve superimposed on cherry-picked slightly-declining, temperature gradient) [see important Footnote]. I would therefore agree with you, as the use of such tactics is clearly capable of suggesting that there is no correlation between two variables that are very well correlated indeed. Furthermore, I would be interested to know what your reaction is to the ‘Still Going Down the Up Escalator’ article on the SkepticalScience Website? Will you at least admit that Global Warming did not stop in 1998?
You mentioned in your talk that the Sun was 20% dimmer 2000 Ma BP and that the Earth was much colder back then (i.e. ‘Snowball Earth’). However, it has been much warmer in the past as well. This would appear to demonstrate that the Sun is not a dominant cause of current warming. Furthermore, the USGS have recently confirmed that volcanoes are not either. Despite your misgivings about use of the word “incontrovertible”, would you accept these assertions as at least highly likely to be true?
Although not the strongest greenhouse gas (GHG), CO2 is the most abundant, long-lived, GHG there is (i.e. water vapour is much more abundant but comes and goes; whereas methane is 23 times more powerful as a GHG but is much less abundant). Furthermore, CO2 is the only thing capable of explaining the warming we have seen over the last 150 years, because CO2 is the only thing that has changed significantly (i.e. increased by 40%) in that time. Surely this is what is known in science as a “fair test”? Nothing else has changed significantly (not the Sun, not cosmic rays, not water vapour, not volcanic eruptions). Given all of the above, can you please explain to me why you continue to assert that the science behind concern over the enhanced greenhouse effect is uncertain?
Towards the end of your talk, you mocked the alarmism of the 1920s. However, it was about that time that the first photographic records were made of glaciers in the Himalayas and elsewhere. Recent similar expeditions have proved that very significant loss of glacier ice-mass (i.e. depth and length) has occurred in 90 years and, in the case of South Georgia (i.e. the UK territory in the South Atlantic!) it is known that most of the retreat has occurred in the last 30 years. Furthermore, as an example closer to your home, it is currently estimated that in Montana, Glacier National Park has already lost over 75% of the 150 glaciers first observed (by Europeans) in the 1880s and, even at current rates of melting, they are all expected to have disappeared by 2030. At what stage do you think the National Park should be re-named? Would it not be a good idea for humanity to collectively agree to try and stop this happening elsewhere by moving rapidly to a low/zero carbon economy?
Finally, for the record, the 3 questions I had prepared (to which I would still also be delighted to receive answers), are as follows:
Concern over anthropogenic climate disruption (ACD) is based on the study of palaeoclimatology, not on computer modelling. However, models have helped to predict the atmospheric response to greenhouse gas emissions; and any uncertainties in model predictions have been due to uncertainties in emissions projections. Therefore, when reviewed retrospectively (choosing the most appropriate emissions scenario that reflects what actually happened to emissions), the models are demonstrably very accurate (if they include all climate forcings). Given all of this, why is it that you maintain that we have no reason to be concerned?
What is your answer to Utah-based Professor of Geological Sciences, Barry Bickmore, who recently suggested that today’s so-called climate “sceptics” are not like Galileo because, rather than fighting against one, they are fighting for an obscurantist and anti-intellectual Establishment, in an attempt to perpetuate the burning of fossil fuels for as long as possible?
Given the findings documented in Naomi Oreskes and Erik Conway’s book, Merchants of Doubt, can you please tell me why, having fought for so long on behalf of the tobacco industry to prevent legislation to minimise the harmful effects of smoking, you have apparently focused instead on helping the fossil fuel lobby deny that anthropogenic climate disruption is happening?
At 28 mins and 30 seconds into this video of the talk, it can be clearly seen that Lindzen presented a slide with the steeply inclined Keeling ‘curve’ overlain with static or slightly-declining recent temperature data. This slide does not appear in the published PDF of this presentation. Why is this?
For the avoidance of any doubt about this, here is a screenshot of the “missing” slide as it appears in the video: