Prof Judith Curry (and others) on Climate Change
The leaks of the current draft of IPCC V report, possibly deliberately generated from IPCC HQ itself, have encouraged The Australian to “move forward” and publish today an analysis by highly respected American sceptic, Professor Judith Curry. Her article below does not reject the IPCC belief that, unless governments act to reduce usage of fossil fuels, there will be extensive damage to plants and animals (including humans), possibly extinction. But in what amounts to a summary of what she has been doing for some time now, she points to many uncertainties in the analyses published by the IPCC and calls for an end to the scientific consensus claims and an approach which identifies the uncertainties.
For the reasons outlined in my presentation of 19 September (which you should all have), I take the response to the IPCC considerably further than she does. I would only add here that the idea that any meaningful scientific consensus exists has long ere ceased to hold water.
My presentation referred to four highly respected Australian climate scientists who attempted to persuade the previous Climate Change minister to establish an independent inquiry into the so-called science. I also referred to the marked difference between the science and summary sections of the 2007 IPCC report. Thus whereas the science section included
the words “uncertain” or “uncertainty” more than 1,300 times (and included no less than 54 “key uncertainties” that acknowledged limits to capacity to predict climate change), this did not recur in the much shorter “Summary for Policy Makers”, which was clearly designed to “sell” the dangerous warming thesis to governments and the public without drawing attention to uncertainties.
In the United States many sources of scepticism have emerged, led by the privately financed Science and Environment Policy Project established by physicist former Professor Fred Singer and issuing an authoritative weekly critique. The Global Warming Policy Foundation headed by former UK Chancellor, Lord Lawson, is a major source of scepticism in the UK. In the American Physical Society, which is the top body of US physicists, a large dissenting group circulated a letter in 2010 arguing that ClimateGate had revealed “an international fraud, the worst any of us have seen”. Then in early 2011, after 18 warmist scientists sent a letter to US Congress asking that its attention be concentrated on the view that human activity is changing the climate, 36 scientists responded with a letter referring to 678 peer-reviewed scientific studies that “offer a point-by-point rebuttal of all the claims” by the 18. Also in the US, over 30,000 scientists, including 9,000 with Phds, have signed a petition specifically rejecting the dangerous warming thesis.
The nonsense written below in an article published in today’s The Australian by academic researcher Cook needs to be read against this background and in the light of what Dr Phillip Jones, the head of the Climate Research Unit at East Anglia University, a major source of advice to the IPCC, told the BBC in an interview in 2010. Jones then acknowledged that surface temperature data probably cannot be verified or replicated; that the medieval warming period may have been as warm as today; that no statistically measured global warming has occurred for the last 15 years; and that the science is not settled. In short even the experts are uncertain.
No doubt more claims and counter claims will emerge in the lead up to the publication of IPCC V on 27 September. Prof Curry refers to reports that the IPCC has been under pressure to “address the pause specifically”. It is possible that IPCC HQ responded by leaking the draft in order to publicise its then existing approach and obtain support from warmists before the final meeting is held from 23-24 September in Stockholm. We sceptics can only hope that the final is better than the draft.
Des Moore
Consensus distorts the climate picture
(Article by Judith Curry published in The Australian, 21 September 2013.)
IN February 2007, publication of the Intergovernmental Panel on Climate Change's Fourth Assessment Report (AR4) was received with international acclaim.
The vaunted IPCC process -- multitudes of experts from more than 100 countries examining thousands of refereed journal publications, with hundreds of expert reviewers, across a period of four years -- elevated the authority of the IPCC report to near biblical heights. Journalists jumped on board and even the oil and energy companies neared capitulation.
The veneration culminated with the Nobel Peace Prize, which the IPCC was awarded jointly with former US vice-president Al Gore. At the time, I joined the consensus in supporting this document as authoritative; I was convinced by the rigours of the process. Although I didn't agree with some statements in the document and had nagging concerns about the treatment of uncertainty, I bought into the meme of: "Don't trust what one scientist says; trust the consensus-building process of the IPCC experts."
Six-and-a-half years later, nominally a week before the release of the IPCC Fifth Assessment Report (AR5), substantial criticisms are being made of leaked versions of the report as well as of the IPCC process. IPCC insiders are bemoaning their loss of scientific and political influence. What happened to precipitate this change?
The IPCC was seriously tarnished by the unauthorised release of emails from the University of East Anglia in November 2009 that became known as the Climategate affair. These emails revealed the "sausage-making" involved in the IPCC's consensus-building process, including denial of data access to individuals who wanted to audit its data processing and scientific results, interference in the peer-review process to minimise the influence of sceptical criticisms and manipulation of the media.
Climategate was soon followed by the identification of an egregious error involving the melting of Himalayan glaciers. These revelations were made much worse by the response of the IPCC to these issues. Then came concerns about the behaviour of the IPCC's chairman Rajendra Pachauri and investigations of the infiltration of green advocacy groups into the IPCC. All of this was occurring against a background of explicit advocacy and activism by IPCC leaders related to carbon dioxide mitigation policies.
Although the scientists and institutions involved in Climategate were cleared of charges of scientific misconduct, the scientists and the IPCC did not seem to understand the cumulative impact of these events on the loss of trust in climate scientists and the IPCC process.
The IPCC's consensus-building process relies heavily on expert judgment; if the public and the policymakers no longer trust these particular experts, then we can expect a very different dynamic to be in play with regards to the reception of the AR5 relative to the release of the AR4 in 2007.
THERE is another, more vexing dilemma facing the IPCC, however. Since the publication of the AR4, nature has thrown the IPCC a curveball: there has been no significant increase in global average surface temperature for the past 15-plus years. This has been referred to as a pause or hiatus in global warming.
Almost all climate scientists agree on the physics of the infrared emission of the CO2 molecule and understand that if all other things remain equal, more CO2 in the atmosphere will have a warming effect on the planet. Further, almost all agree that the planet has warmed across the past century and that humans have had some impact on the climate.
But understanding the causes of recent climate change and predicting future change is far from a straightforward endeavour.
The heart of the debate surrounding the IPCC's AR5 is summarised by the graphic on this page that compares climate model projections of global average surface temperature anomalies against observations.
This diagram is Figure 1.4 from the first chapter of an AR5 draft. FAR denotes the First Assessment Report (1990), SAR the second (1995) and TAR the third (2001), which was followed by the AR4 (2007). It is seen that climate models have significantly over-predicted the warming effect of CO2 since 1990, a period during which CO2 concentrations increased from 335 parts per million to more than 400ppm.
The most recent climate model simulations used in the AR5 indicate that the warming stagnation since 1998 is no longer consistent with model projections even at the 2 per cent confidence level. Based on early drafts of the AR5, the IPCC seemed prepared to dismiss the pause as irrelevant noise associated with natural variability. Apparently the IPCC has been under pressure from reviewers and its policymaker constituency to address the pause specifically.
Here is the relevant text from the leaked final draft of the AR5 summary for policymakers: "Models do not generally reproduce the observed reduction in surface warming trend over the last 10-15 years.
"The observed reduction in warming trend over the period 1998-2012 as compared to the period 1951-2012 is due in roughly equal measure to a cooling contribution from internal variability and a reduced trend in radiative forcing (medium confidence).
"The reduced trend in radiative forcing is primarily due to volcanic eruptions and the downward phase of the current solar cycle. However, there is low confidence in quantifying the role of changes in radiative forcing in causing this reduced warming trend. There is medium confidence that this difference between models and observations is to a substantial degree caused by unpredictable climate variability, with possible contributions from inadequacies in the solar, volcanic and aerosol forcings used by the models and, in some models, from too strong a response to increasing greenhouse-gas forcing."
The IPCC acknowledges the pause and admits climate models do not reproduce the pause. I infer from these statements that the IPCC has failed to convincingly explain the pause in terms of external radiative forcing from greenhouse gases, aerosols, solar or volcanic forcing; this leaves natural internal variability as the predominant candidate to explain the pause.
Natural internal variability is associated with chaotic interactions between the atmosphere and ocean. The most familiar mode of natural internal variability is El Nino/La Nina. On longer multi-decadal time scales, there is a network of atmospheric and oceanic circulation regimes, including the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation.
The IPCC refers to this as "unpredictable climate variability" in its statement above.
My chain of reasoning leads me to conclude that the IPCC's estimates of the sensitivity of climate to greenhouse gas forcing are too high, raising serious questions about the confidence we can place in the IPCC's attribution of warming in the last quarter of the 20th century primarily to greenhouse gases, and also its projections of future warming. If the IPCC attributes the pause to natural internal variability, then this prompts the question as to what extent the warming between 1975 and 2000 can also be explained by natural internal variability.
Nevertheless, the IPCC concludes in the final AR5 draft of the summary for policymakers: "There is very high confidence that climate models reproduce the observed large-scale patterns and multi-decadal trends in surface temperature, especially since the mid-20th century.
"It is extremely likely that human influence on climate caused more than half of the observed increase in global average surface temperature from 1951-2010.
"Continued emissions of greenhouse gases would cause further warming. Emissions at or above current rates would induce changes in all components in the climate system, some of which would very likely be unprecedented in hundreds to thousands of years."
WHY is my reasoning about the implications of the pause, in terms of attribution of the late 20th-century warming and implications for future warming, so different from the conclusions drawn by the IPCC? The disagreement arises from different assessments of the value and importance of particular classes of evidence as well as disagreement about the appropriate logical framework for linking and assessing the evidence. My reasoning is weighted heavily in favour of observational evidence and understanding of natural internal variability of the climate system, whereas the IPCC's reasoning is weighted heavily in favour of climate model simulations and external forcing of climate change.
I do not expect my interpretation and analysis to be given credence above the IPCC consensus. Rather, I am arguing that the complexity of the problem, acknowledged uncertainties and suspected areas of ignorance indicate several different plausible interpretations of the evidence. Hence ascribing a high confidence level to either of these interpretations is not justified by the available evidence and our present understanding.
How to reason about uncertainties in the complex climate system and its computer simulations is neither simple nor obvious. Biases can abound when reasoning and making judgments about such a complex system, through excessive reliance on a particular piece of evidence, the presence of cognitive biases in heuristics, failure to account for indeterminacy and ignorance, and logical fallacies and errors including circular reasoning.
The politicisation of climate science is another source of bias, including explicit policy advocacy by some IPCC scientists. Further, the consensus-building process can be a source of bias. A strongly held prior belief can skew the total evidence that is available subsequently in a direction that is favourable to itself. The consensus-building process has been found to act generally in the direction of understating the uncertainty associated with a given outcome. Group decisions can be dominated by a single confident member.
Once the IPCC's consensus claim was made, scientists involved in the IPCC process had reasons to consider the possible effect of their subsequent statements on their ability to defend the consensus claim, and the impact of their statements on policymaking.
The climate community has worked for more than 20 years to establish a scientific consensus on anthropogenic climate change. The IPCC consensus-building process played a useful role in the early synthesis of the scientific knowledge. However, the ongoing scientific consensus-seeking process has had the unintended consequence of oversimplifying the problem and its solution and hyper-politicising both, introducing biases into the science and related decision-making processes.
SCIENTISTS do not need to be consensual to be authoritative. Authority rests in the credibility of the arguments, which must include explicit reflection on uncertainties, ambiguities and areas of ignorance, and more openness for dissent. The role of scientists should not be to develop political will to act by hiding or simplifying the uncertainties, explicitly or implicitly, behind a negotiated consensus. I have recommended that the scientific consensus-seeking process be abandoned in favour of a more traditional review that presents arguments for and against, discusses the uncertainties, and speculates on the known and unknown unknowns. I think such a process would support scientific progress far better and be more useful for policymakers.
The growing implications of the messy wickedness of the climate-change problem are becoming increasingly apparent, highlighting the inadequacies of the "consensus to power" approach for decision-making on such complex issues.
Let's abandon the scientific consensus-seeking approach in favour of open debate and discussion of a broad range of policy options that stimulate local and regional solutions to the multifaceted and interrelated issues surrounding climate change.
Judith Curry is a professor and chair of the school of earth and atmospheric sciences at the Georgia Institute of Technology in the US, and president of Climate Forecast Applications Network. She is proprietor of the blog Climate Etc.
Hardly any experts doubt human-caused climate change
(Article by John Cook published in The Australian, 21 September 2013.)
IN 2009, University of East Anglia servers were hacked, with years of private correspondence between climate scientists stolen. The hacker uploaded the emails to the internet, allowing bloggers to republish carefully selected quotes. During the next two years, nine investigations from university and government bodies on both sides of the Atlantic investigated the stolen emails. All unanimously found no evidence of data falsification. The sinister conspiracies conjured by the fevered imagination of the blogosphere failed to materialise.
The theft of the private emails, dubbed Climategate, demonstrates the fallacy of over-interpreting cherry-picked quotes from private conversations. A single quote cannot capture the full context of a conversation, let alone explain the nuances of the science. Climategate lends credence to the infamous saying by Cardinal Richelieu: "Give me six lines written by the most honest man in the world, and I will find enough in them to hang him."
In an article in Inquirer last week, Andrew Montford republished illegally obtained private correspondence, falling into the same fallacy of portraying an incomplete, misleading picture. Last year, my server was hacked and years of private conversations were stolen. Montford republished a quote in which I discussed reducing the public misperception about the scientific consensus on human-caused global warming. Montford argued from this quote that our research was a public relations exercise rather than a scientific investigation.
What is the bigger picture that Montford overlooks? To begin with, he fails to consider that we had already performed a great deal of scientific investigation, scanning more than 12,000 abstracts and determining that papers rejecting human-caused global warming had a vanishingly small presence in the peer-reviewed literature.
Preliminary analysis had already observed that the amount of research endorsing human-caused global warming was increasing at an accelerating rate.
Montford also fails to realise that a high-impact, peer-reviewed journal such as Environmental Research Letters publishes only research that makes a significant scholarly contribution. Our research analysed for the first time the evolution of scientific consensus across the past two decades. We found that scientific agreement strengthened as more evidence for human-caused global warming accumulated.
Another novel contribution of our research was inviting the authors of the papers to rate their own research. After all, who is more of an expert on a paper than its author? This independent approach produced a 97.2 per cent consensus on human-caused global warming, confirming the 97.1 per cent consensus we observed from the abstract text.
That 1200 scientists from across the world confirmed the overwhelming consensus is a fact studiously ignored by critics of our paper. The independent ratings by the paper's authors also expose the fallacy that we used an asymmetrical definition for consensus. We adopted several different definitions of consensus because scientists endorse human-caused global warming in different ways.
Some are explicit about how much humans have contributed. Others endorse the consensus without quantifying the human contribution. Others imply rather than explicitly endorse the consensus. The bottom line is no matter which definition you adopt, you always find an overwhelming consensus.
What if we only use symmetrical definitions of consensus; for example, humans are causing more than half of global warming versus less than half? Scientists who rated their own papers by these definitions show a consensus of 96.2 per cent.
Scientific agreement is so robust, you can look at it front-on, sideways or upside down and still find a consensus.
In fact, our research is not the only evidence for scientific consensus. A survey of earth scientists found 97 per cent consensus among actively publishing climate scientists. A compilation of public statements on climate change found 97 per cent consensus among published climate scientists. National academies of science from 80 countries endorse the consensus. Not a single academy of science disputes human-caused global warming.
Our research is the latest in a long line of statements and studies affirming that among the world's experts on climate change, it's considered a fundamental fact humans are causing global warming.
Despite this robust agreement, a "consensus gap" exists, with the public perceiving a 50:50 scientific debate. As well as provide scholarly contributions with our research, we set out to reduce this persistent public misperception. It is possible to do both at the same time.
Trying to reframe peer-reviewed research based on an out-of-context quote as a "PR exercise" is simply an attempt to avoid facing the facts.
John Cook is climate change communication research fellow at the Global Change Institute at the University of Queensland.
Warming in danger zone
(Article by Tom Arup, Environment Editor for The Age, 21 September 2013.)
Humans have already released half the total carbon dioxide emissions permissible before the planet is at risk of warming to dangerous levels, a draft United Nations scientific assessment says.
The final draft of a major assessment by the Intergovernmental Panel on Climate Change suggests that keeping warming to 2 degrees - regarded as a guard-rail against the worst impacts of climate change - will require deep global emissions cuts in coming decades.
Under the future emissions scenarios considered by the IPCC, only the most stringent would keep the world within the remaining CO2 allowance for 2 degrees. It would mean an average global emission cut of 50 per cent by mid-century on 1990 levels, and possibly require removal of carbon dioxide from the atmosphere by 2100.
Dr Malte Meinshausen, senior researcher at the Potsdam Institute for Climate Impact Research, said it also meant global emissions would need to fall to almost zero by 2070.
He said many studies showed it was technically and economically feasible. ''It is a question of political will whether the technologies that we have are implemented to the extent needed.''
Next Friday the IPCC will release the first part of its fifth global assessment of climate science in Stockholm. It was prepared over six years by hundreds of climate scientists.
The draft report lifts the IPCC's scientific certainty that human activity - such as burning fossil fuels - caused more than half the warming since the middle of last century to a 95 per cent confidence.
It also says warming has slowed in the past 15 years to 0.05 degrees a decade - below the long-term average of 0.12 degrees since 1951 - but the first 10 years of the 21st century were the warmest since 1850. All up, Earth's surface has warmed on average 0.89 degrees since 1901.
For the first time, the IPCC draft also includes an estimate of the total cumulative CO2 emissions that can be released since pre-industrial times to give the world above a 66 per cent chance of keeping warming below 2 degrees.
The draft estimates total human CO2 emissions need to be limited to about 3670 billion tonnes of carbon dioxide to keep below 2 degrees. By 2011, between 1688 and 2312 billion tonnes of CO2 had been released, about half the total allowance.
The budget does not take into account other planet-warming gases such as methane and nitrous oxide. Nor does it consider potential emissions from thawing permafrost or methane ice. ''If it is taken as a policy indication of where the carbon budget should be then we should certainly have to aim for something substantially lower than that because we have other greenhouse gases [than CO2],'' Dr Meinshausen said.
If the world proceeds along the highest future emissions path, a further 6183 billion tonnes of CO2 would be released by 2100, the draft says, meaning potential temperature rises of 2.6 to 4.8 degrees by century's end.
Environment Minister Greg Hunt would not comment on the IPCC report until it is released. But he was confident the world would deal with climate change.
"The reason I am most confident is because the Chinese and the Americans who are the central part of any agreement both have a very strong view," he said. "The most heartening development in the past two years has been China's growing commitment to action from its paramount leadership."
Testing the climate consensus
(Editorial, The Australian, 21 September 2013.)
CONSENSUS has its strengths and weaknesses. In politics it can sometimes be a useful model; in other spheres, not so. Until recently it was not a term we associated with science, where the testing of provable facts takes precedence. The fact, for instance, that Nicolaus Copernicus failed to win a public consensus during his lifetime did not alter the reality of his postulations that the Earth was not at the centre of the universe. Likewise, the Earth was a sphere long before the flat Earth consensus dissipated. In that seminal study on such matters, Monty Python's Life of Brian, the point is clarified. An idolising crowd is told they should not follow Brian as the Messiah, but think for themselves. "You're all individuals," Brian tells them. "Yes," the crowd responds in unison. "We are all individuals." Then a lone voice pipes up. "I'm not." In this case, the consensus was wrong; as was the dissenter.
The issue of climate change is a significant political, economic and environmental dilemma confronting our nation and the international community. At its heart is science. While we can engage in complex debates about the variety of mechanisms, technologies and practices that can be employed to deal with the issue, none of it makes perfect sense until we grasp the dimensions of the problem. And this is where science is pre-eminent. Yet, thanks largely to the Intergovernmental Panel on Climate Change, the debate has been centred not on scientific claim and counter-claim -- or scientific theory and measurable results -- but on what's referred to as the "scientific consensus". This is almost an oxymoron; to at least some extent, the two words don't belong in the same sentence.
This is not to say we should not act on the best available scientific information in an emerging field of cross-discipline science. But it does mean we need to consider other ways of arriving at the best possible conclusions. Judith Curry makes a powerful case in Inquirer to drop the consensus approach in favour of open debate about uncertainties and interrelated issues. The media could start by reporting the 15-year pause in global warming. Perhaps the public is mature enough to discuss the full range of possible explanations. Perhaps those associated with the axed climate commission, such as David Karoly and Will Steffen, should give it a go.
Don't sweat fickleness, it's sun's fault or something in the water
(Article by Graham Lloyd published in The Australian, 21 September 2013.)
TO explain the world's recent fickle temperature record, it's not surprising sceptics and mainstream climate scientists are searching in opposite directions.
While many scientists are looking to the oceans for answers, others are turning to the sky.
Many people claim a confirmed downturn in solar activity can help explain why surface temperatures on Earth have not risen as quickly as expected during the past decade or more.
Just as they believe a lack of solar activity during the Maunder Minimum in the 17th century explains the Little Ice Age, they argue weaker recent solar activity can explain the so-called pause.
But scientists argue there were many more factors than solar activity responsible for the mini ice age. And most are adamant that the power of the sun, or lack of it, has been fully accounted for in the modern climate stocktake.
As Judith Curry writes today in Inquirer, a draft of the upcoming fifth report by the Intergovernmental Panel on Climate Change says the observed reduction in the warming trend across the period 1998 to last year was due at least in part to the "downward phase of the current solar cycle".
Former chief climate commissioner Tim Flannery says: "The best information that we have is that the solar activity is factored into all the models."
Despite the denials, the instinctive belief many people have in the power of the sun has been hard to shake. It may be reflected in a waning mainstream interest in climate change in some parts of the world.
A British government-funded survey this week found the proportion of people who did not believe in climate change had more than quadrupled since 2005. Nineteen per cent of Britons now say they do not believe the world's climate is changing, up from only 4 per cent in 2005.
Flannery rejects any suggestion climate scientists have erred in not tackling head-on contentious issues such as the plateau in average global surface temperatures.
It is now widely acknowledged that average surface temperatures have remained largely steady - at a high level - for more than a decade. But according to Flannery, the hiatus is mostly a mirage.
"We have been able to explain the pause clearly, in that what we have seen, at least on the part of the atmosphere, is that it bounces around from year to year or decade to decade in terms of average temperature, but the oceans are much more steady," Flannery says.
"That is because about 90 per cent of the heat captured by the atmosphere ends up in the ocean and you only need to change that heat take-up (in the ocean) a little bit because the atmosphere is 500 times smaller than the ocean.
"With the atmosphere, we can see a bit of a pause; but when you ask is the Earth warming or not, you have to look at the atmosphere, the oceans and the rocks - and the answer is yes."
Eventually, however, scientists acknowledge the sun will get its way. According to research published in Britain's The Guardian newspaper, the planet eventually will warm so much it will become impossible for plants, animals and humans to survive. This will be as a consequence of the sun's natural life cycle and the orbit of the Earth.
Andrew Rushby, from the University of East Anglia, is quoted saying: "It will get progressively hotter and there's nothing we can do about it."
But Earth has some time left before the sun gets too hot. In work published in the journal Astrobiology, scientists calculate the big sweat will come in the next 1.75 billion to 3.25 billion years.