THE CHERRY PICK

April 5th, 2007 <-- by Paul Higgins -->

Thousands of research papers have been published on different aspects of the science of climate change. Developing an accurate picture of the state of scientific knowledge requires sorting through and assessing the potential insights offered by these papers.

That’s what comprehensive assessments, like the Working Group I contribution to the IPCC’s most recent summarized and full reports and the National Academy of Sciences reports attempt to do. The credibility of these efforts is built on the inclusion of a broad range of independent experts, representation of the full range of credible scientific research, and an openness of the process and the participants to reassessment of their views in the face of new or contradictory evidence. The result is our most accurate depiction of what is known and not known about the state of climate science.

It remains possible, however, to select a relatively small handful of papers from among the many thousands in a way that presents a vastly different picture of the state of scientific understanding. This type of cherry picking isn’t very effective for arguments within the research community because scientists draw on the larger body of knowledge when assessing the merit of individual papers or the arguments that rest upon them. Cherry picking can be highly effective in misleading non-experts such as politicians, journalists, and the public, however.

It is important to realize that not all papers carry equal weight. Some papers have been more fully vetted by the research community and some results more widely reproduced. Different journals can have higher or lower standards for the work that they publish. Developing an accurate assessment of scientific knowledge requires distinguishing among conclusions that can be valid, invalid, or somewhere in between.

Is it ever appropriate to select individual papers that disagree with the conventional wisdom? Definitely! Sometimes a paper can be ground breaking. Sometimes a single paper conflicts with what we thought we knew and holds up after further scrutiny. But it is highly unusual for a paper to invalidate all the insights of previous research.

Instead, new research usually makes incremental contributions to our knowledge or provides a glimpse of new understanding that will only unfold fully through careful additional research efforts. Since some papers can be more credible than others and since some more weight than others, rejecting some and emphasizing others can make sense. How can we do that wisely? We conduct a careful and inclusive assessment.

The claim that one paper, or even a handful of disparate papers, undercut a comprehensive scientific assessment such as those by the IPCC or the National Academy of Sciences is dubious. Individual papers simply don’t carry the same weight as a broadly inclusive and comprehensive assessment process.

For this reason, appeals to individual papers, particularly those that supposedly disprove the findings of comprehensive assessments, should be looked at with skepticism.

4 Responses to “THE CHERRY PICK”

  1. Jim Clarke Says:

    There is only one reason to agree with this argument presented by Dr. Paul Higgins; it is the easiest thing to do. It is easy to rely on a consensus view as opposed to actually thinking about the pros and cons of a thoughtful argument. It is easy to dismiss dissenting views by claiming that the theoretical majority has spoken, as opposed to considering another view that, if true, threatens your livelihood. While it is easy, it is the opposite of being scientific.

    Of course, Dr. Higgins argument is not even based on a valid assumption. The IPCC documents and reports from the National Academy of Sciences are not ‘comprehensive assessments’ of the science, but sophisticated ‘cherry-picks’ all their own. They are the results of the ‘herd mentality’ in science that systematically stifles and chokes off dissenting views, even if those views are well-founded and supported by the available data. In the process of developing these assessments, countless valid interpretations of the data are discarded in favor of those interpretations that support the preordained assumptions of the scientific hierarchy.

    The most obvious example is the immediate adoption of the ‘Hockey Stick’ in the previous IPCC assessment. It does not matter if you think the hockey stick interpretation of past climate is an important climate change topic or not. The point is that it was not in line with the majority of paleoclimate studies that preceded or followed it, yet was immediately embraced (cherry-picked) by the ‘assessment process’ described above. The community then defended it well beyond what was scientifically reasonable, and now just doesn’t even want to talk about it.

    There are many other examples of cherry picking in these assessments, including the elimination of a complex solar/atmospheric relationship by artificially diminishing all solar affects to ‘irradiance’, the refusal to consider the affect of multi decadal ocean cycles on recent climate change and the highly selective use of aerosol data/theory to force fit the CO2 hypothesis into matching observations.

    None of this should be surprising, however, because all of these behaviors are right in line with human nature. Scientists of today are no less immune to peer pressure, politics and funding requirements, than scientists in the past. In fact, they are likely more influenced by these pressures than ever before, due to the near instantaneous communication of these forces through the community. While these pressures are understandable, they are not scientific in nature and work against the scientific process.

    Ultimately, the value of any scientific work is found in how well it explains the natural world around us, not how well it adheres to some artificial human construct. As scientists, we should judge the work of others on the strength of their argument, not on the name of the authors, the prestige of the journal or the number of other scientists who agree or disagree. It is only the strength of the argument that should persuade us one way or another.

    Einstein had it exactly right when confronted with the fact that the vast majority of scientists in his field disagreed with him, stating “It only takes one of them to prove me wrong!” If the arguments of those who disagree with the assessments, in part or in total, are so wrong, then it should be easy for one person to prove them wrong. Yet, when pounding away at opposing viewpoints, the club of choice over the last 15 years has been the appeal to authority/consensus, quickly followed by the ad hominem attack. This alone should give us pause!

    Yes, it is much easier to do as Dr. Higgins suggests, but it is not very scientific!

    [Response: Jim, thanks for taking the time to comment and share your views. At first look, it would seem that we don’t agree on much. With a closer look I think that we actually agree a lot, however, particularly on the most substantive and overarching issues that you mention. It is over the finer details that we don’t seem to see eye to eye. In the hopes of moving forward without sending the discussion way off topic or to unproductive areas, I’ll focus on the broad issues you raise and leave most of the fine details for another time or other places.

    First, let me emphasize that I strongly agree with your views that 1) the strength of scientific evidence and not the source (the researchers who do the work, the journal that publishes, time of publication, or the funding source) matters most, and 2) that any good assessment of scientific understanding must account for all the relevant evidence. To be a good scientist, one must always be open to new and contradictory evidence and be willing to reassess views based on it.

    I suspect that we can also agree that not all research results are equal. Some studies are done more carefully than others, some studies get reproduced by independent groups, some studies—particularly when they are surprising or have big implications—get more careful scrutiny. While assessments of science cannot dismiss results from papers because they don’t fit with expectations, papers that are flawed, don’t hold up to scrutiny, or otherwise offer limited insights on the world should rightly be left out (or be incorporated only to the extent that they contribute to our knowledge and understanding).

    The key question is how do we sift through all the available research and determine what is credible and insightful and what offers more limited insight or none at all?

    The best way that I can think of is to bring together the leading experts (i.e., those who know and understand the science the most) to assess the full body of research. In that process dissenting voices must be welcomed and accounted for (as they are by IPCC and NAS). Participants must be willing to reassess their views in the face of new evidence. Ideally, outside experts from similar but unrelated fields can help ensure that the process remains scientifically fair and credible (NAS does this).

    In your remarks, you suggest that scientists participating in the IPCC or NAS assessments suffer from a mob mentality. To me that just doesn’t fit. Groups of scientists rarely sit around agreeing with each other. Rather they voice their own views independently. These are individuals who often have different experiences and who come from a wide range of research areas. They disagree with one another all the time. Furthermore, one who simply goes along would not make an independent contribution to science and would therefore not be successful professionally.

    Keep in mind also that professional credibility for scientists rests on being accurate. By presenting a skewed or indefensible picture of what is known, a scientist would lose credibility and potentially suffer serious professional consequences. At a minimum, to ignore evidence that proves you’re wrong means that you’ll soon look like a fool when that evidence comes to light (as it inevitably will).

    This brings me to your Einstein quote, which I like very much and agree with. I don’t think you apply it fully or to everyone, however. All it takes to refute the IPCC and NAS assessments is credible evidence. Refuting IPCC and NAS proves to be a very difficult thing to do, however, because the assessments seek to incorporate all the credible evidence to begin with and to identify the limits to existing knowledge as well.

    Of course, new research often arises that relates to some part of the entire body of knowledge assessed by IPCC. When there are new and controversial findings, disagreements can occur within the scientific community (generally these play out in journals and at meetings). Sometimes more research is needed before we find out how things will resolve. This is how science moves forward.

    Attempts to stifle dissenting voices would be difficult and unwise if those who dissent have compelling evidence behind them. Scientists recognize the truth of Einstein’s quote: it is the evidence that wins out. So charges that scientists are ignoring evidence don’t make much sense. Any scientist who refuses to accept evidence that proves they are wrong will quickly look like a fool. Particularly since their colleagues will still have every reason to recognize the value of the new contribution.

    There is a critical distinction, however, between scientific debates and public debates. In public debates “evidence” that has been appropriately accounted for or debunked within the scientific community has a way of being widely repeated and spun in ways that are not scientifically defensible. This can be effective in public debates even when having no impact on scientific debates. Because of this, I’d be wary of public forums (op-eds, books, tv news, blogs, etc.) when they make arguments that supposedly refute reports from the IPCC or the National Academy of Sciences. -phiggins]

  2. tom s Says:

    Very eloquent Jim.

  3. tom s Says:

    Not to mention the meddling going on with the meteorlogical station data. The manipulation of temperature series’, some good but much bad. The non-archiving and unavailability of station data. Grid selection practices and statistical manipulation. The UHI problem which in my opinion (20 year operational meteorologist) is significantly undervalued. The fact that we use station data as a metric for a global mean temperature when in fact it is nothing but a statistically manipulated station data set.

    Politics has long ago taken the place of science in climate debate and it is only getting worse. Thank goodness there are some reputable “skeptics” of the alarmists views and much of the claims being made in the name of science out there. Steve McIntyre and Ross Mckintrick basically debunked the ‘Hockey Stick’ on their own and today it is not even referenced in the IPCC 4th assessment because of the NAS report on it’s ‘problems’. Yet in the main stream media and through the likes of Al Gore etc…the scientifically inept general public is beginning to buy into the predictions of doom and the politicians have stepped in to save the day (to garner votes from a scientifically ignorant public).

  4. Dr. Sanford Aranoff Says:

    Our government, together with the other major nations of the world, is actively working to reduce the increasing levels of carbon dioxide in the atmosphere. This flurry of intense activity is based upon the unproven Greenhouse Theory. According to this theory, increasing carbon dioxide and other greenhouse gases such as methane will cause the earth’s climate to dramatically heat up, with consequent serious loss of life and property. Discussions on this topic are shrill, full of emotional urgency. We are shouting that we must save the planet!

    [Response: You seem to conflate three issues here. The first is the natural greenhouse effect, about which there is no scientific disagreement. Without the greenhouse gases the surface of the earth would be too cold for life as we know it (you can read about this and other factors that affect the earth’s climate starting on page 96 in Chapter 1 of the WGI contribution to the IPCC’s FAR. The second issue is impact humans have had on the climate system. Scientists have established with 90-95% certainty that most of the warming observed over the last half century is due to human emissions of greenhouse gases (for more on this see the section starting on page 58 of the WGI Technical Summary). The third issue is what we do about human caused climate change. That is a question about policy, politics, values, and beliefs. As with most important and contentious policy debate, some shout and are more “shrill” as you say, while others remain calm and seek to work toward solutions. I see the full range of approaches from people with a wide range of opinions about policy options for addressing climate change. ClimatePolicy hopes to promote a more fully informed debate. -phiggins]

    If we were truly concerned about human life on earth, we would spend much more money doing research on Near Earth Objects, which can collide with the earth and damage us like a nuclear bomb. We have detected only about 10% of NEO’s. Once a dangerous NEO is detected, the solution is to send up a large rocket, which would nudge, by gravitational attraction, the orbit of the NEO away from us. We ignore this true dangerous issue at our peril. A NEO killed the dinosaurs. It is wrong to focus so much attention on the wrong problem.

    [Response:Risk can be thought of as the produce of the likelihood that an event will occur and the consequences if it does (as Mike Mastrandrea discussed here). For climate change, potentially serious consequences appear close at hand (that is to say occurring now and within decades). A collision between the earth and another object (a topic outside both my area of expertise and this websites focus) would seem to have at least potentially catastrophic consequences but is also an extremely low probability event. Keep in mind that the event that wiped out the dinosaurs occurred about 65 million years ago. That said, it makes sense to me to pay some attention to the possibility. It makes no sense to me, however, to ignore other serious problems that society faces, such as human caused climate change. -phiggins]

    The truth about carbon dioxide in the atmosphere, as we know from studies from the past centuries and millennia, is that when the earth heats up, the carbon dioxide levels in the atmosphere increase, several centuries later. The factual evidence is that climate warming CAUSES increasing carbon dioxide. Increasing carbon dioxide does not cause warming!

    [Response:You confuse responses and feedbacks here. You are correct that atmospheric carbon dioxide concentrations increased in response to warming (and decreased in response to cooling). However, those changing carbon dioxide concentrations also added to the warming (or cooling). Here’s the short explanation: warming out of glacial conditions was initiated by changes in the earth’s orbit. These orbital changes acted to reduce snow and ice cover, which increased the amount of solar radiation absorbed by the surface. That causes warming. That warming also causes an increase in carbon dioxide concentrations and that lead to more warming (which leads to more melting of snow and ice and higher greenhouse gas concentrations until the feedback loop fully runs its course). The opposite happens at the onset of ice-ages. To explain the temperature changes between ice ages and interglacial periods (the warm periods) takes three things: 1) changes in the earth’s orbit, 2) changes in snow and ice cover, and 3) changes in greenhouse gas concentrations. We can’t explain the temperatures without all three.

    For more from IPCC WGI on this see Sections 6.4.1 & 6.4.1.2 (orbital changes are also discussed specifically in box 6.1 of the chapter).

    This seems a good time to remind, however, that that this website is not the place for discussions about the details of climate science. We take the IPCC WGI assessment as the starting point for climate science and focus on climate policy. If you’re looking for scientific information then this IPCC WG I web page is the place to go. If you’re looking for debate about climate science, then I’d recommend realclimate. -phiggins]

    The actual cause of warming is the reduction of clouds that reflect sunlight. Cosmic rays that transverse the universe hit atoms in the atmosphere, ionizing them, and causing them to act like seed for cloud formation. The sun emits a stream of charged particles, called the solar wind. This stream is an electrical current and creates a magnetic field, which deflects the cosmic ray charged particles. The solar wind increases and decreases over a period of about 15 centuries. When the wind is high, as it is now, most cosmic rays are deflected, and there are not too many clouds. When the wind is low, cosmic rays get through, clouds are formed. It gets dark, dreary, and cold. We puny humans cannot do anything about the sun. It is going to get very cold and very warm every 15 centuries, and we have to adapt in order to survive.

    [Response:You’re taking a few leaps of faith here. Cosmic rays don’t correspond to cloud cover over the last decade and the evidence is ambiguous over the last fifty years. There’s also uncertainty about physical mechanisms that would link cosmic ray fluxes and cloud cover. Though a bit technical, you can read about all of this in section 2.7.1.3 of WGI’s report (especially the first full paragraph on page 193). Realclimate also has numerous posts on the topic like this one.

    In contrast, there is strong evidence for a connection between human emission of greenhouse gases and recent changes in climate. For comparison, IPCC classifies the evidence of the effect of greenhouse gases on climate as strong (the highest rating) and the role of cosmic radiation on climate as having insufficient evidence (IPCC’s the lowest designation). You can see this in Table 2.11 on page 201.

    What this all means is that you’re taking a bet with very long odds. That bet depends on 1) rejecting a great deal of scientific evidence supporting the role human greenhouse gas emissions have on climate and 2) believing that cosmic radiation is driving recent climate changes despite a lack of strong scientific evidence to support that (i.e., based on faith). To me, that implies a lack of scientific skepticism, which is one of the key components of scientific understanding. -phiggins]

    Now that the earth is warming up, we need to invest in electric power plants to supply our air conditioning needs. We need to invest in power in Africa and South America, so that they can have electric power, and not chop down trees for fuel that pollutes. Any money spent on Kyoto nonsense is wasted money.

    Please, dear reader, think for yourself, and not just believe what you are told. We now have access to the Internet, which can give us answers. The Greenhouse Theory is false as there is no evidence from historical records to justify the conclusions. For example, in 1940 there was a climate cooling which lasted decades, in spite of the huge increase of carbon dioxide. Look in history, and we can see major events correlated with the solar cycle. For example, the collapse of the Roman Empire was around the time of climate cooling due to the decrease of the solar wind. I have read scientific papers that claim to support the Greenhouse Theory. Sorry, but I do not agree with their conclusions, as they ignore historical evidence.

    Yes, we must reduce carbon dioxide and other atmospheric pollutants, in order to improve our health and quality of life. However, let us not say that we must reduce carbon dioxide or else the earth will get too hot!

    Al Gore made a passionate appeal for carbon dioxide reduction. He based this on the fact that our climate is warming. No one disagrees with this fact. The argument is the reason for the warming. No, Mr. Gore, it is not man-made activities. No, Mr. Gore, there is nothing human beings can do to change this. Accept reality and adapt. Build more power plants, including nuclear plants. Do research how we can safely build nuclear breeder reactors and fusion power. Our focus must be on how we adapt, not how we can act like God and change the sun!

    There is a serious question why do so many scientists, politicians, and media people persist in pushing this Greenhouse Theory nonsense. We need to examine this question carefully. Our leaders are not honest. Many scientists are also dishonest. Too many of us are corrupt. We are all in great danger from this corruption. Do such people view man as inherently destructive, instead of viewing people as inherently moral, trying to do the best for themselves and others?

    Thank you very much.

    [Response: You start off lamenting that discussions about climate change are “shrill” but then end by calling climate scientists and the politicians who worry about the risks of climate change dishonest. That seems inconsistent to me. In any case, I’ll take the opportunity to remind everyone that we welcome a substantive discussion but not personal attacks. -phiggins]


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