The Dutch view on the future of the IPCC – what it does and what it does not say

July 15, 2013 by

Guest post by Hans Custers. Dutch version is here.

The IPCC invited the governments of all participating countries to give their view on the future of the climate panel. The IPCC is a complex organization, dealing with a very complex subject, so perfection will be impossible to achieve. Or, from an optimistic point of view: there’s always room for improvement. And of course, a transparent process of self-reflection is a very good start for improvements. But well, this is the IPCC, so there is a catch. Whatever happens in this process, it will be spun by the anti IPCC and anti climate science campaign as ‘evidence’ for their claims. Every bit of criticism on the IPCC’s procedures and methods will be spun as substantial criticism on the scientific content of the assessment reports. And if governments would be reluctant to criticize, because they know it will be taken out of context, it would be seen as ‘evidence’ for the huge climate conspiracy.

The Netherlands has finished their submission and it was published (pdf) on KNMI’s website early last month. In my opinion they did what they should have done: they presented a straightforward view, not worrying about the inevitable spin by the skeptic campaign. And, oh yeah, inevitable it was. The next quote appeared in internet discussions again and again, after skeptics found the submission:

The IPCC needs to adjust its principles. We believe that limiting the scope of the IPCC to human-induced climate change is undesirable, especially because natural climate change is a crucial part of the total understanding of the climate system, including human-induced climate change. The Netherlands is also of the opinion that the word ‘comprehensive’ may have to be deleted, because producing comprehensive assessments becomes virtually impossible with the ever expanding body of knowledge and IPCC may be more relevant by producing more special reports on topics that are new and controversial.

Skeptics don’t seem to understand, or don’t want to understand, that this is about the IPCC organization only, and not about the content of assessment reports, or even climate science in general. They suggest the Dutch government thinks that natural influences and controversial topics may have been underestimated in previous assessments. There are some things they overlook.

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EGU General Assembly: The Arctic, Models, and Data

June 7, 2013 by

Guest post by Heleen van Soest

In April, the annual European Geosciences Union conference was held in Vienna, Austria. Heleen van Soest, MSc student Climate Studies at Wageningen University, attended the conference, and shares some thoughts and tweets (@Hel1vs).

The opening reception, April 7, reveals that geoscientists are fond of beer. I get to talk to some nice people and hand out my first business cards. Yay! I talk with Walter Schmidt,  President of the Division on Geosciences Instrumentation and Data Systems, about observations and data. Lesson learned: data are important, but never take them for granted. Especially from satellites: they basically measure counts and voltages. To interpret the numbers and get something useful, we already need models, i.e. algorithms. Usually, model skill is tested against data. Disagreement between them is often blamed on model errors, assumptions, etc. Keep in mind that data might be wrong, too. Fortunately, raw data is increasingly archived as such, together with the algorithms used to interpret them. In that way, data can still be used if the algorithms are updated. I dedicate my first #egu2013 tweet to this conversation and go home. I am happy to find a Va Piano (Italian restaurant) in ‘my’ street. Together with Sherlock Holmes (the book, that is), I eat my pasta.

Tweet At #egu2013 opening reception, interesting conversation about models and data: “important, but never take them for granted” (Walter Schmidt)

Monday, 8 April

Permafrost day. An important issue, as permafrost contains about half of the world’s soil carbon. If permafrost thaws, the organic carbon becomes available for microbes to degrade. Greenhouse gas (methane) emissions are a result, further increasing temperatures. This positive feedback is sometimes compared to a time bomb. Modelling studies of permafrost do show it will degrade under further warming. For example, Greenland permafrost south of 76°N will disintegrate this century. However, see RealClimate before you start to worry that this bomb is about to explode.

But today is not only permafrost; I’ve also got something on ice observations.

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Consensus: Behind the numbers

May 17, 2013 by

The much reported paper by John Cook et al finds a very strong consensus about human caused climate change in the scientific literature: Of those abstracts expressing a position on the cause of global warming, 97% (implicitly or explicitly) endorsed human causation of this warming.

Over at Lucia’s, Brandon Shollenberger  found a way to search the results of 12,280 out of 12,465 papers. Based on this search method and the SkS paper rating guidelines, Marcel Crok reports the following breakdown of results:

Category 1 (explicit endorsement with quantification): 65
Category 2 (Explicit Endorsement without quantification): 934
Category 3 (Implicit Endorsement): 2933
Category 4 (Neutral): 7930 [the reported number]
Category 5 (Implicit Rejection): 53
Category 6 (Explicit Rejection without quantification): 15
Category 7 (Explicit Rejection with quantification): 10

The 97% is arrived at by adding up categories 1 to 3 and taking that as a percentage of all categories except 4. This percentage is actually 98% using the numbers above, but these are obtained via a shortcut.

Of course, various other fractions could be calculated from this list, each with a slightly different meaning.  E.g. of those abstracts making a statement about the quantitative contribution of human activity to the warming, 87% (65/75) endorsed dominant human causation. And of those abstracts expressing an explicit position on the cause of global warming, 97.6% (999/1024) endorsed human causation.

Any way you slice it, a strong consensus it is.

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Long term persistence and internal climate variability

April 30, 2013 by

After a long hiatus, Climate Dialogue has just opened a second discussion. This time it’s about the presence of long term persistence in timeseries of global average temperature, and its implications (if any) for internal variability of the climate system and for trend significance. This discussion is strongly related to the question of whether global warming could just be a random walk, a question vigorously debated on this blog (incl my classic  april fool’s day post three years ago).

Invited expert participants in the discussion include Rasmus Benestad (of RealClimate fame), Demetris Koutsoyiannis and Armin Bunde. The introduction text here slightly differs from that posted on ClimateDialogue.org

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Documentairy “Thin Ice” now available on the web

April 22, 2013 by

The documentairy “Thin Ice“, with spectacular images and interviews with a few dozen of well-known and lesser well-known climate scientists, is available for viewing tonight on their website (which features lots of other interesting content btw). At the same time, various public screenings are being organized all over the world (unfortunately not in the Netherlands, mea culpa). The free viewing via their website is probably temporary, though I don’t know for how long (my guess is a few days). The premiere has of course been timed to coincide with Earth Day.

Melting of the Arctic sea ice

March 25, 2013 by

Guest post by Jos Hagelaars. Dutch version is here.

This was the title of a discussion that was held on the recently launched website ClimateDialogue regarding the possible causes of the decline in Arctic sea ice over the past decades. Three experts participated in this discussion: Walt Meier, Research Scientist at the NSIDC, Judith Curry, professor at Georgia Institute of Technology and Ron Lindsay, Senior Principal Physicist at the Polar Science Center of the University of Washington.

In this blog post I will start off with a description of the observations of the Arctic region, followed by a short overview of the potential causes of the decline in Arctic sea ice, incorporating the views of the three experts as they were expressed on ClimateDialogue. The final parts concern the uniqueness of this decline in a historical perspective and the possibility of having an ice-free Arctic in the summer in the not too distant future.

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Observations of the Arctic region since 1979

Since 1979 the Arctic region has been extensively monitored by satellites. They detect e.g. the ice surface area, the extent of the area covered with ice and also the total amount or volume of ice. The results of these observations are startling. For example, sea ice area and the amount of perennial (multi-year) ice has decreased dramatically over the past 3 decades, as is visualized by the images in figure 1 and 2, generated by NASA (see here and here).

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The two epochs of Marcott

March 19, 2013 by

Guest post by Jos Hagelaars. Dutch version is here.

The big picture (or as some call it: the Wheelchair): Global average temperature since the last ice age (20,000 BC) up to the not-too distant future (2100) under a middle-of-the-road emission scenario.

Shakun_Marcott_HadCRUT4_A1B_Eng

Figure 1: The temperature reconstruction of Shakun et al (green – shifted manually by 0.25 degrees), of Marcott et al (blue), combined with the instrumental period data from HadCRUT4 (red) and the model average of IPCC projections for the A1B scenario up to 2100 (orange).

Earlier this month an article was published in Science about a temperature reconstruction regarding the past 11,000 years. The lead author is Shaun Marcott from Oregon State University and the second author Jeremy Shakun, who may be familiar from the interesting study that was published last year on the relationship between CO2 and temperature during the last deglaciation. The temperature reconstruction of Marcott is the first one that covers the entire period of the Holocene. Naturally this reconstruction is not  perfect, and some details will probably change in the future. A normal part of the scientific process.

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Response to John Christy’s blog post regarding ‘Klotzbach Revisited’

March 5, 2013 by

Guest blog by Jos Hagelaars

Dr. John Christy wrote an extensive blog post as a response to my Dutch ‘Klotzbach Revisited’ post (English version here), it is published on “Staat van het Klimaat” and WUWT. I would like to thank Dr. Christy for his interest in my writings.

I have some remarks regarding Dr. Christy’s post, which are addressed in this ‘response-post’ and are built upon some quotes taken from Dr. Christy’s response.
For reference, the original Klotzbach et al 2009 paper (K-2009 in the text) can be found here and the correction paper (K-2010) can be found here.

“Klotzbach et al.’s main point was that a direct comparison of the relationship of the magnitude of surface temperature trends vs. temperature trends of the troposphere revealed an inconsistency with model projections of the same quantities.”

This ‘main point’ is not present at all in the K-2009 paper, the only reference to real data coming from a climate model in the paper is the amplification factor, which was ‘sort of obtained’ by Ross McKitrick from the GISS-ER model. In the abstract a short conclusion is given: “These findings strongly suggest that there remain important inconsistencies between surface and satellite records.”. No word about models.

In my opinion the main point of K-2009 is the suggestion that the surface temperature record is biased. One third of the paper is made up by paragraph 2 with the title: “Recent Evidence of Biases in the Surface Temperature Record”. K-2009 explicitly state:
In our current paper, we consider the possible existence of a warm bias in the surface temperature trend analyses …

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Klotzbach Revisited

March 1, 2013 by

Guest blog by Jos Hagelaars. Dutch version here.

The average surface temperature of the earth, measured by ‘thermometers’, are released by a number of institutes, the most well-known of these datasets are GISTEMP, HadCRUT and NCDC. Since 1979 temperature data for the lower troposphere are released by the University of Alabama in Huntsville (UAH) and Remote Sensing Systems (RSS), which are measured by satellites.
The temperatures of these two methods of measurement show differences, for instance: the NCDC data indicate a trend over land of 0.27 °C/decade for the period 1979 up to and including 2012, while over the same period, the trend based upon the satellite data by UAH over land is significantly lower at 0.18 °C/decade. In contrast, the trends for global temperatures indicate much smaller differences, for NCDC and UAH these are respectively 0.15 °C/decade and 0.14 °C/decade for the same period.

Big deal? Almost everything related to climate is a ‘big deal’, so it is of no surprise that the same applies to these trend differences. In a warming world it is expected that the temperatures of the upper troposphere increase at a higher rate than at the surface, regardless of the cause of the warming. The satellite data (UAH and RSS) do not reflect this. Why is the upper troposphere expected to warm at a higher rate and what is the cause of these trend differences between the surface  and satellite temperatures?

The temperature gradient in the troposphere / the ‘lapse rate’

When you go up in the troposphere it gets colder. This is caused by the fact that rising air will cool down with increasing altitude due to a decrease in pressure with altitude, by means of so-called adiabatic processes. This temperature gradient is called the lapse rate, a concept one will frequently encounter in papers regarding the atmosphere in relation to climate. When the air is dry, this temperature drop is about 10 °C per km. When the air contains water vapor, this vapor will condense to water upon cooling as a result of the rising of the air, which releases heat of condensation. So in this way, heat is transported to higher altitudes and the temperature drop with height will decrease. For air saturated with water vapor, this vertical temperature drop is approximately 6 °C per km.

When the earth gets warmer, air can contain more water vapor. This also has an impact on the lapse rate, since more water vapor means more heat transfer to higher altitudes. This effect on the lapse rate is called the lapse rate feedback. More heat at higher altitudes implies that there will be more emission of infrared light, a negative feedback. This effect is particularly important in the tropics. At higher latitudes, the increase in temperature at the surface is dominant, therefore the change in the lapse rate will turn into a positive feedback. See figure 1 (adapted from the climate dynamics webpage of the University of Leuven).

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Launching ClimateDialogue.org

November 14, 2012 by

Guestpost by ClimateDialogue editors Rob van Dorland, Bart Strengers and Marcel Crok

ClimateDialogue.org
Exploring different views on climate change

Goal of ClimateDialogue.org
ClimateDialogue.org offers a platform for discussions between invited climate scientists on important climate topics that have been subject to scientific and public debate. The goal of the platform is to explore the full range of views currently held by scientists by inviting experts with different views on the topic of discussion. We encourage the invited scientists to formulate their own personal scientific views; they are not asked to act as representatives for any particular group in the climate debate.

Obviously, there are many excellent blogs that facilitate discussions between climate experts, but as the climate debate is highly polarized and politicized, blog discussions between experts with opposing views are rare.

Background
The discovery, early 2010, of a number of errors in the Fourth IPCC Assessment Report on climate impacts (Working Group II), led to a review of the processes and procedures of the IPCC by the InterAcademy Council (IAC). The IAC-report triggered a debate in the Dutch Parliament about the reliability of climate science in general. Based on the IAC-recommendation that ‘the full range of views’ should be covered in the IPCC-reports, Parliament asked the Dutch government ‘to also involve climate skeptics in future studies on climate change’.

In response, the Ministry of Infrastructure and the Environment announced a number of projects that are aimed to increase this involvement. Climate Dialogue is one of these projects.

Topics
We are starting Climate Dialogue with a discussion on the causes of the decline of the Arctic Sea Ice, and the question to what extent this decline can be explained by global warming. Also, the projected timing of the first year that the Arctic will be ice free will be discussed. With respect to the latter, in its Fourth Assessment Report in 2007, IPCC anticipated that (near) ice free conditions might occur by the end of this century. Since then, several studies have indicated this could be between 2030-2050, or even earlier.

We invited three experts to take part in the discussion: Judith Curry, chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology; Walt Meier, research scientist at the National Snow & Ice Data Center (NSIDC) in Boulder, Colorado; and Ron Lindsay, Senior Principal Physicist at the Polar Science Center of the University of Washington in Seattle.

Future topics that will be discussed  include: climate sensitivity, sea level rise, urban heat island-effects, the value of comprehensive climate models, ocean heat storage, and the warming trend over the past few decades.

Our format
Each discussion will be kicked off by a short introduction written by the editorial staff, followed by a guest blog by two or more invited scientists. The scientists will start the discussion by responding to each other’s arguments. It is not the goal of Climate Dialogue to reach a consensus, but to stimulate the discussion and to make clear what the discussants agree or disagree on and why.
To round off the discussion on a particular topic, the Climate Dialogue editor will write a summary, describing the areas of agreement and disagreement between the discussants. The participants will be asked to approve this final article, the discussion between the experts on that topic will then be closed and the editorial board will open a new discussion on a different topic.

The public (including other climate scientists) is also free to comment, but for practical reasons these comments will be shown separately.

The project organization consists of an editorial staff of three people and an advisory board of seven people, all of whom are based in the Netherlands. The editorial staff is concerned with the day-to-day operation of researching topics, finding participants for the discussion and moderating the discussions between the experts. The main task of the advisory board is to guard the neutrality of the platform and to advise the editorial staff about its activities

Editorial Staff
Project leader is Rob van Dorland of the Royal Netherlands Meteorological Institute (KNMI). Van Dorland is a senior scientist and climate advisor in the Climate Services section and is often operating at the interface between science and society.

The second member is Bart Strengers. He is a climate policy analyst and modeler in the IMAGE-project at the PBL Netherlands Environmental Assessment Agency (PBL) and has been involved in the discussion with climate skeptics for many years.

The third member is Marcel Crok, an investigative science writer, who published a critical book (in Dutch) about the climate debate.

Questions
We welcome comments on this blog and are happy to answer any questions regarding this project. You can send an email to info [at] climatedialogue [dot] org.

Postscript (Bart V):

(Disclaimer: I am involved in this initiative as a member of the advisory board)

I think ClimateDialogue is a unique project in both its organization (people with wildly different views are involved) and in its aim: Facilitating a public discussion between scientists with strongly differing opinions.

Discussion topics are chosen to be relevant and interesting to the general public as well as receiving scientific attention. Discussants are chosen to reflect different stances in the spectrum of scientific opinion, explicitly including ‘sceptical’ voices. Naturally, the ensuing discussion is not necessarily representative of the full spectrum of scientific discussion (painting it as such would likely lead to a ‘false balance’).

The idea is that the discussion can alleviate the polarization between ‘sceptics’ and ‘mainstreamers’ and provide some clarity in background of the (dis)agreements. Moreover, having scientists discuss their scientific disagreements in a public setting can go a long way to increase the public trust in science, which has suffered from the (imho incorrect) impression of being closed-minded. All in all, I think that ClimateDialogue provides a valuable service to both the public and the scientific debate. That doesn’t mean that it’s free of risks, but these are more in the framing and the perception than in the discussions itself. Naturally, the participation of good scientists is a necessary condition to make this experiment a success. Don’t hesitate to contact the editors (or me) if you fit the bill and are not afraid of a public debate!


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