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Impression from the ICTPLast week, there was a CORDEX workshop on regional climate modelling at International Centre for Theoretical Physics (ICTP), near Trieste, Italy.

The CORDEX initiative, as the abbreviation ‘COordinated Regional climate Downscaling Experiment‘ suggests, tries to bring together the community of regional climate modellers. At least, this initiative has got a blessing from the World Climate Research Programme WCRP.

I think the most important take-home message from the workshop is that the stake holders and end users of climate information should not look at just one simulation from global climate models, or just one downscaling method. This is very much in agreement with the recommendations from the IPCC Good Practice Guidance Paper. The main reason for this is the degree of uncertainties involved in regional climate modelling, as discussed in a previous post.

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Friday round-up

Filed under: — group @ 25 March 2011

Last week, Nature published another strong statement addressing the political/economic attack on climate science in an editorial titled “Into Ignorance“. It specifically criticized the right wing element of the U.S. Congress that is attempting to initiate legislation that would strip the US EPA of its powers to regulate greenhouse gases as pollutants. In so doing, it cited as an example the charade of a hearing conducted recently, including the Republicans’ disrespectful and ignorant attitude toward the science and scientists. Among many low points, this may have reached its nadir when a House member from Nebraska asked, smirkingly and out of the blue, whether nitrogen should be banned–presumably to make the point that atmospheric gases are all either harmless or outright beneficial, and hence, should not be regulated. Aside from the obvious difference that humans are not altering the nitrogen concentration of the atmosphere, as they are with (several) greenhouse gases, such a question boggles the mind in terms of the mindset that must exist to ask it in a public congressional hearing in the first place. But rarely are the ignorant and ideological bashful about showing it, regardless of who might be listening. In fact an increasing number seem to take it as a badge of honor.

There have been even more strongly worded editorials in the scientific literature recently as well. Trevors and Saier (2011)*, in a journal with a strong tradition of stating exactly where it stands with respect to public policy decisions and their effect on the environment, pull no punches in a recent editorial, describing the numerous societal problems caused when those with the limited perspective and biases born of a narrow economic outlook on the world, get control. These include the losses of critical thinking skills, social/community ethics, and the subsequent wise decision making and planning skills that lead a society to long-term health and stability.

Meanwhile, scientific bodies charged with understanding how the world actually works–instead of how they would imagine and proclaim it to–continue to issue official statements endorsing the consensus view that humans are strongly warming the planet in recent decades, primarily by greenhouse gas emissions to the atmosphere. Three years ago, we wondered whether geologists in general have a different view on climate change to the climate research community. A recent statement from the U.K. Geological Society, however, suggests that our impressions perhaps were not well-founded.

Notwithstanding these choices of ignorance, many other organizations continue apace with many worthwhile and diverse goals of how to deal with the problem. Here are a few links that we have run across in the last week or two that may be of interest to those interested in sustainability and adaptation. Please note the imminent deadlines on some of these.

The Center for Sustainable Development’s online courses related to community-level adaptation to climate change:

The CDKN International Research Call on Climate Compatible Development:

The Climate Frontlines call for abstracts for a July conference in Mexico City on the theme “Indigenous Peoples, Marginalized Populations and Climate Change” [Apologies: the official deadline for abstracts has apparently passed; view this is a conference announcement]

George Mason University’s call for votes on the Climate Change Communicator of the Year

*Trevors, J.T & Saier Jr., M.H. 2011. A vaccine against ignorance? Water, Air and Soil Pollution, DOI 10.1007/s11270-011-0773-1.

Blogging climate scientists

Filed under: — group @ 14 March 2011

The newest arrival in the climate science blogosphere is Isaac Held. This is notable in a number of respects. First, Isaac is a top-tier climate scientist who is hugely respected in the community. For him to decide that it is worth his time to blog on the science should be an important signal for other scientists. Secondly, Isaac is a federal NOAA employee at GFDL in Princeton, and the blog is on the official GFDL website.

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Under and over the ice

Filed under: — gavin @ 10 March 2011

I really like the fact that there is still so much to discover about important parts of the climate system. The Bell et al paper in Science Express this week (final version in Science) reporting on the surprising results from airborne ground-penetrating radar studies of the Antarctic Ice Sheet is a great example. The ice sheets themselves are the biggest challenge for climate modelling since we don’t have direct evidence of the many of the key processes that occur at the ice sheet base (for obvious reasons), nor even of what the topography or conditions are at the base itself. And of course, the future fate of the ice sheets and how they will dynamically respond to climate warming is hugely important for projections of sea level rise and polar hydrology. The fact that ice sheets will respond to warming is not in doubt (note the 4-6 m sea level rise during the last interglacial), but the speed at which that might happen is highly uncertain, though the other story this week shows it is ongoing.

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Wahl-to-Wahl coverage

Filed under: — gavin @ 9 March 2011

Eugene Wahl asked us to post a statement related to some incorrect claims circulating in the blogosphere:

The Daily Caller blog yesterday contained an inaccurate story regarding a correspondence that was part of the emails hacked from East Anglia University Climate Research Unit (CRU) in November 2009.

For the record, while I received the email from CRU as forwarded by Dr. Mann, the forwarded message came without any additional comment from Dr. Mann; there was no request from him to delete emails. At the time of the email in May 2008, I was employed by Alfred University, New York. I became a NOAA employee in August 2008.

The emails I deleted while a university employee are the correspondence I had with Dr. Briffa of CRU regarding the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, all of which have been in the public domain since the CRU hack in November 2009. This correspondence has been extensively examined and no misconduct found. As a NOAA employee, I follow agency record retention policies and associated guidance from information technology staff.

Dr. Eugene R. Wahl

March 9, 2011

Further questions can be addressed to Katy.G.Human -at- noaa.gov

Our comments

These claims are simply the latest attempt to try and manufacture scandals and smear scientists, particularly Mike Mann, based on the UEA emails. The story appears likely to have come from Senator Inhofe’s office who presumably had access to the transcripts taken by the NOAA Office of the Inspector General (whose investigation found no evidence of any wrongdoing by NOAA employees). The story was planted with Steve McIntyre, Anthony Watts, and Chris Horner, and then linked to by Inhofe’s office to provide a little plausible denialability – a rather blatant media spin operation.

But the facts of the case do not support the narrative they are pushing at all. While Jones’ original email was certainly ill-advised (as we stated immediately it came to light in Nov. 2009). Eugene Wahl was not subject to FOIA at the time (since he was not a federal employee) and was not subject to UK FOI anyway since he was working for a US-based university. Nor was he aware of any ongoing FOI actions in any case. In the original emails released, Mann stated that he would notify Wahl of Jones’ email, and his only involvement was to forward the Jones email to Wahl which Wahl’s account confirms.

So what is the actual issue at the heart of this? A single line in the IPCC AR4 report (p466) which correctly stated that “Wahl and Ammann (2006) also show that the impact [of the McIntyre and McKitirck critique] on the amplitude of the final reconstruction [by MBH98] was small (~0.05C)”. This was (and remains) true. During the drafting Keith Briffa corresponded with Eugene Wahl and others to ensure that the final text was accurate (which it was). Claims from McIntyre that this was not allowed under IPCC rules are just bogus – IPCC authors can consult with anyone they like at any time. However, this single line, whose inclusion made no effective difference to the IPCC presentation, nonetheless has driven continuing harassment of everyone involved for no good purpose whatsoever. Wahl and Ammann did show that MM05 made no substantial difference to the MBH reconstruction, whether it got said in the IPCC report or not.

That this inconvenient fact has driven hundreds of blog posts, dozens of fevered accusations, a basket load of FOI requests, and stoked multiple fires of manufactured outrage is far more a testimony to personal obsession, rather than to its intrinsic importance. The science of paleo-reconstructions has moved well beyond this issue, as has the interest of the general public in such minutiae. We can however expect the usual suspects to continue banging this drum, long after everyone else has gone home.

Live-blogging the climate science hearings

Filed under: — gavin @ 7 March 2011

I will be live-blogging the House Energy and Commerce committee hearings on climate science with Eli Kintisch. The details are available here, and there should be a live feed from the committee website from 10am.

Eli and I did this last year for the last Democrat-run hearings, and it went quite well – a little like a play-by-play from Eli and some background analysis/cites from me. People can ask questions and comment in real time and depending on how busy it gets, they might get a response.

As usual, this hearing will likely be long on political grandstanding and short on informed discussion, but there might be some gems. Of the witnesses, John Christy and Roger Pielke Sr. are the main witnesses for the majority side, while Richard Somerville, Francis Zwiers and Chris Field are the Dem invitees. There is newcomer to the roster (at least to me), in Knute Nadelhoffer, who presumably will discuss climate change impacts on biological systems (but I don’t really know). There is one out-of-left-field witness, Donald Roberts, who is a serially wrong DDT advocate who is probably there in order to dismiss environmental regulation in general, following the well-worn strategy described in Oreskes and Conway’s “Merchants of Doubt” (Chapter 7 on the revisionist attacks on Rachel Carson) (NB. DDT-related arguments are off topic for this blog, but for background of the specifics of the DDT ‘meme’ see this summary, and interested commenters are encouraged to go to Deltoid).

Anyway, for those who are aficionados of science as contact sport (TM, Steve Schneider), it might be fun.

Update: This was also live-blogged at ClimateCentral and twittered by UCS.

What we do not know in terms of adaptation

Filed under: — rasmus @ 7 March 2011

A recent paper by Oreskes et al. in the journal Philosophy of Science asserts that “there is a gap between the scale on which models produce consistent information and the scale on which humans act”. While the large scales, such as the global mean, provide the best indicators of the state of earth’s climate, it is on the local scales we feel a climate change, such as floods and extreme weather events. Extreme rainfall is usually local. So how is it possible then, as two new papers in Nature by Min et al. and Pall et al. (discussed here) have done, to attribute extreme precipitation and extreme UK floods to climate change?

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Glory (not to) be

Filed under: — gavin @ 4 March 2011

This morning one of the most important (and most delayed) satellite launches in ages took place. The mission was to launch the Glory satellite into a polar orbit, where three key instruments would have been looking at solar irradiance, aerosols and clouds. Unfortunately, one of the stages failed to separate and the satellite did not make orbit.

The irradiance measurements were to be an important continuation of the SORCE mission results, and are needed to stably continue the Total Solar Irradiance (TSI) timeseries. However the big new measurements were those associated with the Aerosol Polarimeter Sensor (APS). A similar instrument has flown in space twice before (the French-developed POLDER instrument), but unfortunately only for short periods. Its uniqueness lies in its ability to detect aerosols over bright surfaces (like land), and more importantly, to distinguish what kind of aerosols it is seeing. (Update: There is a third POLDER instrument, PARASOL, that is currently in orbit, see comments).

It may seem surprising, but despite many different attempts, almost all remote sensing of aerosols from space is only capable of detecting the total optical depth of all aerosols. MISR can provide some discrimination in special cases (picking out dust via a retrieval of non-spherical particles, or using the single scattering albedo to distinguish black carbon), but overall the estimates mix up sulphates, dust, black carbon, sea salt, nitrates and secondary organics. These originate from different processes, have different properties and different impacts on both radiation and clouds. Sea salt comes from sea spray over the oceans, dust from dry desert areas, black carbon from burning of forests and fossil fuels, sulphates derive from ocean plankton and burning coal, nitrates derive from fertiliser use, car exhausts and lightning, and secondary organics come from the stew of volatile organic compounds from industrial and natural sources alike. There are also pollen, and fat particles from outdoor cooking etc.

Because we can’t easily distinguish what’s what from space, we don’t have good global coverage of exactly how much of the aerosol is anthropogenic, and how much is natural. That uncertainty is a big player in the overall uncertainty in the human caused aerosol radiative forcing. Similarly, we have not been able to tell how much of the aerosol is capable of interacting with liquid or ice clouds (which depends on the different aerosols’ affinity for water), and that impacts our assessment of the aerosol indirect effect. These uncertainties are reflected in the model simulations of aerosol concentrations which all show similar total amounts, but have very different partitions among the different types.

The APS technology is a big step forward on these issues. It turns out that while the reflected SW from many different aerosols is similar, the polarisation of that reflected light depends quite strongly on what kind of aerosol it is. This varies depending on the angle at which the light is shining, So by scanning through the angles and measuring the polarisation, we can get a better constraint on the distribution of key aerosols. Scientists have already been working with aircraft mounted versions of the instrument, and this will continue.

The story of how this launch actually happened is very long and twisted, and needless to say, has taken far longer than anyone envisaged at the start (over a decade ago). With the failure to make orbit this morning, the wait will unfortunately go on.

This is of course a huge setback for the mission team (many of whom I know), and I can only imagine how frustrating this must be. The loss of OCO two years ago was due to a similar problem, though 3 launches since then have been successful (and the same system is being replicated as OCO-2). With the postponement of CLARREO in the proposed 2012 budget, there is a huge hole building in the US contribution to Earth and Sun observing systems.

Working from space is hard, expensive and risky. We cannot take it for granted, and yet we need that information more than ever.

Requiem for the Younger Dryas impact hypothesis?

Filed under: — gavin @ 1 March 2011

This is the strong conclusion of a new paper in the Earth Science Reviews by Pinter et al (via Scribd). From their abstract:

The Younger Dryas (YD) impact hypothesis is a recent theory that suggests that a cometary or meteoritic body or bodies hit and/or exploded over North America 12,900 years ago, causing the YD climate episode, extinction of Pleistocene megafauna, demise of the Clovis archaeological culture, and a range of other effects.

The physical evidence interpreted as signatures of an impact event can be separated into two groups. The first group consists of evidence that has been largely rejected by the scientific community and is no longer in widespread discussion…. The second group consists of evidence that has been active in recent research and discussions:…. Over time, however, these signatures have also seen contrary evidence rather than support.

In summary, none of the original YD impact signatures have been subsequently corroborated by independent tests. Of the 12 original lines of evidence, seven have so far proven to be non-reproducible. The remaining signatures instead seem to represent either (1) non-catastrophic mechanisms, and/or (2) terrestrial rather than extraterrestrial or impact-related sources.

The YD impact hypothesis made a big splash at AGU in 2007, and we’ve written about it a few times since. Our assessment was (in 2007), that this would need a lot of confirmatory evidence to get accepted, and even if it was, it did not provide much explanation for other, very similar, abrupt changes in the record. In 2009, we were still skeptical and noted that “the level of proof required for this extraordinary idea will need to be extraordinarily strong”. Unfortunately, as this paper makes clear, neither a lot of confirmatory evidence nor extraordinarily strong proofs have been forthcoming.

This paper is unlikely to the very last word on the subject, but it is likely to be the last time the mainstream paleo-climatologists are going to pay this much heed unless some really big new piece of evidence comes to light.

However, while the specifics of this particular hypothesis and its refutation are interesting in many ways…

The YD impact hypothesis provides a cautionary tale for researchers, the scientific community, the press, and the broader public.

Let’s be specific…
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Unforced variations: Mar 2011

Filed under: — group @ 1 March 2011

This month’s open thread for climate science discussions.