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- Why don’t op-eds get fact checked?November 30
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Debra Saunders is a conservative columnist for the San Francisco Chronicle who has a history of writing misleading contrarian pieces on climate change. She contacted NASA Public Affairs recently for a comment on the initial glitch on the October GHCN numbers (see this earlier post for discussions of that). They forwarded the query to me and since her questions were straightforward, I answered them as best I could. Indeed in her subsequent column, she quotes me accurately and in context. However, the rest of her column shows none of the same appreciation for basic journalistic standards.
She starts by asking why newspapers are no longer trusted - a good question, and one that may indeed be answerable. However the column quickly goes off the rails. First off, her headline "When the warmest year in history isn't" doesn't appear to be related to any actual content. Possibly it refers to the 1934/1998 hoohah from last year (again see
- Not the IPCC (“NIPCC”) ReportNovember 28
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Michael Mann and Gavin Schmidt
Much in the spirit of the Fraser Institute's damp squib we reported on last year, S. Fred Singer and his merry band of contrarian luminaries (financed by the notorious "Heartland Institute" we've commented on previously) served up a similarly dishonest 'assessment' of the science of climate change earlier this year in the form of what they call the "NIPCC" report (the "N" presumably standing for 'not the' or 'nonsense'). This seems to be making the rounds again as Singer and Heartland are gearing up for a reprise of last year's critically…er…appraised "Conference on Climate Change" this March. Recently some have asked us for our opinion of the report and so we've decided we ought to finally go ahead and opine. Here goes.
The fact that the very title of the report summary ("Nature, Not Human Activity, Rules the Climate") itself poses–at best–a false dichotomy is not an auspicious s - Mind the Gap!November 18
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Confusion has continued regarding trends in global temperatures. The misconception 'the global warming has stopped' still lives on in some minds. We have already discussed why this argument is flawed. So why have we failed to convince
?The confused argument hinges on one data set - the HadCRUT 3V - which is only one of several estimates, and it is the global temperature record that exhibits the least change over the last decade. Other temperature analyses suggest greater change (warming). Thus, one could argue that the HadCRUT 3V represents the lower estimate, if a warming could be defined for such a short interval.
- Mountains and molehillsNovember 11
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As many people will have read there was a glitch in the surface temperature record reporting for October. For many Russian stations (and some others), September temperatures were apparently copied over into October, giving an erroneous positive anomaly. The error appears to have been made somewhere between the reporting by the National Weather Services and NOAA's collation of the GHCN database. GISS, which produces one of the more visible analyses of this raw data, processed the input data as normal and ended up with an October anomaly that was too high. That analysis has now been pulled (in under 24 hours) while they await a correction of input data from NOAA (Update: now (partially) completed).
There were 90 stations for which October numbers equalled September numbers in the corrupted GHCN file for 2008 (out of 908). This compares with an average of about 16 stations each year in the last decade (some earlier years have bigger counts, but none as big as this month, and are much less as a percentage of stations). These other cases seem to be mostly legitimate tropical stations where there isn't much of a seasonal cycle. That makes it a little tricky to automatically scan for this problem, but putting in a chec
- FAQ on climate modelsNovember 3
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We discuss climate models a lot, and from the comments here and in other forums it's clear that there remains a great deal of confusion about what climate models do and how their results should be interpreted. This post is designed to be a FAQ for climate model questions - of which a few are already given. If you have comments or other questions, ask them as concisely as possible in the comment section and if they are of enough interest, we'll add them to the post so that we can have a resource for future discussions. (We would ask that you please focus on real questions that have real answers and, as always, avoid rhetorical excesses).
Quick definitions:
- GCM - General Circulation Model (sometimes Global Climate Model) which includes the physics of the atmosphere and often the ocean, sea ice and land surface as well.
- Simulation - a single experiment with a GCM
- Initial Condition Ensemble - a set of simulations using a single GCM but with slight perturbations in the initial conditions. This is an attempt to average over chaotic behaviour in the weather.
- Multi-model Ensemble - a set of simulations from multiple models. Surprisingly, an average over these simulations gives a better match to climatological observations than any single model.
- Model weather - the path that any individual simulation will take has very different individual storms and wave patterns than any other simulation. The model weat