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Bending low with Bated breath

Filed under: — gavin @ 22 December 2018

“Shall I bend low and in a bondman’s key,
With bated breath and whisp’ring humbleness…?”

Shylock (Merchant of Venice, Act 1, Scene 3)

As dark nights draw in, the venerable contrarians at the GWPF are still up late commissioning silly pseudo-rebuttals to mainstream science. The latest, [but see update below] which no-one was awaiting with any kind of breath, is by Dr. Ray Bates (rtd.) which purports to be a take-down of the recent #SR15 report. As Peter Thorne (an IPCC author) correctly noted, this report is a “cut-and-paste of long-debunked arguments”. I’ve grown a little weary of diving down to rebut every repetitive piece of nonsense, but this one has a few funny aspects that make it worthwhile to do so.

When they go low, we go “sigh…”.

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Resplandy et al. correction and response

Filed under: — group @ 14 November 2018

Guest commentary from Ralph Keeling (UCSD)

I, with the other co-authors of Resplandy et al (2018), want to address two problems that came to our attention since publication of our paper in Nature last week. These problems do not invalidate the methodology or the new insights into ocean biogeochemistry on which it is based, but they do influence the mean rate of warming we infer, and more importantly, the uncertainties of that calculation.

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References

  1. L. Resplandy, R.F. Keeling, Y. Eddebbar, M.K. Brooks, R. Wang, L. Bopp, M.C. Long, J.P. Dunne, W. Koeve, and A. Oschlies, "Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition", Nature, vol. 563, pp. 105-108, 2018. http://dx.doi.org/10.1038/s41586-018-0651-8

Cracking the Climate Change Case

I have an op-ed in the New York Times this week:

How Scientists Cracked the Climate Change Case
The biggest crime scene on the planet is the planet. We know the earth is warming, but who or what is causing it?
Emilia Miękisz

Many of you will recognise the metaphor from previous Realclimate pieces (this is earliest one I think, from 2007), and indeed, the working title was “CSI: Planet Earth”. The process description and conclusions are drawn from multiple sources on the attribution of recent climate trends (here, here etc.), as well the data visualization for surface temperature trends at Bloomberg News.

There have been many comments about this on Twitter – most appreciative, some expected, and a few interesting. The expected criticisms come from people who mostly appear not to have read the piece at all (“Climate has changed before!” – a claim that no-one disputes), and a lot of pointless counter-arguments by assertion. Of the more interesting comment threads, was one started by Ted Nordhaus who asked

My response is basically that it might be old hat for him (and maybe many readers here), but I am constantly surprised at the number of people – even those concerned about climate – who are unaware of how we do attribution and how solid the science behind the IPCC statements is. And judging by many of the comments, it certainly isn’t the case that these pieces are only read by the already convinced. But asking how many people are helped to be persuaded by articles like this is a valid question, and I don’t really know the answer. Anyone?

If you doubt that the AMOC has weakened, read this

A few weeks ago, we’ve argued in a paper in Nature that the Atlantic overturning circulation (sometimes popularly dubbed the Gulf Stream System) has weakened significantly since the late 19th Century, with most of the decline happening since the mid-20th Century. We have since received much praise for our study from colleagues around the world (thanks for that). But there were also some questions and criticisms in the media, so I’d like to present a forum here for discussing these questions and hope that others (particularly those with a different view) will weigh in in the comments section below. More »

Transparency in climate science

Good thing? Of course.*

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Nenana Ice Classic 2018

Filed under: — gavin @ 1 May 2018

Another year, another ice out date. As in previous years, here’s an update of the Nenana Ice Classic time series (raw date, and then with a small adjustment for the calendrical variations in ‘spring’). One time series doesn’t prove much, but this is of course part of a much larger archive of phenomenological climate-related data that I’ve talked about before.

This year the ice on the Tanana River went out on May 1st, oddly enough the same date as last year, after another very warm (but quite snowy) Alaskan winter.



My shadow bet on whether any climate contrarian site will mention this dataset remains in play (none have since 2013 which was an record late year). [Update: It was mentioned on WUWT!]

The Alsup Aftermath

The presentations from the Climate Science tutorial last month have all been posted (links below), and Myles Allen (the first presenter for the plaintiffs) gives his impression of the events.
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Stronger evidence for a weaker Atlantic overturning circulation

Filed under: — stefan @ 11 April 2018

Through two new studies in Nature, the weakening of the Gulf Stream System is back in the scientific headlines. But even before that, interesting new papers have been published – high time for an update on this topic.

Let’s start with tomorrow’s issue of Nature, which besides the two new studies (one of which I was involved in) also includes a News&Views commentary. Everything revolves around the question of whether the Gulf Stream System has already weakened. Climate models predict this will be one consequence of global warming – alongside other problems such as rising sea levels and increasing heat waves, droughts and extreme precipitation. But is such a slowdown already underway today? This question is easier asked than answered. The Atlantic Meridional Overturning Circulation (AMOC, also known as Gulf Stream System) is a huge, three-dimensional flow system throughout the Atlantic, which fluctuates on different time scales. It is therefore by no means enough to put a current meter in the water at one or two points. More »

Alsup asks for answers

Some of you might have read about the lawsuit by a number of municipalities (including San Francisco and Oakland) against the major oil companies for damages (related primarily to sea level rise) caused by anthropogenic climate change. The legal details on standing, jurisdiction, etc. are all very interesting (follow @ColumbiaClimate for those details), but somewhat uniquely, the judge (William Alsup) has asked for a tutorial on climate science (2 hours of evidence from the plaintiffs and the defendents). Furthermore, he has posted a list of eight questions that he’d like the teams to answer.

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More ice-out and skating day data sets

Filed under: — gavin @ 26 February 2018

The responses to the last post on the Rideau Canal Skateway season changes were interesting, and led to a few pointers to additional data sets that show similar trends and some rather odd counter-points from the usual suspects.
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