Growing ice is evidence of warming

With Antarctic sea ice breaking extent records again this week, the green fraternity has been forced to go the full Monty on the PR front in an effort to negate the impact. In an article today, Grist reports that the ever-expanding sea ice is in fact bad news.

I kid you not.

For the third year in a row, the sea ice ringing Antarctica has set a new record. Its extent is the farthest now since observations began in the late ’70s, and scientists say the growth is largely the result of climate change.

Antarctic sea ice melts during the early part of the year but typically packs it back on by September. The ice broke last year’s record for extent on Monday, according to a report in New Scientist. It’s the latest evidence of a small but significant growth trend of about 1.5 percent per decade.

More sea ice is evidence of global warming. Less sea ice is global warming. 

The problem is, I think they probably actually believe what they are saying. Their mystification as to why other people might not be convinced is a wonder to behold.

Antarctic confusion

With the sea ice in Antarctica breaking extent records again this week, New Scientist seems to have taken it upon itself to engage in a bit of damage limitation on behalf of the global warming movement. Its article today declares that the growth in sea ice is in fact caused by global warming (who would have thought it?!). 

There doesn’t actually seem to be any research to back this up – there is no link to a new paper or anything like that. We just have a couple of talking heads with a rather impenetrable explanation of their case:

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The pause and its coming of age

There should be a big coming of age party for the pause in the next month or so. On one measure it's now 17 years, 11 months old, so depending what temperatures do in the near future the pause should be heading for the local boozer for its first pint.

In fact on other measures the pause is already well into adulthood, as Matt Ridley reports in the Wall Street Journal.

Well, the pause has now lasted for 16, 19 or 26 years—depending on whether you choose the surface temperature record or one of two satellite records of the lower atmosphere. That’s according to a new statistical calculation by Ross McKitrick, a professor of economics at the University of Guelph in Canada.

It has been roughly two decades since there was a trend in temperature significantly different from zero. The burst of warming that preceded the millennium lasted about 20 years and was preceded by 30 years of slight cooling after 1940.

This has taken me by surprise. I was among those who thought the pause was a blip. As a “lukewarmer,” I’ve long thought that man-made carbon-dioxide emissions will raise global temperatures, but that this effect will not be amplified much by feedbacks from extra water vapor and clouds, so the world will probably be only a bit more than one degree Celsius warmer in 2100 than today. By contrast, the assumption built into the average climate model is that water-vapor feedback will treble the effect of carbon dioxide.

But now I worry that I am exaggerating, rather than underplaying, the likely warming.

Arctic ice on the up

David Rose has an article in the Mail on Sunday about the rapid recovery in Arctic sea ice over the last couple of years.

The speech by former US Vice-President Al Gore was apocalyptic. ‘The North Polar ice cap is falling off a cliff,’ he said. ‘It could be completely gone in summer in as little as seven years. Seven years from now.’

Those comments came in 2007 as Mr Gore accepted the Nobel Peace Prize for his campaigning on climate change.

But seven years after his warning, The Mail on Sunday can reveal that, far from vanishing, the Arctic ice cap has expanded for the second year in succession – with a surge, depending on how you measure it, of between 43 and 63 per cent since 2012.

Hiding the pause

Corrine le Quere of UEA is another of the scientists who were asked to address the All-party Climate Change Group about AR5, her topic being what is the evidence for that man is causing climate change. Audio is here, her slides can be seen here, an example of which is shown below:

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More on GCMs and public policy

Richard Betts posted some further thoughts on GCMs and public policy in the previous post on this subject. Since the thread is now heading for 300 comments I thought I'd post his ideas up here and respond in turn.

Richard first set out his understanding of my position.

I'd initially thought that you were claiming that the very need for any kind of climate policy was based on GCMs. Clearly it isn't, for the reasons I stated, but it seems this isn't your point here anyway. You seem to be moving a step further and talking about the importance of GCMs to the details of climate policy (eg. a carbon tax). Here I do partially agree with you - GCMs do of course play a role in the details, as they help with understanding the climate system, but they are by no means the only source of information. Moreover, I don't think the examples you give would be substantially affected if we didn't have GCMs.

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Before the deluge

Last night climatologist Gareth Jones tweeted that there had been two dozen papers on the pause this year. In response, I wondered how many would have been published if David Whitehouse hadn't have written his groundbreaking report on the subject. This prompted Doug McNeall to comment "About two dozen", a sentiment that was endorsed by Gavin Schmidt.

It's always nice to be challenged, so I thought I'd look into this a bit. Take a look at Google Trends:

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Lewis on Chen and Tung

Nic Lewis emails:

I am sorry to see that Piers Forster has given what I consider to be an incorrect statement to the Guardian (p.19) regarding the new Chen & Tung Science paper about the Atlantic storing excess heat. He is quoted as saying: "Most importantly, this paper is another nail in the coffin of the idea that the hiatus is evidence that our projections of long-term climate change need revising down."

The paper very much supports the view of those scientists, including myself, who consider that natural variability in the ocean significantly affects surface warming trends on a multidecadal basis. It does not support the view that a reduction in the rate of increase in radiative forcing caused by aerosols, solar variations, reduction in stratospheric water vapour, etc. is the prime cause of the hiatus.

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It's the Atlantic wot dunnit

Updated on Aug 22, 2014 by Bishop Hill

Overnight the big climate news has been the new paper by Chen and Tung, which seeks to explain the pause in surface temperature rise, now nearly 18 years old on some measures. Judith Curry has excerpts here, while a layman's summary is available at the Economist.

The story goes that much of the missing heat is to be found in the Atlantic, with a slow-moving current speeding up in recent times so that heat is drawn down into the deep-ocean. The theory seems to be that this process runs over a 60-year cycle, for half the time with the depths warming and the surface cooling and half the time the other way round. Chen and Tung conclude that we are currently in a surface cooling phase, so the pause could last another ten years or more.

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Arctic life spiral

The decline of the Arctic sea ice is a perennial favourite among our millennarian friends, with "Death Spiral" being  favoured buzzwords used to keep the subject in the front of people's minds. Here's an example from shouty* (official) skeptic Phil Plait.

However, new light is thrown on the subject by a paper in Geophysical Research Letters (H/T Hockey Schtick) which finds strong covariability between sea ice levels and the Atlantic Multidecadal Oscillation. In other words a significant chunk of the variability seems to be entirely natural.

It's life, Jim, and just as we know it.

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*Is it just me, or is everyone involved in the Skeptics Society incapable of speaking without shouting?

Lean outdoes himself

Even by his own high standards, Geoffrey Lean's latest piece in the Telegraph, is quite extraordinarily daft, a silly piece, from a silly journalist, for the silly season.

Global warming, climate sceptics keep saying, has stopped for the last 16 years or so...The sceptics base their claim on just one measurement of warming, the temperature of air near the earth's surface , whose increase has indeed slowed down recently, though it has not stopped growing.

This is of course drivel. Sceptics do not base this claim on only one measurement. Satellite measurements of the troposphere show the pause just as the surface temperatures do. Global sea ice levels remain above their long-term average. And the pause is clearly visible in the current graph from GISSTEMP, the only record that has been alleged to still show a positive trend this century.

Lean then goes on to say that sea surface temperatures around the UK have gone up by, erm, 1.6% (although I'm not sure if he is working in Kelvin or Centigrade!) and goes on to say that this is affecting fish ranges:

Cod and haddock, for example, are now rarely found wild in British waters. They are being replaced by warmer water species like sea bass, hake, gurnard, red mullet and anchovies, while John Dory – once only found off Cornwall – has spread through the North Sea up to Scotland. Diets, however, have yet to change to match.

Do you think the cod and haddock thing might be something to do with overfishing? And what about the warm-water species thing? This paper shows a considerable John Dory catch off the Hebrides in the mid-1990s (see Fig 2). Red mullet are found halfway to Iceland. And while we are about it, it's also worth pointing out that top-of-the-ocean temperatures are another climate series that shows a pause, whether you find such records convincing or not.

And newspaper owners wonder why they are going out of business.

Climate's parliamentary cheerleaders

The House of Commons Energy and Climate Change Committee has released its report into the IPCC's Fifth Assessment Report. This is fascinating stuff, if only to see all the intellectual contortions that have been adopted by committee staffers in arriving at the required answer, namely that everything is hunky dory with climate science and the IPCC.

The press release is here and consists of standard parliamentary cheerleading of the kind that has "sod the constituents" written all over it (Tim Yeo is quoted extensively, so I guess that follows).

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Read all about it

There are a great collection of stories in the Mail on Sunday this morning, with a story and leader on the idiocy of smart meters and a story on Antarctic Sea ice from David Rose. The latter is accompanied by a comment piece by someone called "Andrew Mountford". I think they got it right in the print edition.

Where there is harmony, let us create discord

Updated on Jul 3, 2014 by Bishop Hill

My recent posts touching on statistical significance in the surface temperature records have prompted some interesting responses from upholders of the climate consensus, with the general theme being that Doug Keenan and I don't know what we are talking about.

This is odd, because as far as I can tell, everyone is in complete agreement.

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The debate at the FST

A report of the recent climate change discussion at the Foundation for Science and Technology has been published here. Audio of the main speakers is available from the FST's website.

Featuring Mark Walport, Jim Skea, Peter Lilley and David Davies, the subject was "What is the right level of response to anthropogenic induced climate change?". From the report of proceedings, little new ground was broken. I was, however, interested to learn from Walport that it is "clear" that climate change is happening and that its impacts are already evident, a position of delicious imprecision: I imagine we are supposed to infer that he means manmade climate change, but of course manmade climate change is not "clear". As I have mentioned previously, I have put it to Walport that we are unable to demonstrate a statistically significant change in surface temperatures because of the difficulty in defining a statistical model that would describe the normal behaviour of surface temperatures, a claim that seems to have the support of the Met Office. I don't know of any other metric in which a statistically significant change has been demonstrated. Walport did not dispute my position on surface temperatures but suggested that seeing many observational metrics moving together led to a conclusion that manmade global warming was upon us.

This may be the case, but I wonder if there is a robust statistical analysis of to support Walport's position. Perhaps a letter is in order.

(Please could we avoid comments that are simply venting about Walport - stick to the issues please.)