Precipitation and El Nino

Recently there has been a number of blog postings linking temperature and El Nino. Tamino (http://tamino.wordpress.com/2011/12/06/the-real-global-warming-signal/) based on a paper by Foster and Rahmstorf used the link to show that global warming had not levelled off. Meanwhile Frank Lansner at WUWT did a similar analysis to show that there had been a levelling off.

One thing which always surprises me is the importance given to temperature by comparison with that given to precipitation. This is very much the case with the previous IPCC report and I am posting it here in the hope that this will change. Within certain wide limits what matters to people is not temperature, and by inference evaporation, but the balance between evaporation and temperature.

The following graph shows a regression plot of precipitation and an El Nino index. The precipitation is based on the NCDC global precipitation anomaly with a 5-month centred moving average. The El Nino index is the NOAA's Oceanic El Nino Index (ONI).



This shows that global precipitation and El Nino are correlated.

The next plots shows the variation in precipiation and the ONI. The precipitation is as above and the ONI is inverted (i.e. the original value multipied by -1).



As can be the two are closely related in both magnitude and timing. The fact that the two are synchronous suggests that neither is forcing the other but that both are a result of a common factor.

In TAR4 very little information was given on the simulation of precipitation by climate models. One of the reasons might have been the fact that the models did not represent the sort of variations shown above.

This should be addressed in TAR5.

IPCC Technical Assessment Report 5 – Thesis 3

Thesis: The presentation of sea ice in TAR4 used only a sub-set of the data. It should use a wider range of data with reference both to data which were available at the time of TAR4, and data which have become available since.

The technical summary presents the following set of graphs:

 

The way the graphs are presented is reminiscent of graphs of return on investment of rivals presented by some of the less honest financial intermediaries.  Those for the Arctic are presented as anomalies with a scale set so that the full range fits in the rectangle and it seems as if ice extent has fallen close to zero. For the Antarctic, where the area of ice has been tending to increase, they have used the same scale which conveniently minimises the increasing tendency of Antarctic ice.

The following graph presents the same data, updated to May 2010, but as extent not anomalies.

This very clearly shows that on average there are similar areas of sea ice in the Arctic and Antarctic, that the variation is much larger in the Antarctic than the Arctic and the loss of sea ice in the Arctic is only partially balanced by the gain in the Antarctic.  A linear regression through the average values suggests that the Arctic has lost 50,000 km² per year whereas the Antarctic has gained 14,000 km2 per year. The average total area of sea ice 23.9 million km² so this loss represents a rate of 0.15% a year.

The Synthesis Report also mentions the break-up of the Larsen B ice shelf.  This was an area of ice partly floating and partly resting on land and joined to the main Antarctic ice shelf. It was located on the most northerly (i.e. warmest) point of the Antarctic. The area of the ice shelf was 3250 km² and its weight was 72 billion tons. The loss of the ice shelf has become iconic and it has been compared to the area of Rhode Island or to the trillions of 20 lb bags which could be filled (though not in the IPCC report).  In relation to the area of the Antarctic ice sheet it represents only 0.02% of the area or 0.003% of the volume.

We do recognise that the minimum area of sea ice is a useful metric. The albedo (reflectivity) of ice is high and that of sea water is low. In summer, when ice is at a minimum and sunlight at a maximum, the albedo effect is important and the fears that the low Arctic minimum of 2007 could lead to a progressive reduction in sea ice area were valid.

At the time of the TAR4 there was little information available on ice depth and volume. From October 1998 daily values of ice thickness are available from the US Navy polar ice prediction system(PIPS). The forecast values of ice thickness use weather forecasts, and buoys and ice concentration data from the Special Sensor Microwave Image (SSM/I) are used to initialize the system's forecast. The results are available as GIF images. A typical one is given below.

To derive areas and volumes the graphic images were downloaded analysed.  The projection used is not an equal area project so the areas derived were approximate. They were based pro-rata on a scanned image of Greenland. During the analysis it was found that the colours representing thickness range 0.5 to 0.75 were never present. It should also be noted that occasionally there were anomalous values, for example for a few days the Caspian and Aral seas were included.

The following graph shows the area and volume of sea ice from October 1998 to May 2010. These figures only apply for ice greater than 0.75 m thick and consequently the areas are less than those of ice extent in the above graph.

 In general the volume and area show similar variation but after the low summer minimum of 2007 the ice area recovered well in 2008 but the volume. This is reflected in the chart on ice thickness.

This shows that minimum ice thickness was less in 2008 than in 2007, giving some support to those who said the ice that year was “rotten”. It is interesting to note that the ice thickness is bi-modal; one maximum occurs in May when the ice area has just passed its maximum and the second in September near to the point when it is at its minimum. This can be seen more clearly in the following graph where compare average thickness with current ice thickness.

The shape of the graph suggests that ice thickness is belatedly reaching its spring maximum. How it will develop in the coming months is something we will follow with interest. What these graphs do show is that Arctic sea ice is recovering in terms of volume, are and thickness.

In these “theses” we generally do not concern ourselves with short term effects so to counter that remember that during the last inter-glacial sea levels were 6 m higher than at present.  Although melting sea ice does not affect sea levels we can none-the-less expect more melt independent of any anthropogenic effect. 

IPCC TAR5: The presentation of graphs data in TAR5 was biased to give an exaggerated impression of ice loss. In TAR5 the presentation should be more balanced. It should use a wider range of metrics to assess changes in sea ice.

IPCC Technical Assessment Report 5 – Thesis 2

Thesis: That the discussion of sea level rise in IPCC TAR4 has much to recommend as a model for other topics.

Those of you who have already seen our first thesis, on global temperatures, may have got the impression that we were out to ‘get’ the IPCC. This is not the case. We are self-financed and have no agenda. As we say on our Home Page: “We are trying to prove only one thing: rational debate is possible when participants have access to the facts.”

In TAR4 the increase in sea level is presented in the following graph.

This graph appears as Figure 3 in the Summary for Policy Makers and elsewhere (We have extracted the sea levels from a compound graph which also showed Global Average Temperatures and Northern Hemisphere snow cover). It combines levels from tide gauges (circular dots) and satellite measurements (the red line).

In the summary the accompanying text says: “Global average sea level rose at an average rate of 1.8 [1.3 to 2.3] mm per year over 1961 to 2003. The rate was faster over 1993 to 2003: about 3.1 [2.4 to 3.8] mm per year. Whether the faster rate for 1993 to 2003 reflects decadal variability or an increase in the longer term trend is unclear.” Similar words appear in the Technical Summary and the Synthesis report. What is commendable in this case is that even in the condensed Summary for Policy Makers there is no attempt to attach a high level of significance to the higher rate of sea level rise for the ten years preceding the preparation of the report.

The Technical Summary also states (Paragraph 3.3.3): “The tide gauge record indicates that faster rates similar to that observed in 1993 to 2003 have occurred in other decades since 1950.” This is supported by the following figure in Chapter 5 of the main report.

This contrasts markedly to the global temperature graph we discussed in the previous ‘thesis’. (http://www.climatedata.info/Discussions/Discussions/opinions.php?id=5404421343497121129 ).

There are two areas where the increase could be presented in a wider context in TAR5.

Firstly since TAR4 was written there is more evidence of sea level changes in the last couple of thousand years.

The blue crosses represent relative sea level rise for Vidarholmi in Iceland as calculated by Gehrels et al. No adjustment has been made for post glacial rebound but this is unlikely to have varied substantially over the period of the estimates. The figure before 100 AD may have been modified by compression in the salt marsh sampling area but even so the levels after that date suggest that recent rates of rise are by no means extraordinary.

The green circles show estimates of sea level on the coast of Israel calculated by Sivan and Toker. They are based on archaeological evidence from different broadly defined time periods (e.g. Hellenic or Crusader). The dating and levels are not given to a high degree of accuracy but also suggest that rapid sea level changes might have occurred in the past.

The red line, provided for comparison, is the increase since 1702 based on tide gauges by Jevrejeva et al. This confirms that the rate of sea level increase accelerated around 200 years ago and is not a recent phenomenon.

The second point is that in the previous interglacial sea levels were about 6 m higher than they are today and in other interglacial periods levels were from 3 m to 20 m higher. It is therefore possible than in coming centuries many coastal locations on earth might experience sea level rises of the same order of magnitude as those estimated by Sivan and Toker. That said there are many coastal cities in the world, such as Marseilles, Akko (Acre) and Naples, which existed well before the start of the present era and which have adapted to sea level changes.

IPCC TAR5: The TAR4 dealt with sea level changes accurately and in a responsible way. However the IPCC TAR5 could be improved by expanding information on the context of the projected level changes.

References:
Gehrels et al., Rapid sea-level rise in the North Atlantic Ocean since the first half of the nineteenth century. The Holocene 2006; 16; 949

Shivan and Toker, The Sea’s ups and downs. http://newmedia-eng.haifa.ac.il/?p=2330

Jevrejeva, S., J.C. Moore, A. Grinsted and P.L. Woodworth. 2008. Recent global sea level acceleration started over 200 years ago?, Geophysical Research Letters, 35

IPCC Technical Assessment Report 5 – Introduction

At the start of 2010 the IPCC attracted a lot of criticism for three projected climate change impacts which were poorly supported. These were that Himalayan glaciers might disappear by 2035, that African agricultural yields could fall by 50% and that 40% of the Amazonian rain-forest could react drastically to changes in precipitation. In each case the source of the claim was speculative and lacking sound evidence. The IPCC’s response was that in such a major series of documents it was well nigh impossible to avoid a few mistakes. To some extent this is true but the fact the errors all erred on the side of exaggerating the effects of climate change says much about the IPCC’s lack of balance.

We believe however that there are more serious criticisms which can be leveled against the IPCC.

Science is only as good as its data and in many cases the data presented by the IPCC tell only part of the story.

Since we are criticising the IPCC we should make out own position clear. So where do we stand? We believe that the science and data show unequivocally that temperatures today are higher than would have been case were it not for greenhouse gases emitted by human activity. On the other hand we do not believe that the more extreme forecasts of increased temperatures and their impact have been proven. We also believe that there are good reasons for reducing use of fossil fuels, of which effect on the climate is but one.

We also believe that climate modelling is important for the future. In the past, design of anything affected by weather, urban drainage or water supply for example, has been based on a statistical analysis of past data. It is now clear that a fundamental assumption of such analysis, that the events analysed are independent of each other, is invalid. To be able to predict natural and anthropogenic changes in climate should become the new paradigm for engineering design.

Our position, and that of those who have studied the science and share our views, is similar to that of Martin Luther, the 15th century reformer. He was, and remained all his life, a Christian but he thought that the activities and excesses of the Roman Catholic Church at that time were acting against the faith he accepted. We believe that there is a powerful analogy with the IPCC at the present time. Its performance is such that far from leading the population to accept their assertion that unless radical and immediate action is taking the world will suffer gravely they, by bias and distortion in their arguments, have left many people refusing to accept that humans have any influence on the climate.

Martin Luther put his case by pinning 95 Theses to the door of a church (today he would probably have been a blogger). What we are going to do is to publish a series of ‘theses’ where we highlight some aspects of the IPCC Technical Assessment Report of 2007 (TAR4) which could be improved in the next report (TAR5).

There remains one important question: Why should you believe us? The answer is you won’t have to. For reach of our theses we will give chapter and verse on the section of IPCC TAR4 we are commenting on and the source of the data we use to propose improvements.

Ian McEwan: Solar

This book has two features which differentiate it from the other books reviewed here: it is a novel and relatively unbiased on the topic of climate change.

Ian McEwan is one of Britain’s leading novelists. In interviews he says that he accepts the scientific view that climate change is taking place as a result of human activity. Some newspapers also reported that he had delayed publication of ‘Solar’ until after the Framework Convention on Climate Change Meeting in Copenhagen. From what I had read of his earlier novels I was expecting this novel to contain much wailing and gnashing of teeth but I was wrong. On the author’s web site the novel is described as “an engrossing and satirical novel which focuses on climate change”. I agree with that.

The main character, Michael Beard, won a Nobel Prize in Physics as a young man but he is now in his 50s treading water intellectually and trading on his reputation. He gives lectures and decorates various committees. Despite his unprepossessing appearance, baldness and excessive girth he is a serial husband and philanderer.

One of his appointments is as the one-day-week, figure-head, chief of a government initiative to tackle global warming. Initially showing only lukewarm interest in his sinecure, a combination of circumstances leads him to an awareness that photo-electrical interactions, his own area of expertise, could provide the ideal solution to clean, cheap, carbon-free energy. The book has a few factoids, which I have not checked, which underline his idea. A kilogram of gasoline contains 13,000 watt hours of electricity but the best batteries only store 300 watts hours per kilo. In other words, alternative energy sources have to compete with gasoline’s weight/energy ratio and avoid electrical storage. The third factoid is that the hydrogen in one litre of water has three times the energy of a litre of gasoline. Since hydrogen can be stored, unlocking it from water could provide the ideal clean source.

His route to this realisation is not straightforward. He is invited to join a group of artists concerned with climate change in a ship north (but only just) of the Arctic Circle which he is assured will be “toastily-heated”. One of the book’s great comic moments is when outside of the ship he stops to satisfy the needs of nature and discovers that at very low temperatures flesh sticks to metal zips. The irony of living in comfort, building ice-sculptures and riding snowmobiles to see vanishing glaciers as a protest against climate change is not lost on him.

While head of the government alternative energy centre, Beard decides to back a helical wind turbine for use on the roofs of private homes. The initial enthusiasm is soon worn down by health-and-safety concerns, current conversion and other problems which take teams of well-meaning but unproductive experts to examine in long and expensive detail.

As Beard's disorganised personal life impacts on his professional life, the invitations to lecture and to sit on boards become fewer and fewer. He starts to develop the idea of clean energy from water. To get development money he delivers a speech that Al Gore would be proud to a convention of investment bankers.

When the idea is getting closer to realisation, his business partner, whose seen a woman professor of atmospheric studies on television saying it is getting cooler, starts to wonder if people will still be willing to pay for alternative energy sources. Beard reassures his partner by saying :

'Here’s the good news. The UN estimates that already a third of a million people a year are dying from climate change. Bangladesh is going down because the oceans are warming and expanding and rising. There’s drought in the Amazonian rainforest. Methane is pouring out of the Siberian permafrost. There’s a meltdown under the Greenland ice sheet that no one really wants to talk about. Amateur yachtsmen have been sailing the North-West Passage. Two years ago we lost forty per cent of the Arctic summer ice. Now the eastern Antarctic is going… It’s a catastrophe. Relax!’


Remember, the author accepts that anthropogenic climate change is taking place yet here he is lampooning the tendency of ‘warmists’, to revel in bad news. The ‘deniers’ are no better; they are never happier than when airports are closed by snow storms and motorists are trapped by blizzards.

Despite the author’s beliefs he has the perspicacity to see participants from both sides, warts and all, in a clear objective way; if only those who write technical books on climate change were as perceptive about the science.

Author: Ian McEwan

Publisher: Jonathon Cape, 2010

ISBN: 9780224090490

Is Google biased in favour of climate change?

Google ranks pages from 0 to 10 using a page rank (named after Lawrence Page). The higher the rank the more likely is Google to send an enquiry to that page. Sites with the maximum rank of 10 include CNN.com and BBC.co.uk.

About a year ago my colleague and I set up links to the most popular climate change blogs, those with a Google page rank of 5 or above. We’ve just revisited the blogs and found that whilst changes to ‘non-sceptic’ blogs are fairly neutral (as many upgraded as downgraded) for ‘sceptic’ blogs there have been more downgrades than upgrades. The following table summarises the situation.

Site type Change Number Non-sceptic +1 9 Non-sceptic 0 23 Non-sceptic -1 7 Non-sceptic -2 1 Sceptic +1 2 Sceptic 0 25 Sceptic -1 10 Sceptic -2 3

The non-sceptic blogs are almost in balance with 9 up and 8 down; one has dropped by 2 places but that blog has only posted once since early December 2009. On the other hand only 2 sceptic blogs have increased but 13 of them have fallen, three of them by two points. Unlike the non-sceptic blog which fell by 2 points all three of the sceptic blogs which fell by 2 points had posted something new in the last few days, though one of them had moved its web site to a new address.

It cannot be a function of number of visitors. Alexa, the web information company, gives “Watts up with that” as the most popular climate blog and it has a page rank of 7. On the other hand “Realclimate” according to Alexa has had a quarter of the visitors to ‘Watts’ over the last 3 months but has a page rank of 8. “ClimateAudit”, which also has more visitors than “RealClimate” also has a page rank of 7.

There are also several non-sceptic sites which get less than one percent of the visitors of ‘Watts’ but have the same rank of 7.

The conclusion, unlikely as it may seem, is that Google does have a bias – against climate sceptics.

Postscript
As several people have pointed out on blogs where we have linked to this, and we ourselves were aware, Google's ranking system is complex, secret and changing. None-the-less it does seem strange that at a time when opinion polls suggests that sceptics are in the ascendant there should be a diminution in the their Google rankings.