Saturday, May 03, 2008


An email from Paul Stevens []

I find it amazing that proponents of AGW can maintain a straight face while they say that Pacific temperature oscillations and the Atlantic meridional overturning circulation will have a cooling effect, and subsequently cancel out continued temperature increases over the next ten years.

If these effects can have that kind of impact, couldn't they have had an amplification effect on the preceding decades of warming? In effect, the last ten years of stasis in temperature increases, and the next ten years of cooling are natural, but the preceding 20 years of warming are all the result of humanity's society and technology.

Unbelievable. As a previous correspondent suggested, "I don't think that most climate modellers...can even blush anymore."


An email from Richard Courtney []

The issue is simple. It is like this: A horse-racing tipster predicted a horse would win the Derby, but that horse came last. Then, the tipster said he had amended his method and - using his amended method - he was confident that the same horse would win the Derby next year. Would anybody other than a fool believe him?

Now, compare that to the following: Several teams made climate models and all those models predicted global warming with increased atmospheric carbon dioxide concentration. None - not one - of those models predicted that global warming would peak in 1998 then stop for the following decade despite atmospheric carbon dioxide concentration increasing by ~5%. But that is what has happened.

Now, one team has amended their model so it shows the cessation of global warming in 1998. Their amended model predicts that global warming will re-start in 2015. Does anybody other than a fool believe them?


Comment by Prof. Brignell, a specialist in signal detection. Note what he says about chartmanship. Graphs can be made to lie and there are some egregious examples of it in Warmist "science". Using tiny units of measurement, for instance, can give an impression of change where there is only random noise. If, by contrast, one took the average global daily range in temperature as the unit, one would see a temperature chart that is totally flat. And why not take our normal experience of temperature variation as the unit? It's an extreme proposal but it highlights how arbitrary and yet how important are the units of measurement used

As we were saying only last month, the motto du jour is get your rationalisation in first. The latest wheeze among the doomsayers is that hell fire is being postponed. Of course, it would have been more impressive if it had been published before the recent decade of measurements showing no warming at all. As it stands, it is nothing more than a testament to the infinite tunability of computer models. The warmers are getting more and more like those traditional predictors of the end of the world who, when the event fails to happen on the due date, announce an error in their calculations and a new date.

There is a new tendency that seems to afflict both believers and deniers alike, waiting for the next monthly data point and trying to make deductions and forecasts from it. A single new data point on a noisy graph tells you nothing about the development of trends (See the example of What happens next? in this presentation, slides 28-30). Fundamentals, such as the Uncertainty Principle and the estimation of trends ensure that a single point in time tells you nothing about the evolution of processes. Like the official definition of recession, you don't know it has happened until after the event.

PhD training used to be about eliminating tendencies such as getting excited about a new data point and loading upon it all sorts of fantastical premonitions that it is unable to bear, but that was another age and besides the culture is dead.

Furthermore, there is nothing more depressing for a referee than to find the introduction of a filter of mine own invention, as happened with the revival of the hockey stick by a pseudonymous author analysing data from a prominent Urban Heat Island. It is in the nature of the beast that at a certain stage in our development, scientists fall in love with the sheer romance of signal processing and rush to adopt the latest technique of linear algebra, including filtering, but it is a sign of maturity to stick to well known and fully understood procedures. In particular, a new procedure requires an enormous amount of analysis just to see what it actually does. More often that not (as for example in the introduction of the coppock) the only effect is to enhance the outcome desired by the author at the expense of perspicuity.

One of the most absurd examples of chartmanship you are ever likely to see is the one supposed to indicate an uprising of the dreaded methane. Not only are the units of the ordinates parts per billion, but the suppression of the zero is as dramatic as you can find. What is to all intents and purposes a horizontal line is transformed into a portentous curve, but even then it is indicative of a saturating phenomenon rather than an evolutionary one. It transpires, however, that the whole "threat" depends on a wriggle of noise at the very end of the plot. It might well transpire eventually that the curve is rising, but this nonsense does not establish it by a long chalk. Alas poor science!



(By DENNIS T. AVERY, a senior fellow for the Hudson Institute in Washington, DC and the Director for the Center for Global Food Issues. He was formerly a senior analyst for the Department of State. He is co-author, with S. Fred Singer, of "Unstoppable Global Warming Every 1500 Hundred Years". His email:

Now it's not just the sunspots that predict a 23-year global cooling. The new Jason oceanographic satellite shows that 2007 was a "cool" La Nina year-but Jason also says something more important is at work: The much larger and more persistent Pacific Decadal Oscillation (PDO) has turned into its cool phase, telling us to expect moderately lower global temperatures until 2030 or so.

For the past century at least, global temperatures have tended to mirror the 20-to 30-year warmings and coolings of the north-central Pacific Ocean. We don't know just why, but the pattern of the last century is clear: the earth warmed from about 1915 to1940, while the PDO was also warming (1925 to 46). The earth cooled from 1940 to 1975, while the PDO was cooling (1946 to 1977). The strong global warming from 1976 to 1998 was accompanied by a strong and almost-constant warming of the north-central Pacific. Ancient tree rings in Baja California and Mexico show there have been 11 such PDO shifts since 1650, averaging 23 years on length.

Researchers discovered the PDO only recently-in 1996-while searching for the reason salmon numbers had declined sharply in the Columbia River after 1977. The salmon catch record for the past 100 years gave the answer-shifting Pacific Ocean currents. The PDO favors the salmon from the Columbia for about 25 years at a time, and then the salmon from the Gulf of Alaska, but the two fisheries never thrive at the same time. Something in the PDO favors the early development of the salmon smolts from one region or the other. Other fish, such as halibut, sardines, and anchovies follow similar shifts in line with the PDO.

The PDO seems to be driven by the huge Aleutian Low in the Arctic-but we don't know what controls the Aleutian Low. Nonetheless, 22.5-year "double sunspot cycles" have been identified in South African rainfall, Indian monsoons, Australian droughts, and rains in the United States' far southwest as well. These cycles argue that the sun, not CO2, controls the earth's temperatures.

Dr. Henrik Svensmark's recent experiments at the Danish Space Research Institute seem to show that the earth's temperatures are importantly affected by the low, wet clouds that deflect more or less solar heat back into space. The number of such clouds is affected, in turn, by more or fewer cosmic rays hitting the earth. The number of earthbound cosmic rays depends on the extent of the giant magnetic wind thrown out by the sun.

All of this defies the "consensus" that human-emitted carbon dioxide has been responsible for our global warming. But the evidence for man-made warming has never been as strong as its Green advocates maintained. The earth's warming from 1915 to 1940 was just about as strong as the "scary" 1975 to 1998 warming in both scope and duration-and occurred too early to be blamed on human-emitted CO2. The cooling from 1940 to 1975 defied the Greenhouse Theory, occurring during the first big surge of man-made greenhouse emissions. Most recently, the climate has stubbornly refused to warm since 1998, even though human CO2 emissions have continued to rise strongly.

The Jason satellite is an updated and more-accurate version of the Poseidon satellite that has been monitoring the oceans since 1992, picking up ocean wind speeds, wave heights, and sea level changes. Jason is run by NASA's Jet Propulsion Laboratory and a French team.

How many years of declining world temperature would it take now-in the wake of the ten-year non-warming since 1998-to break up Al Gore's "climate change consensus"?



The original of the article below includes lots of graphics and links

A paper published in scientific journal Nature this week has reignited the debate about Global Warming, by predicting that the earth won't be getting any warmer until 2015. Researchers at the Leibniz Institute of Marine Sciences have factored in cyclical oceanic into their climate model, and produced a different forecast to the "consensus" models which don't. But how will we know whether the earth is warming or cooling? Today, it all depends on the data source.

Two authorities provide us with analysis of long-term surface temperature trends. Both agree on the global temperature trend until 1998, at which time a sharp divergence occurred. The UK Meteorological Office's Hadley Center for Climate Studies Had-Crut data shows worldwide temperatures declining since 1998. According to Hadley's data, the earth is not much warmer now than it was than it was in 1878 or 1941.

By contrast, NASA data shows worldwide temperatures increasing at a record pace - and nearly a full degree warmer than 1880. The other two widely used global temperature data sources are from earth-orbiting satellites UAH (University of Alabama at Huntsville) and RSS (Remote Sensing Systems.) Both show decreasing temperatures over the last decade, with present temperatures barely above the 30 year average.

Confusing? How can scientists who report measurements of the earth's temperature within one one-hundredth of a degree be unable to concur if the temperature is going up or down over a ten year period? Something appears to be inconsistent with the NASA data - but what is it?

One clue we can see is that NASA has been reworking recent temperatures upwards and older temperatures downwards - which creates a greater slope and the appearance of warming. Canadian statistician Steve McIntyre has been tracking the changes closely on his Climate Audit site, and reports that NASA is Rewriting History, Time and Time Again. The recent changes can be seen by comparing the NASA 1999 and 2007 US temperature graphs. Below is the 1999 version, and below that is the reworked 2007 version.

In order to visualize the changes, I overlaid the 2007 version on top of the 1999 version, above, and a clear pattern emerged. The pre-1970 temperatures have been nearly uniformly adjusted downwards (red below green) - and the post 1970 temperatures have been adjusted upwards (red above green.) Some of the yearly temperatures have been adjusted by as much as 0.5 degrees. That is a huge total change for a country the size of the US with thousands of separate temperature records.

How could it be determined that so many thermometers were wrong by an average of 0.5 degrees in one particular year several decades ago, and an accurate retrofit be made? Why is the adjustment 0.5 degrees one year, and 0.1 degrees the next?

Describing this more succinctly, the 2007 version of the data appears to have been sheared vertically across 1970 to create the appearance of a warming trend. We can approximate shear by applying a small rotation, so I tried "un-rotating" the 2007 graph clockwise around 1970 until I got a reasonably good visual fit at six degrees.

What could be the motivation for the recent changes? Further examination of the NASA site might give us a clue as to what is happening.

NASA staff have done some recent bookkeeping and refined the data from 1930-1999. The issues has been discussed extensively at science blog Climate Audit. So what is the probability of this effort consistently increasing recent temperatures and decreasing older temperatures? From a statistical viewpoint, data recalculation should cause each year to have a 50/50 probability of going either up or down - thus the odds of all 70 adjusted years working in concert to increase the slope of the graph (as seen in the combined version) are an astronomical 2 raised to the power of 70. That is one-thousand-billion-billion to one. This isn't an exact representation of the odds because for some of the years (less than 15) the revisions went against the trend - but even a 55/15 split is about as likely as a room full of chimpanzees eventually typing Hamlet. That would be equivalent to flipping a penny 70 times and having it come up heads 55 times. It will never happen - one trillion to one odds (2 raised to the power 40.)

Particularly troubling are the years from 1986-1998. In the 2007 version of the graph, the 1986 data was adjusted upwards by 0.4 degrees relative to the 1999 graph. In fact, every year except one from 1986-1998 was adjusted upwards, by an average of 0.2 degrees. If someone wanted to present a case for a lot of recent warming, adjusting data upwards would be an excellent way to do it.

Looking at the NASA website, we can see that the person in charge of the temperature data is the eminent Dr. James Hansen - Al Gore's science advisor and the world's leading long-term advocate of global warming.

Data Sources

NASA and Had-Crut data are largely based on surface measurements, using thermometers. They both face a lot of difficulties due to contaminated data caused by urban heating effects, disproportionate concentration of thermometers in urban areas, changes in thermometer types over time, changes in station locations, loss of stations, changes in the time of day when thermometers are read, and yet more factors.

NASA has a very small number of long-term stations in the Arctic, and even fewer in Africa and South America. The data has been systematically adjusted upwards in recent years - as can be seen in this graph, reproduced below. Temperatures from the years 1990 to present have more than one-half degree Fahrenheit artificially added on to them - which may account for most of the upwards trend in the NASA temperature set.

Official difference between the publicly reported temperature and the original data from USHCN/NASA Satellite temperature data (UAH and RSS) is more reliable because it covers the entire earth - with the exception of small regions near the north and south poles. They use the same methodology from year to year, and the two sources tend to agree fairly closely. The downside of satellite data is that it only goes back to 1978.

Now back to the present. NASA temperatures for March 2008 indicate that it was the third warmest March in history, but satellite data sources RSS and UAH disagree. They show March as the second coldest ever in the southern hemisphere, and barely above average worldwide. (The northern hemisphere in March was split between a cold North America and a very warm Asia, causing temperatures in the northern hemisphere to be above average.) Data so far for April shows both hemispheres back on the decline, and April is shaping up to be an unusually cool month across most of the globe (Africa, South America, North America and portions of Europe and Asia).

Bottom Line

Both of the satellite data sources, as well as Had-Crut, show worldwide temperatures falling below the IPCC estimates. Satellite data shows temperatures near or below the 30 year average - but NASA data has somehow managed to stay on track towards climate Armageddon. You can draw your own conclusions, but I see a pattern that is troublesome. In science, as with any other endeavour, it is always a good idea to have some separation between the people generating the data and the people interpreting it.

Some good news moving forward was reported this week by Anthony Watts, who blogs at Watt's Up With That? USHCN has issued a press release indicating that they are upgrading their methodology and ending the practice of adjusting data upwards for future temperature readings. This will make the data more credible, though will not resolve the issues associated with growing urban heat islands or a lack of spatial coverage across the planet.

Bear in mind that warming and cooling concerns are nothing new, as this alarming bulletin reminds us -
The Arctic ocean is warming up, icebergs are growing scarcer and in some places the seals are finding the water too hot, according to a report to the Commerce Department yesterday from Consul Ifft, at Bergen, Norway. Reports from fishermen, seal hunters and explorers, he declared, all point to a radical change in climate conditions and hitherto unheard-of temperatures in the Arctic zone. Exploration expeditions report that scarcely any ice has been met with as far north as 81 degrees 29 minutes. Soundings to a depth of 3,100 meters showed the gulf stream still very warm. Great masses of ice have been replaced by moraines of earth and stones, the report continued, while at many points well known glaciers have entirely disappeared. Very few seals and no white fish are found in the eastern Arctic, while vast shoals of herring and smelts, which have never before ventured so far north, are being encountered in the old seal fishing grounds.

A RealClimate blogger? No, that was the US Weather Bureau in 1922.

We saw a global cooling scare in 1924, a global warming scare in 1933, another global cooling in the early 1970s, and another warming scare today. The changes the USHCN promised Watts won't help resolve anything for another decade or so, but perhaps future generations will be able to reduce the alarming increase in the number of climate alarms.



As if the politics of addressing global climate change weren't already daunting enough, a new paper published in Nature this week suggests that the Northern Hemisphere, where most of humanity lives, could be due for a cooling trend, thanks to shifting ocean currents. Coming at a time when the idea of global cooling has been making the rounds on the internet, the prospect of a break in the observable warming trend greatly complicates the task of policy makers who are answerable to their electorates. It would be much harder to contemplate jarring changes to the economy to reduce greenhouse gas emissions, if the polar ice were to stop retreating and glaciers stabilized, or even began to grow again.

The new prediction is based on modeling work described in today's New York Times. It also prompts comparisons to predictions that global warming might trigger even more dramatic cooling, by altering the strength and path of the Atlantic thermohaline current, or "salt conveyor". Once again, we are reminded that global warming has always been a highly imprecise term for the complex processes now at work. That's why I prefer "climate change"--not as a euphemism, but as a more accurate description of the outcomes we face. Some even prefer "global weirding."

But while environmentalists may embrace this new scientific view of climate change as more volatile than the steady warming many have expected, climate skeptics will see it as a glaring inconsistency, particularly if the global rise in temperature stalls. That matters because it seems unlikely that the public's growing worries about climate change result from having absorbed the scientific consensus embodied in the reports of the Intergovernmental Panel on Climate Change (IPCC), rather than from media coverage of melting icecaps, shrinking glaciers, unusual heat waves and droughts, and the other evidence that fits a pattern of warming. If the visible evidence began seriously to diverge from that trend, I am skeptical that faith in science would sustain the public concern that must underpin any serious regulatory efforts, whether we're talking about emissions cap and trade, a carbon tax, or even the milder sector-specific targets that the President recently proposed.

Those who approach climate change with a quasi-religious fervor are likely to become apoplectic at any suggestion that a few cooler months or years might derail the growing policy momentum to institute the means of dramatically reducing emissions. But while they might be comfortable dismissing out of hand a winter that was 0.5 degrees Celsius colder than the previous one--punctuated by a sharp rebound in March--the rest of us might prefer a polite and practical conversation about how such variability could still be consistent with the overall trendline. Ultimately, our understanding of climate change must always remain incomplete, and so we must remain flexible enough to incorporate the new knowledge we will inevitably turn up along the way. Isn't that the essence of science?


Uncertainty is the only certainty

Comment from Australia by former Leftist politician Michael Duffy:

Global warming stopped six years ago. It might start again tomorrow, but from 2002 until now, average global temperatures have remained fairly constant. This is in contrast to the previous period when, as everyone knows, the temperature trend was upwards. Most people I've mentioned this to were not aware of it. They assumed that temperatures had continued to rise in line with greenhouse gas emissions, which have certainly continued to increase. So it's worth looking at what's happened.

The two most prominent organisations that record global average temperatures are the British Met Office's Hadley Centre and America's National Climatic Data Centre. Their records might be called "official"- Hadley, for instance, is closely involved with the Intergovernmental Panel on Climate Change. Their records for temperature change can be found at their websites. Hadley expresses temperature changes in terms of deviations from the 1961 to 1990 average. In 2002 the rounded global temperature for land and sea was 0.46 above that average. In the next five years it was: 0.46, 0.43, 0.48, 0.42, and 0.40. The figures for the data centre are calculated slightly differently, but they too show no trend over the period in question.

What does this mean? Some global warming sceptics say these figures disprove the basic hypothesis of global warming, that rising greenhouse gas emissions automatically produce rising temperatures. Some have looked back to 1998, an unusually hot year (0.52 on Hadley's list) and said that global warming actually stopped back then. They conclude that after 10 years we can now say global warming is over, and we face the possibility of global cooling.

I suspect it's still too early to make these conclusions. As a sceptic on this issue, I've spent years arguing that we just don't know enough about what's going on to predict the future with any certainty. It's too soon to junk that caution based on six (or even 10) years' data and claim that global warming is over. The earth might start to cool next year (not necessarily a pleasant thought, incidentally), it might stay the same, or it might start to warm again. I don't think any of us knows.

This is the argument that has been put by some on the other side of the issue. Some have also suggested that the warming trend has actually continued, despite the above figures. A good source for this position is the paper Waiting For Global Cooling, published last month by Robert Fawcett and David Jones of the National Climate Centre at the Australian Bureau of Meteorology. They say that the El Nino effect boosted the temperature for 1998, while the recent La Nina suppressed it, thereby masking the underlying trend. According to them, "the linear trend in globally-averaged annual mean temperatures . over the period 1998-2007 remains upward". This conclusion depends on the way they have used the raw data to calculate their trend line. As so often in the global warming debate, much depends on which data you look at and what you do with it.

Whatever the recent figures might signify, it's disturbing that they haven't received more publicity. If the trend had been different - if warming had accelerated, say - you can bet it would have been reported everywhere. But because the figures since 2002 might raise doubts about the orthodoxy, there has been a great silence. Most of those involved in public discussion of global warming simply ignored what was happening to the temperature record. The media have continued to interpret any minor weather event as proof of global warming. Political leaders have continued to crank up the panic. It's a response that has to raise concerns about the relative roles of reason, emotion and propaganda in public consideration of global warming.

The implications of the past six years for public policy are the same as for science: we need to be cautious. We simply don't know enough about this matter to justify urgent and dramatic action. It's worth reflecting on the number of scientists who are certain about what the temperature trend will be in a 100 years, yet in 2001 were unable to predict what would happen in the next six.



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1 comment:

OBloodyHell said...

> It's worth reflecting on the number of scientists who are certain about what the temperature trend will be in a 100 years, yet in 2001 were unable to predict what would happen in the next six.