Feb 222010
 

It was a rare night-time landing, but Endeavour is safely back home. The sight of an open flame from that venting on top, only visible at night, is positively weird: combined with the sound effects, it’s as if it was an overheated steam locomotive, not a space plane huffing and puffing on that runway.

Four more Shuttle flights to go, one of them by Endeavour. After that, for the first time since the 1960s, the United States will have no manned space flight capability. Hopefully not for long.

 Posted by at 3:30 am
Feb 182010
 

What a remarkably boring weather forecast:

I wonder if I am allowed to extrapolate from this trend and conclude that the temperature will remain -1 degrees Centigrade, like, forever.

 Posted by at 4:11 am
Feb 172010
 

While it may not feel like it if you live in the US or Western Europe, this has been a very warm January, the fourth warmest on record:

It was certainly warmer than usual (and a lot dryer than usual!) up here in Ottawa. Not that I am complaining.

Some proponents of anthropogenic global warming will point at this result as proof that global warming is “scientific fact”. The plot tells a more nuanced story. In the short term (last 8 years or so) there’s no warming trend at all, if anything there has been slight cooling. Prior to that, there was a roughly 30-year warming period. One other warming period that is very similar in nature occurred in the early half of the 20th century. In between, there was some cooling, just not enough to offset the earlier gains, hence the more recent warming period started with an already higher temperature, and we see an overall warming trend across the 130-year span of this plot.

But is that really a long term trend? Or is it just another periodicity that we simply cannot discern because the data set it too short in duration? This is the question that those “proxy” temperature estimates from tree rings, ice cores and whatnot are supposed to answer. How reliable are those? How representative? That is a key question, which may determine, for instance, if the infamous medieval warm period was comparable to the current warming or not.

 Posted by at 8:55 pm
Feb 152010
 

Someone just called my attention to this BBC interview with Phil Jones, director of the Climatic Research Unit (CRU) at the University of East Anglia (UEA), which has been at the center of the Climategate e-mails.

It has been suggested that Jones admitted that there has been no global warming since 1995, or that he made an amazing retreat. So I was curious as to what he actually said. Here are a few tidbits, hopefully not taken out of context:

Q. Do you agree that according to the global temperature record used by the IPCC, the rates of global warming from 1860-1880, 1910-1940 and 1975-1998 were identical?

A. […T]he warming rates for all 4 periods [NB: Jones counted 1975-1998 and 1975-2009 as two separate periods] are similar and not statistically significantly different from each other.

Q. Do you agree that from 1995 to the present there has been no statistically-significant global warming?

A. Yes, but only just. [… The] trend (0.12C per decade) is positive, but not significant at the 95% significance level.

Q. Do you agree that from January 2002 to the present there has been statistically significant global cooling?

A. No. […] The trend this time is negative (-0.12C per decade), but this trend is not statistically significant.

Q. There is a debate over whether the Medieval Warm Period (MWP) was global or not.

A. There is much debate over whether the Medieval Warm Period was global in extent or not. The MWP is most clearly expressed in parts of North America, the North Atlantic and Europe and parts of Asia. For it to be global in extent the MWP would need to be seen clearly in more records from the tropical regions and the Southern Hemisphere. There are very few palaeoclimatic records for these latter two regions.

Of course, if the MWP was shown to be global in extent and as warm or warmer than today (based on an equivalent coverage over the NH and SH) then obviously the late-20th century warmth would not be unprecedented. On the other hand, if the MWP was global, but was less warm that today, then current warmth would be unprecedented.

Q. If you agree that there were similar periods of warming since 1850 to the current period, and that the MWP is under debate, what factors convince you that recent warming has been largely man-made?

A. The fact that we can’t explain the warming from the 1950s by solar and volcanic forcing […].

Q. When scientists say “the debate on climate change is over”, what exactly do they mean […] ?

A. […] I don’t believe the vast majority of climate scientists think this.

Meanwhile, another error in the IPCC report has been uncovered, this one about the size of the Dutch countryside that is under sea level (26%, not 55%). An inconsequential error by itself, but apparently, it was enough for Robert Watson, former IPCC chief, to call for an investigation of this apparent bias, namely that all the errors uncovered so far exaggerate the presumed magnitude and effect of the warming.

So who can we believe? I don’t want to join the climate skeptics (at the very least, not without getting a hefty retainer from an oil company first!) but obviously, the choir hasn’t been completely honest with us either. What does the raw data say? Well, according to the UK Met Office, there has been warming in the last 160 years:

However, if I accept the short-term trend as just that, short-term, what we’re left with is a long-term warming of about 1 degree over 160 years… which is about 0.06 degrees per decade, about half the decadal figure during the last (1975-2002) warming period, a period that is by no means unique, according to Jones.

So… what am I to think?

 Posted by at 2:44 am
Feb 142010
 

A few months ago, a paper came to my attention; one written by a Hungarian climate scientist who supposedly resigned from his NASA job because he felt he was being muted by the climate science establishment. The paper was eventually published in a rather obscure journal, the quarterly journal of the Hungarian Meteorological Service. This paper has since been touted by its proponents as proof that the established climate models are bogus and that global warming is a hoax; on the other hand, it has been maligned by its critics, who declared it as junk science.

One notable point in Miskolczi’s paper is an unorthodox use of the virial theorem, and the funny thing is, while what he is doing is rather problematic, his critics fare no better; I’ve not seen anyone offer a technically correct analysis as to when the virial theorem might be applicable to describe a planetary atmosphere. (As a matter of fact, it is, but that doesn’t necessarily vindicate Miskolczi’s analysis.)

Miskolczi’s key result is that the atmosphere is in equilibrium in the sense that the greenhouse effect is already maximal; and so long as an effectively infinite reservoir of a potent greenhouse gas (water vapor) is available, this balance cannot be destroyed by changing the amount of CO2 in the air. However, this result may very well be a consequence of some trivial algebra that follows from some of Miskolczi’s more debatable assumptions.

In his paper, Miskolczi presents a model of the atmosphere graphically:

Without going into excessive detail (which can be found in Miskolczi’s paper), one can easily write down several equations from this diagram alone. First, Miskolczi asserts that P = P0 = 0, so that branch can be ignored altogether. We then have:

AA + K + F = ED + EU,
ST + EU = OLR,
F0 = OLR (the system is in equilibrium),
F0F + ED = SG + K,
SG = ST + AA.

To these equations, Miskolczi adds the following:

SG = σTs4 (Stefan-Boltzmann law describing a thermal blackbody surface at temperature Ts),
AA = ED (a much debated application of Kirchoff’s law by Miskolczi, his Eq. 4),
2EU = SG (Miskolczi’s application of the virial theorem),
SGF0 + EDEU = OLR (Miskolczi’s energy conservation formula, Eq. 7).

Now the thing is, at this point we actually have 9 equations in the 9 unknowns AA, K, F, ED, EU, ST, SG, F0 and Ts. Although the equations turn out to be not completely independent, only K remains undetermined; in particular, Ts is uniquely determined as

Ts = (3OLR / 2σ)1/4.

Now OLR = F0 = 238 W is known from observation, as it can be calculated from the solar constant and the Earth’s albedo. According to Miskolczi’s algebra, then, the only surface temperature consistent with this is Ts = 281.7 K or about 8.5 degrees Centigrade. This value is uniquely determined without knowing anything about the composition of the atmosphere other than its albedo.

If only climate science were this simple.

 Posted by at 4:27 pm
Feb 142010
 

Something I heard a few days ago on The Big Bang Theory:

“Where in this swamp of unbalanced formulas squatteth the toad of truth?”

What can I say… I know the feeling rather well.

 Posted by at 4:08 am
Feb 042010
 

Steven Weinberg has an opinion piece on the Wall Street Journal Web site, where he expresses confidence that Obama’s NASA budget is the right one. Instead of wasting money on a manned space program that is self serving (i.e., other than putting men in space, it accomplishes nothing) more money will be available for doing real science, he thinks.

He has a point… but, well, but there is a but. Science is an important goal of the space program, but it’s not the only goal. As a matter of fact, if you ask me as a taxpayer why I think it’s a good idea to spend some tax dollars on the space program, scientific research is just one of the reasons I’d mention, and not even necessarily the first reason. People should travel in space because our future is in space. The steps we’re taking today may be baby steps, but they’re still important steps… even if a future with colonies on Mars, manned exploration of the outer planets and their moons, or perhaps travel beyond the solar system is decades, if not centuries away.

Having said that… the Constellation program, effectively repeating the accomplishments of Apollo with slightly upgraded hardware, may not have been the smart thing to do even if it had been funded right, which it wasn’t. Another footstep on the Moon is not the same as sustainable manned deep space exploration. If I recall, one of the Augustine commission’s suggestions was a deep space program without a specific landing objective; one that focuses on developing capabilities more than achieving spectacular “footstep-and-flag” milestones, “landing” only on asteroids, if at all, focusing instead on long-duration flights in deep space. If this is the space program Obama’s administration is about to establish, who knows? Perhaps he’s putting the space program on the track that it should have been put on decades ago. (Then again, perhaps I’m just an incurable optimist.)

As a footnote of sorts, I find it noteworthy that, more than 50 years after Sputnik, there is still only one nation on Earth with a comprehensive deep space research program: the United States. Much of the Soviet space program died an undeserved and premature death after the collapse of the Soviet Union; as to China, India, Japan, the EU and other nations, their efforts are commendable but that still leaves them in the “also ran” category.

 Posted by at 1:46 am
Jan 312010
 

This is becoming more than a little annoying, to be honest. First, there were the Climategate e-mails. Then, the claim about Himalayan glaciers. Now the latest: according to the Daily Telegraph, claims made in the IPCC report about vanishing ice in the Andes and the Swiss Alps were based in part on a popular magazine, in part on the dissertation of a Swiss student who interviewed mountain guides.

And this is supposed to be the foundation for a multi-trillion dollar shift in the world economy in the coming years?

To be clear about it: I am not a “climate change denier”, disgusting as I find this term implying some kind of analogy between genuine scientific skepticism and things like Holocaust denial. Questions raised by Climategate notwithstanding, I do believe the data, and the data show that there was warming in the past several decades. However, the IPCC report was supposed to go much further, and provide answers to some very clear questions. Namely 1) is there a long-term warming trend? 2) is it due to CO2? and 3) is it bad for you?

These are not easy questions to answer. The long-term warming trend that might exist is hidden behind noise: large year-to-year fluctuations, the 11-year solar cycle, other longer-term cycles. The data may perhaps be equally well fitted by a model that proposes a long-term cooling, but medium-term fluctuations which caused the current warming cycle. Here’s where the second question comes in: the model should not be a mathematical mind game but firmly rooted in physics. Do we know the physics well enough? Knowing the cause is also important if we wish to reverse the effects… if we misunderstand the physics, all our efforts to reduce CO2 emissions will be in vain, while we ignore the real causes. And even assuming that the physics is clear and the models are reliable… why is warming such a problem? Sure, ocean levels will rise a little and some cities may have to move in the coming century… on the other hand, for instance, how about vast stretches of tundra that become fertile and can be used to fed the planet’s growing population?

The IPCC gave us firm conclusions. Yes, there is a long-term warming trend. Yes, it is due to anthropogenic CO2 (hence it can be reversed by reducing CO2 emissions). And yes, all things considered, it is very bad for us. But… If the IPCC’s conclusions on these questions are based on sloppy research, why on Earth should I believe them? Is it something like Pascal’s wager, because we have nothing to lose and everything to gain by betting on the IPCC being right? I’m sorry but I don’t buy that just as I’m not buying Pascal’s original argument either… I’d rather end up in Hell as a virtuous pagan than as a hypocrite.

 Posted by at 2:12 pm
Jan 222010
 

Here’s a nice tennis ball, photographed from both sides:

It’s a big one, mind you, almost a thousand miles across. It’s Saturn’s moon Iapetus, famous because one side of it is significantly brighter than the other. The explanation, however, is more mundane than that offered in the book version of Clarke’s 2001: A Space Odyssey; the most recent hypothesis is that the discoloration is due to the thermal migration of ice.

 Posted by at 7:44 pm
Jan 212010
 

Just when you thought Climategate was bad enough already, here’s another little tidbit.

Back in 1999, New Scientist published an interview with Indian climate scientist Syed Hasnain about melting glaciers in the Himalayas. In this interview, Hasnain speculated that “all the glaciers in the central and eastern Himalayas could disappear by 2035 at their present rate of decline”.

Fast forward to 2007 and the (in)famous Intergovernmental Panel on Climate Change report, which states that “Glaciers in the Himalaya are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by the year 2035 and perhaps sooner is very high if the Earth keeps warming at the current rate.” The source? A 2005 report by the World Wildlife Fund, which, in turn, quotes the New Scientist: “The New Scientist magazine carried the article ‘Flooded Out – Retreating glaciers spell disaster for valley communities’ in their 5 June 1999 issue. It quoted Professor Syed Hasnain, then Chairman of the International Commission for Snow and Ice’s (ICSI) Working Group on Himalayan Glaciology, who said most of the glaciers in the Himalayan region ‘will vanish within 40 years as a result of global warming’. The article also predicted that freshwater flow in rivers across South Asia will ‘eventually diminish, resulting in widespread water shortages’.”

So, it appears that a popular science magazine was the primary source for such a dramatic statement. The assertion that Himalayan glaciers might disappear by 2035 was never published in a peer reviewed journal. Worse yet, note how the statement became inflated over time: whereas the original article spoke of “all the glaciers in the central and eastern Himalayas”, the WWF translated this into “most of the glaciers in the Himalayan region”, and by the time this gloomy prediction got into the IPCC’s report, it read simply, “”Glaciers in the Himalaya”.

Now New Scientist is taking them to task, leaving many to wonder: is this really representative of the quality of the science on which dire global warming predictions are based?

For the record, while glaciers in the Himalayas may suffer from global warming, they’re not (yet) in danger of disappearing anytime soon. Certainly not by 2035.

 Posted by at 3:53 am
Jan 122010
 

I just finished a neat little paper with John Moffat. Jordan-Brans-Dicke theory is a generalization of relativity theory, in which the gravitational constant becomes variable, and the resulting (scalar) field has kinetic energy. First described by Pascual Jordan in his 1952 book Schwerkraft und Weltall, it was perhaps the first serious, “modern” modification of Einstein’s gravity. Yet it is rejected in the solar system, because it predicts an observable parameter that is grossly out of whack with observation. Then again… in the original form, the scalar field arises as a result of changes in spacetime curvature, only indirectly responding to the presence of matter. If we add matter as a direct source, the picture changes. Even more interesting, if matter and curvature kind of cancel each other out, we get a (still variable, still dynamical) scalar field that’s just like a field in vacuum, and agreement with solar system observations is restored.

Incidentally, Pascual Jordan was one of the greatest 20th century German physicists. Unfortunately he was also an ardent Nazi, member of the NSDAP and an SA volunteer. This may have been the reason why he never received the Nobel prize. Goes to prove that politics and science are really not a very good mix.

 Posted by at 4:04 am
Jan 012010
 

This is the year when the Soviet spaceship Alexei Leonov was supposed to fly to Jupiter, investigating the failure of the spaceship Discovery and the death of her crew nine years earlier. At least in one respect, Clarke’s vision will come true: after the Space Shuttle’s planned retirement later this year, the United States will be left without a manned launch capability, and American astronauts will be ferried to the International Space Station (alas, a mere few hundred kilometers above the Earth’s surface, not a billion kilometers from here like Jupiter) on board Russian spacecraft. Not exactly an inspiring thought, except perhaps to some Russians.

 Posted by at 6:21 am
Dec 292009
 

There is a fascinating book published by the RAND Corporation, available at Amazon for a mere 81 US dollars. I am tempted to buy it. It must be a fascinating read. Readers’ comments at Amazon are certainly encouraging; while the book has some minor flaws, despite the lack of serious proofreading it is guaranteed not to contain any errors, and it helped at least one reader get to meet the woman who eventually became his wife.

 Posted by at 3:42 pm
Dec 172009
 

I’m reading an opinion piece in last week’s New Scientist, by Michael Le Page and Catherine Brahic. It’s titled, “Why there’s no sign of a climate conspiracy in hacked emails”. It is intended to reassure us that “Climategate” notwithstanding, we should trust the basic science. Yet I feel that it misses the point on all counts.

Take the title, for starters. While I am sure there are conspiracy nuts out there who view the hacked e-mails as a smoking gun, I think many more people see a more nuanced picture: the e-mails prove no conspiracy, but they do demonstrate contempt towards dissenters and the general public, not to mention the scientific process, and they do raise questions about the validity of the so-called “scientific consensus” on climate.

But it’s not just the title that’s deceptive. The authors raise five points, in the form of questions and answers. At least that’s how the article appeared in print; on-line, two of the questions were turned into unambiguous statements, according to which we are “100% sure” that the world is getting warmer and it’s because of greenhouse gases as the main cause. No, we are not 100% sure. If you want to assign a percentage, then take the data, fit the models, and show us a covariance matrix that tells us exactly how sure we are that a long-term trend is present. Leave this “100%” nonsense to political activists.

The print edition stuck to the question-and-answer form. “How can we be sure that the world really is warming?” they ask, but it’s a misleading question: of course the world is warming, the real question is, how much of that warming is due to short/medium/long term natural periodicities, and how much of it is due to a more sudden (e.g., linear, exponential, etc.) trend that may be due to human activity. Do we have enough data to distinguish unambiguously (never mind 100%, 1-sigma can do nicely) natural fluctuations from more direct trends?

Then they ask, “How do we know greenhouse gases are the main cause?”, and assure as that “The physics is clear: carbon dioxide is a greenhouse gas, greenhouse gases warm the atmosphere, and CO2 is accumulating in the atmosphere.” This is pure nonsense of course, since I could just as well say something like, “urine is a liquid, adding a liquid to the oceans increases ocean volume, I keep peeing into the ocean, hence cities will be swallowed by rising sea levels”. Their answer sounds more like an attempt to divert attention away from genuine questions, such as those concerning the effectiveness of CO2 as a greenhouse gas (CO2 is a very weak greenhouse gas; for instance, if rising CO2 levels somehow reduced the amount of water vapor in the atmosphere, the net effect would be global cooling), the accuracy of models describing the effects of CO2 in the atmosphere (I’ve read a paper, for instance, that questions the ability of widely used physics models to deal properly with the discontinuity of the atmosphere-surface boundary), or the “chicken-and-egg” question concerning the climate record, namely the extent to which CO2 caused warming trends or rising temperatures caused an increase in CO2 during past warm periods.

Their third question reads, “So why are scientists ‘fixing’ temperature data?”, which they answer by explaining that raw data almost always has to be manipulated to correct measurement problems or reconcile measurements made in different ways. True. But that is no excuse to discard the raw data. Not to mention that the data manipulation that caught so many people’s attention in the Climategate e-mails was not about fixing up raw data… it was about using two incompatible sets of data to change the appearance of a fitted curve, lest it gives the wrong impression to a scientifically illiterate audience. They do address this issue separately in the on-line version, but the explanation they offer raises its own questions: for instance, they say that “there has been no attempt to conceal this”, but how does that reconcile with the phrase, “hide the decline”, quoted from the hacked e-mails?

Lastly, their final two questions are about the attempts to suppress skeptical papers and attempts to prevent data from being released. We’re told that an independent inquiry is still ongoing, and in any case, the scientists may not have had the right to release the data. That’s a non-answer. You don’t need an independent inquiry to explain how it is acceptable to “redefine the peer review process” just to keep skeptical papers out, and as to the data, how about answering the question insofar as it concerns data that they did have the right to release?

All in all, I could have come up with much better arguments myself… instead of attempting to side-step the questions, I’d have tried to address them. Data were manipulated because a fit indeed gave a curve that would give the wrong impression to the uninitiated, and adding the instrumental data to the fossil temperature record seemed like an honest “trick” to avoid this. Skeptical papers were suppressed because those involved may genuinely believe in their science, may genuinely believe that many of the skeptics are motivated by something other than pure scientific curiosity (especially if they happen to be financed by, say, a friendly neighborhood oil company), and may genuinely believe that we just don’t have time for this nonsense while the planet is heading towards a global disaster. Data were withheld because otherwise, all the time in the world would not be enough to deal with clowns who take that data, ignorantly (or nefariously) manipulate it, and come up with nonsense conclusions. These explanations may not justify the actions taken, but they might be closer to the truth in the end… and supposedly, truth and integrity are the only real currencies that science has at its disposal. Currencies which will be needed badly in the coming decades, in order to convince the inhabitants of Earth not to trash their planet beyond repair… regardless whether or not CO2 leads to global warming.

 Posted by at 2:43 pm
Dec 072009
 

41,000 tons of CO2 is the amount of “CO2 equivalent” that the Copenhagen climate summit is expected to produce. No, it’s not the amount produced by Switzerland in a year, even though CNN’s Jack Cafferty said so, probably missing the phrase, “thousands of” in the column heading of Wikipedia’s statistics. But it IS the amount of CO2 some smaller or less developed countries, e.g., Slovenia, Lithuania, or Kenya produce in a day. Another way of looking at it is that during its 12 days, the climate summit will be responsible for about 0.004% of the entire world‘s CO2 output.

No need to worry, I am sure there is a neat “trick” that can be used to “hide” this embarrassing little data point, too, lest it dilutes the message about the coming climate disaster.

 Posted by at 9:32 pm
Nov 252009
 

I’m still trying to digest this… the meaning of recently released e-mails that suggest, to put it mildly, questionable behavior on behalf of some of the world’s leading climate researchers.

One e-mail that’s most hotly debated is about this:

mbh99smooth_no_inst

This plot contains two types of data: long-term reconstructed temperatures from the fossil record, and shorter term instrumental temperatures. Now the trouble is, the smoothed curve (green) based on the reconstructed temperatures alone points slightly downward… no dramatic warming trend. In contrast, the instrumental temperatures show an upward trend. This apparent disagreement is purely a mathematical artifact; anyone who ever attempted to fit, for instance, a polynomial curve to some data knows that the fit tends to diverge near the ends of the data interval. But it wouldn’t look good on a report that is designed to influence world opinion and global policy to show a downward trend, would it. So there’s a neat “trick”: the apparent downward trend can be eliminated by using the instrumental temperatures to pad the reconstructed temperature data set, and produce an upward trend.

Note that this doesn’t mean that there is a downward trend. The planet may very well be warming, due to what people are doing to it. Unfortunately, the information content of manipulated graphs is zero, or less than zero even… they can generate skepticism towards genuine future results and delay a necessary public response.

There are many other questionable e-mails in the lot, including e-mails that suggest the hiding of data from freedom-of-information requests, e-mails that suggest efforts to block the publication of research by climate change skeptics, and at least one eyebrow-raising comment cheering at the death of a climate change skeptic, leading to calls for a researcher to resign.

I’m still digesting this, but it reinforces my conviction that phrases like “standard model” or “scientific consensus”, far from reassuring, should be a clear indication that the science might be shaky, and that an attempt is being made to substitute authority in place of convincing data and firm logic.

 Posted by at 4:35 am
Nov 132009
 

13Unlucky Friday the 13th it is not, at least not for NASA; they just announced that the much maligned LCROSS impact mission has, after all, found water on the Moon.

Does this mean that I might yet live long enough to see a permanent manned lunar base come into existence?

 Posted by at 8:25 pm
Nov 032009
 

Some Romanians are planning to fly a balloon to the Moon. OK, to be more precise, what they’re planning is the use of a stratospheric balloon as a launch platform for their attempt to win Google’s Lunar X Prize. It’s not as crazy as it sounds… the disadvantages of launching from an unstable platform like a balloon may be more than offset by the advantages of launching from an altitude that is above most of the Earth’s atmosphere.

 Posted by at 3:03 pm