So who can answer Jerry Pournelle's questions about Global Warming?

So, all those scientists who think otherwise, they have poor math skills, or are unfamiliar wth the meaning of the word “emprical”? Or did they fall victim to the liberal agenda?

C’mon, now…there’s no empirical facts to support anything of sufficient complexity. Operation of the brain/CNS? Nope. Just computer models.

Let’s play a game and and come up with some more. Bah! Silly scientists.

Inferno and the first Mote book were pretty good. Lucifer’s Hammer wasn’t bad.

I’d be more inclined to mark down as “Black Tuesday” the day Larry Niven decided he wasn’t interested in the heavy work of actually writing his stories anymore. Pournelle was simply Niven’s first ghost-writer.

In fact, while certainly not the cleanest way to get spacecraft into orbit, it’s not stupid per se. It would certainly work. It’s a concept that could be expanded and/or modified for manned exploration outside the moon’s orbit.

It’s a hypothesis, it is not fact. It is based on computer models that certainly do not take into consideration all of the variables. It may be an accurate hypothesis but it is far from fact.

Pournelle also can’t resist putting in political jibes in his fiction, like in the Inferno sequel where some anti-DDT scientists/activists are rewarded with a nice extended stay in Hell for their efforts, ostensibly because of all the human lives lost to malaria from the lack of spraying. Nevermind that keeping the stuff going would have meant a wholesale loss of many of our raptors (among with many other subtle nuances, like increased insect resistances over time). Weird thing is I don’t recall that kind of crap in the 1st novel, nor in his Galaxy columns, which I read religiously.

Of course, that’s not what you said, which was:

Bolding mine.

Not quite accurate but on the whole it is because Geo engineering is risky.

A better hypothesis is that many that take the contrarian position never learn from previous discussions.

Sorry, misread OP.

To be fair, regardless of the statistical likelihood of a large meteor impact (>1 km in diameter), the consequences for human civilization would be literally apocalyptic. Even a near miss might be seriously disruptive to telecommunications and geoobservation satellites, so even a trillion dollar pricetag might pay for itself for a single use. However, aside from basic space launch capability, the technologies used to deflect a large hazardous object and those proposed for the Strategic Defense Initiative are very different, and trying to backdoor justify SDI based upon meteor defense is disingenuous at best.

True that. Given enough data, you can even bootstrap your thin regions of data or (possibly) make valid extrapolations outside of the data set. The problem, especially for a complex system like climate, becomes one of interpretation: what does all this data mean, and what are the independent, covariant, and dominant parameters. There is no question that there is a clear and dramatic climate warming trend over the past 150 years, even given that we have sparse data outside of that range, and if Pournelle is saying otherwise he is either ill-informed or intentionally obtuse.

The question then becomes how much of this is due to anthropomorphic effects, and how much is part of the natural complex climate cycle. It seems awfully suspicious that the rise in overall temperature and increase in amplitude of seasonal variations occurs over the same period as industrialization, and while different global climate models tend to vary pretty widely in year-to-year predictions, nearly (if not all) show a global warming trend that corresponds to observation if CO and CO[sup]2[/sup] emissions are included in the model. While the hypothesis of anthropologically-caused warming can’t be falsified to a degree of scientific certainty, there is certainly an increasingly strong circumstantial case to be made that carbon emissions play a significant component into the warming trend. The degree to which they do, and the future response of the climate is still uncertain, as climate models are complex, readily perturbed systems. However, this same problem doesn’t prevent economists from making projections about market trends, or biologists from estimating population growth and decay, and using subsequent data to refine their models. Similarly, climatologists are plugging increasingly detailed measurements into their models and are obtaining progressively better agreement between prediction and future observations.

Stranger

It sounds to me that Pournelle is going for the now old “there is no warming or no warming with statistical significance”

That is at best a gross oversimplification.

  1. It is a fact that CO2 levels are rising.

  2. It is extraordinarily likely that the CO2 rise is due to human fossil fuel combustion. For a citation I give you Willis Eschenbach, strident climate skeptic and sometimes doper under the name intention. He is sufficiently skeptical of AGW that he has been accused of being a shill on this board, and yet his essays http://wattsupwiththat.com/2010/06/07/some-people-claim-that-theres-a-human-to-blame/ and http://wattsupwiththat.com/2010/06/04/under-the-volcano-over-the-volcano/ argue powerfully that the CO2 rise is real and caused by humans.

  3. It is a fact that increasing the CO2 level alters the energy fluxes in and out of Earth’s atmosphere, giving a warming effect. This is basic radiative physics, lab demonstrable over a hundred years ago. The effect is small, but it’s real. It’s small enough that if CO2 were the only thing we needed to worry about, then there wouldn’t be anything like as much pressure for action. Unfortunately, it isn’t. There are amplifying feedbacks, the strongest and most immediate of which is water vapour.

  4. It is a very safe prediction that increasing the CO2 level in the atmosphere will increase the absolute water vapour level. Exactly how much is not easily predicted, and most models simply hold the average relative humidity of the atmosphere fixed and account for temperature. Recent satellite measurements have confirmed that the water vapour level is rising as expected, but IIRC the average RH is falling so the water vapour feedback might not be as large as some models predict. It is still significant though.

  5. It is a fact that increasing the absolute water vapour level also alters the energy fluxes in and out of the Earth’s atmosphere, amplifying the warming effect of CO2. Corresponding changes in albedo due to cloud are not well modelled or even currently well measured however, introducing a fair amount of uncertainty into the total effects of increased water vapour.

  6. The net imbalance in energy fluxes in and out of the atmosphere is too small and noisy to be directly measurable, but it is very apparent in the eminently measureable, rising heat content of the oceans. The oceans have absorbed a truly scary amount of heat energy in the last thirty years or so. Warming has definitely happened, regardless of any doubts about the surface temperature records. There may be something of an unexplained hiatus in the rising heat content of the oceans at the moment, which is the subject of much research. See Trenberth and Pielke Senior’s dialogue here: Further Feedback From Kevin Trenberth And Feedback From Josh Willis On The UCAR Press Release | Climate Science: Roger Pielke Sr. Something interesting may come out of that in the next year or two.

  7. The IPPC’s estimates of climate sensitivity to CO2 ranges from around 1.5 - 6 degrees C for a doubling of CO2. These estimates do come from models, and the wide spread indicates that the models make different assumptions. Apart from clouds, some other poorly understood factors include the lag between heat accumulation in the ocean and surface temperature rise, and the amount of AGW being “masked” by sulphate aerosols. If the lag is small and the sulphate aerosols have a small effect, then the sensitivity will be in the lower range. The truth is we don’t have good figures for either yet, and the figures we do have support a sensitivity in the lower range of the estimate.

Syllogisms? :dubious: Aristotle’s Law of the Excluded Middle? :dubious: You’re just going to provoke the Flat-Earthers to conscript the great mathematican Brouwer into their camp, and deny Western logic. :smack:

I like the SDMB motto:

Taking longer because so much of the ignorance is willful. And because otherwise-intelligent humans imagine they need to find some blogger to double-check the statistical tests of a legion of physical scientists. :smack:

I guess I’ll defend Pournelle, even though I think he’s wrong about the basics of global warming.

No one has answered his question. The specific question involves measurement error and the reliability of historical temperature data. All other points about global warming are irrelevant for the purpose of this discussion.

wevets and Stranger on a Train are closest in staying on topic, but I think their arguments are invalid in this case. Both of them are making the assumption that the data points are random, and that there is no common-mode error.

But consider the following possibilities:

  1. Areas with the earliest temperature monitoring are likely to have undergone significant industrial/human development near them, causing an ‘urban heat island effect’ that causes a common-mode trend error towards heating.

  2. Data may be cherry-picked. That’s certainly the criticism against tree-ring data, which critics claim is an artificially small sample set because the larger sample of data does not show the same temperature and thus does not support the conclusion

  3. The technique of smoothing the data by gridding the measurements and virtually moving them on the grid creates a common mode error by shifting more temperature points north. In addition, the creation of virtual stations hides the fact that some of the data is actually very sparse, as in only one temperature monitoring station existing for hundreds or thousands of miles.

  4. The placement of temperature stations is not consistent in altitude, and there may be common mode bias in the data if stations are more likely to be put at lower altitudes and then ‘gridded’ to a higher average altitude, due to atmospheric temperature lapse rate.

  5. There are really two eras in the measurement data: One in which there were actual man-made temperature monitoring stations, and another in which the temperature has to be determined by proxy (tree rings, historical accounts of ice changes, etc). The latter area is, as far as I can tell, based on extremely thin data. A tree ring sample from a Russian forest, some ice core samples, and a few other things. There’s not even scientific agreement over whether the Little Ice Age was a global phenomenon, and it was a major temperature excursion. The data is just too thin.

  6. The data has been massaged/manipulated. One of the arguments the skeptics have made is that if the errors in temperature measurement were truly random, then adjustments made by gridding and other statistical techniques should result in as many temperature downgrades as upgrades. But in fact, it seems that most or all of the adjustments that have been made have resulted the entire dataset moving in one direction. That seems suspicious. Maybe not intentional fraud, but observer/confirmation bias making its way into the data. For example, if you already believe that global warming is real, and you’re in charge of filtering out ‘bad’ historical data or coming up with algorithms to smooth it, you may be more willing to look critically at data that doesn’t fit the model, or more willing to accept flawed analytical techniques that support it.

Because the original data is noisy, discontinuous and not randomly sampled (at the least, more temperature stations will be found in areas with more human activity), these types of errors may be harder to spot.

I’m a little bit baffled that Pournelle is a denier. After all, a primary underlying idea in Niven’s Known Space stories is that civilizations can rid themselves of every waste product except heat. The idea that overindustrialized worlds would need a way to lower their temperature seemed instantly obvious to science fiction readers and writers at the time. True, he meant heat heat inevitably produced by energy used for work, rather than a greenhouse gas emission problem. We have that problem too, of course…to a small degree…look at any weather map and you’ll see it’s always a few degrees warmer in cities.

I’m using this next quote as a jumping-off point, not disagreeing with it:

Which leaves us with two courses of action:

  1. If it’s human-caused, we need to reduce our greenhouse gas output as much as possible to slow or stop the trend.

  2. If it’s a natural cycle, we need to reduce our greenhouse gas output as much as possible so as not to contribute to the trend and make it any worse than it’s already going to be.

This is one of the most important goals for us, and grows more important as the trend continues. The economy will certainly be poor if earth no longer supports human life. It might be a choice between:

  1. spending trillions of dollars and getting a highly desirable planet, or

  2. wasting all the money there will ever be and winding up with nothing.

Sam Stone wrote an excellent summary of temperature measurement errors. An additional point is that most of the Earth’s surface is ocean and most of our historical data concerning sea surface temperatures are limited to major trade routes and collected by people who were not trained meteorologists. NOAA has a summary here:

http://www.csc.noaa.gov/crs/cohab/hurricane/sst.htm

Even on land, there are huge parts of the Earth’s surface where we have a very limited temperature history. There are large parts of the interior of Asia and Africa where the temperature record might as well be blank and say “Here there be dragons”.

Our ability to measure the temperature of the Earth has improved enormously since 1980 with satellites collecting temperature data. Thermographic sensors are better suited to measuring the temperatures of areas rather than points and you are only dealing with a few instruments that are constantly being analyzed and calibrated.

In addition, in the last few years the Argo sea buoy system has been deployed which consists of over 3,000 buoy reporting temperature data from the ocean from the surface to 2000 meters.

http://www.argo.ucsd.edu/About_Argo.html

P.S. Speaking as someone who wore out his first copy of “The Mote in God’s Eye”, I have to strongly disagree with anyone who wishes Niven and Pournelle never met.

I have to say that is the fault of the OP by not pointing out the exact issue, Pournell is all over the map.

So far I have seen only innuendo and bad evidence when contrarians they say that the technique is misleading, in this case more than just their say so should be considered.

As mentioned before, the contrarians that say scientists are using extremely thin data are 100% wrong. Even in previous discussion it was pointed out that (specially the 2008 Mann one) other proxies were used in the reconstruction, including coral, boreholes and cave strata. You may had noticed that denialists almost never criticize the results obtained by the experts that got that other proxy data.

I still will have to see better evidence for that.
http://www.msnbc.msn.com/id/33482750/

And that is why the reconstructions do not depend on the tree rings alone as mentioned.

Science is all about refining the data and it is fair to point out places where error can creep in. In this case scientists have long since accounted for the Urban Heat Island (UHI) effect and found it to be a non-issue.

Not even sure what all the rest of that is pointing at except generic complaints.

Again, it is fine to point out weaknesses in data and how it is tabulated/correlated/massaged. Thing is I have yet to see a complaint actually debunk the larger notion of global warming. Every time a complaint has been leveled and an effort made to address the complaint the same answer keeps appearing…global warming is real. Global warming deniers are still seeking their smoking gun and in the meantime just cast endless obstacles and demand ever more stringent levels of “proof”. Presumably that level will one day rise to the, “You can’t even prove we exist,” level and they will declare victory; Descartes be damned.

Every complaint has not been addressed yet but the effort continues and, were I a betting man, I would not bet against this trend. The deniers’ track record is miserable to this point.

This was not a definitive study on anything. It talked about possible problems with a couple of methods.

My community just had a solar array shoved up it’s collective keyster by state mandate to the tune of $35K per houses served. Since the array only works during the day, that’s really a $60K price tag for power per house. Due to the short cycle life of solar cells it’s just really expensive landfill. Maybe some of it can be recycled but it’s still an incredible waste of money. We’re already transitioning to more efficient cars and the nuclear technology to replace coal burning plants is sitting on the shelf. If we truly want to take advantage of future electric cars then the only real alternative is to build REAL power plants and not a bunch of monuments to stupidity that only work part of the day or depend on variations in wind.

Beyond the normal course of technology that should be taking place the solution to reducing temperatures shouldn’t rest on the insistence that co2 is the cause. We could easily overspend on a bunch of feel-good technocrap and still have a problem with increased solar activity.

The solution is to use the technology we have know and pursue the most cost effective technology in the future to lower temperatures. It may be cheaper to scrub co2 from the air than re-engineering society not to produce it in the first place. What we’re doing now is the equivalent of removing anything that burns to prevent forest fires instead of adding fire more fighting equipment.

Hell, yeah, there is! Warmist Greencommies are secretly covering our all our glaciers with rock salt! :mad: