Plea for good info on global warming

[Haelfix]

I'm a physicist, and a skeptic. I have been all my life.

Now, when it comes to global warming, I admit to not knowing a great deal. It seems that many in Academia feel that this is a legitimate threat. However, I have this growing suspicion about the integrity of many of these academics in the geo sciences. And frankly, that pisses me off, b/c there is no reason I should be doubting a fellow scientist at an accredited institution.

The thing that started rousing my suspicions, was when I was with a group of physicists who were debating fellow proffessors. The physicsists (who actually knew what they were talking about), were completely dismissive of the 'geos' viewpoints, and with good reason. Indeed, some of the fundamental physical equations the geophysicsists were using to model things were WRONG mathematically.

Upon talking with my colleagues, they informed me that the field was ripe with fraud, politics, money and excessive crap. Hell, read Freeman Dyson's thoughts on the subject (and there are few people alive I trust more implicitly)

So who am I to believe? Obviously the eqns are so complicated, it would be completely futile to expect anything definitive, but I am beginning to retreat into uninformed skepticism. Surely there are serious academics in the geo sciences who are proffessional and scientifically competent enough to make progress in the field. Its their viewpoints that I want... I'd love nothing more to hear an informed opinion, whether its pro/neutral/or con. But there is this trust issue.

Its times like this, where I often look for a review article which tries to be nonbiased, a cold hard technical centrist look at things.

 

[Bystander]

Google "global mean temperature" --- it's a thoroughly mixed bag; notably absent (as far as I've read through the pile) are lunar precession cycle-solar cycle and their product --- does include the odd mean sea level study --- but no explanation for 100 km³ over the past century beyond hand-waving appeals to density as function of T --- no bathythermography worth talking about --- no "figure of the earth" --- .

Hit NOAA for carbon dioxide and trace gas concentration-time maps. Bore hole temperature proxies have achieved "fad status" the last 5-10 years --- papers on method are few and far between --- can get you a couple citations with results --- results w'out method always raises questions.

 

[Ivan Seeking]

As per NOAA

The atmospheric carbon dioxide (CO2) measurements made at Mauna Loa Observatory, Hawaii, since 1958 provide strong evidence for human alteration of the environment (Fig. 16 ). The data through 1973 are from Keeling et al. (1982), while data since 1973 are from the National Oceanic and Atmospheric Administration (NOAA) program (Thoning et al. 1989).

Mauna Loa Observatory, located at an elevation of 3350 m on the flank of Mauna Loa volcano, is an ideal site for carbon dioxide measurements. There is no nearby vegetation, and the prevailing nighttime downslope winds give a representative sampling of midtropospheric air from the central North Pacific Ocean. Thus, this record is taken as a reliable index of long-term carbon dioxide growth.

The average CO2 concentration increase at Mauna Loa during the 1980s and 1990s has been about 1.4 ppm yr-1 but with significant year-to-year variability in this growth rate. The growth rate decreased to near 0.5 ppm yr-1 during 199293, increased to more than 2 ppm yr-1 during 1995, but then dropped in 1996 to near the average of the last decade in 1996. Contributing factors to these variations in growth rate include ENSO and the natural exchange of carbon dioxide between the oceans, the terrestrial biosphere, and the atmosphere.

http://www.cpc.noaa.gov/products/assessments/assess_96/tgases.html

1) Carbon Dioxide

After water vapor, CO2 is the most important infrared absorbing (i.e., greenhouse) gas in the atmosphere. Since the late 1800s atmospheric CO2 levels have increased approximately 30%, due primarily to emissions from combustion of fossil fuels and to a lesser extent from deforestation (Keeling et al. 1995). The total sink and the partitioning into marine and terrestrial components varies significantly from year to year (Conway et al.1994; Ciais et al. 1995). A better understanding of the processes that remove CO2 from the atmosphere and how these processes respond to climate fluctuations will enable better predictions of future CO2 levels, which will in turn decrease the uncertainty associated with models of future climate.

Current modeling approaches to understanding the carbon budget depend on atmospheric measurement data either as a constraint (carbon cycle models) or as input (inversion models). The latitudinal variation of atmospheric CO2 determined from the NOAA/CMDL Global Air Sampling Network for 1989–98, with the record from the South Pole shown in red (Fig. 70), conveys the long-term CO2 increase, the interhemispheric difference, and the seasonal variations of atmospheric CO2. Note that even though CO2 in the Northern Hemisphere is on average 3–4 ppm higher than in the Southern Hemisphere (because 95% of fossil fuel CO2 emissions occur in the Northern Hemisphere), the mean CO2 gradient is reversed during the northern summer because of photosynthetic uptake by plants. In contrast, the mean north-south gradient is strongest in spring when respired CO2 has accumulated in the atmosphere. Carbon cycle models attempt to reproduce this measured distribution by combining source/sink functions with atmospheric transport models, while inversion techniques combine the data with a transport model to deduce sources and sinks.

http://www.cpc.noaa.gov/products/assessments/assess_99/tgases.html

 

[Ivan Seeking]

Originally posted by Bystander
Hit NOAA for carbon dioxide and trace gas concentration-time maps. Bore hole temperature proxies have achieved "fad status" the last 5-10 years --- papers on method are few and far between --- can get you a couple citations with results --- results w'out method always raises questions.

Bore holes are a fad? Based on what?

Can you produce one paper published in a major journal that does not cite methods and sources?

 

[Bystander]

http://www.cmdl.noaa.gov/ccg/figures/figures.html
for the graphical results ---
http://www.cmdl.noaa.gov/ccg/figures/co2rug.jpg
is an example of the seasonal variation over the northern latitudes. This is a great one for the "warmers" --- and, it's also a great one for the "warmers are alarmists" --- see if you can figure out what's odd with the picture.

The use of bore hole temperature profiles as proxy temperature records has a perfectly reasonable theoretical foundation; the application of the theory to existing bores is a bit problematical --- there's no control of heat transfer up/down the bore. That is, the bore temperature profile is a modification of the matrix temperature profile, which is the real temperature proxy.

 

[Phobos]

Haelfix - Stick with the science organizations & avoid the political think tanks (on either side of the debate). I agree it's a tough issue to figure out - - both sides present good arguments. Heck, I'm an environmental engineer and I'm still trying to figure out what's going on. My current thinking is that adverse impacts resulting from human-induced global warming are a distinct possibility and, in this case, an ounce of prevention is worth a pound of cure.

 

[Ivan Seeking]

Originally posted by Bystander
This is a great one for the "warmers" --- and, it's also a great one for the "warmers are alarmists" --- see if you can figure out what's odd with the picture.

Dunno.

The use of bore hole temperature profiles as proxy temperature records has a perfectly reasonable theoretical foundation; the application of the theory to existing bores is a bit problematical --- there's no control of heat transfer up/down the bore. That is, the bore temperature profile is a modification of the matrix temperature profile, which is the real temperature proxy.

Introduction

The processes in the active layer and its connection to the atmosphere is of great importance for the state of the frozen ground below. These processes depend to a great extend on the actual material of the active layer (e.g. boulders, solid bedrock, gravel or soil) and the fieldwork should be designed with regards to what sub-surface is being measured. The here discussed procedures focus especially on active layer monitoring in areas of coarse boulders which usually covers considerable parts of the high alpine environment. Two main procedures are considered. One simple and quit cheap; the other more sophisticated and definitely more expensive and difficult to complete.

In bore hole palaeoclimatology, it is commonly assumed that a direct coupling exists between air and ground temperatures. This assumption is valid only if variables affecting ground-surface temperature exchange have remained constant through time. It should therefore be taken into awareness that ground temperatures can contain non-climatic noise due to changes in ground-surface variables, including vegetation cover, duration and thickness of snow cover, precipitation and melt water, wind speed and thereby wind pumping within the boulders, net radiation, phase change and boundary conditions. All this, as well as if one measure site or a network of sites is necessary should therefore be considered when designing the fieldwork in proportions to what is expected to be evaluated from the data.

Processes which influence the temperature regime within the active layer has been discussed in the literature (e.g. Williams and Smith, 1989; Humlum, 1997; Humlum, 1998; Harris and Pedersen, 1998; Kane et al., 2001; Hinkel et al., 2001; Schmidt et al., 2001)




Miniature temperature data loggers (mini loggers)

Mini loggers can be used as a simple and cheap approach when establishing a temperature profile above and within the active layer. The mini loggers are described in detail elsewhere in this publication. The mini loggers can normally be programmed to measure and store data at a variety of time spans and are simply placed with the desired spacing within the boulders. Mini loggers, though do not have endless memories and the more often temperatures have to be registered the shorter the time the mini loggers will be operating. Further disadvantages are that the batteries have to be replaced to not loose data and that the resolution of the data often is quite coarse.



Bore hole and thermistor chain

The system recording the data using this approach consists of the thermistor sensor chain, lowered in a bore hole, and connected to a data logger and a storage module normally driven by a battery or a solar panel. The data logger is the brain of a data acquisition system. They do the measurements at a specified scan rate and process the data. The data logger needs to be programmed to measure and download data at a certain time and form. The storage module is the device used to transport the data and programs between the field site and the office or transferring the data directly to a laptop. Furthermore, it also increases the data logger's storage capacity by storing data and programs in a solid state module or a memory card. The thermistor chain itself consists of the thermistor sensors which are placed with the desired space between them and wrapped up in a plastic coating.



The drilling

This part of the fieldwork is not to be underestimated, especially not if the drilling takes place in loose material or boulders. It is heavy work and do involve quit a lot of practice. If one has to do the drilling one-self several things have to be taken into consideration.

The type of drill needed is dependent on how deep the bore holes will be, the diameter of the hole and the material within the drilling takes place. The drilling requires electricity and water supply which can turn out to be a problem in remote areas. It is possible to drill dry but it is much to prefer drilling with water. This will cool the drilling head during the drilling, smoothen the drilling and is a good deal faster than dry-drilling.

For the design of the bore hole system, the first step is to decide the diameter of the bore hole. To reduce air circulation within the bore hole choose the diameter of the drilling tubes as small as possible. Otherwise the air circulation within the bore hole, once established, can disturb the natural temperature profile. The chain should be fastened to a weight at the end to be sure that there is weight enough to keep the chain straight and get it all the way to the bottom. This weight can have a larger diameter than the actually chain which is to keep in mind when deciding the diameter. Consider as well the option of wrapping neoprene tightly to one side of the chain. When the chain is lowered in the afterwards the sensors will be pressed against the wall of the bore hole. This will result in a more precise measurement of the material and also prevent air circulation in the hole.

Next step is to decide the length of the bore tubes. It is a good idea to divide the full length of the bore hole, and thereby the tube length, into a certain number of meters. Or said in another way: if the hole has to be 6m deep use 6 * 1m. tubes plus one 1/2m. tube. This is due to practical reasons during the drilling.

Third step is to decide for the drilling crowns. It is necessary to know the geology of the material where the drilling will take place. In loose or coarse material several different crowns that can be changed according to varying material during the drill are needed. This often implies at least one crown for loose material and one that fit the main hardness of the boulders. Let the company guide you according to the material, how deep the bore holes will be and how many holes needs to be drilled.

A final very important consideration is wherever the bore hole should be installed with an inner tube. An inner tube is a thin plastic tube which is installed during the drilling. The advantage of installing an inner tube is that a lot of problems will be avoided during the actual drilling as it prevent the hole from collapsing every time the tubes are pulled out of the hole to be emptied. The disadvantage is that it will also act as a thin barrier between the thermistor sensors and the material which temperature is to measure.[continued]

http://www.unis.no/RESEARCH/GEOLOGY/Geo_research/Ole/PeriglacialHandbook/ActiveLayerTemperatureMonitoringBlockyMaterial.htm

It seems to me that these concerns are addressed.

 

[Bystander]

Originally posted by Ivan Seeking
Dunno.

Compare carbon dioxide concentrations at latitudes of northern hemisphere industrial and population centers to carbon dioxide concentrations at higher latitudes.

http://www.unis.no/RESEARCH/GEOLOGY/Geo_research/Ole/PeriglacialHandbook/ActiveLayerTemperatureMonitoringBlockyMaterial.htm

It seems to me that these concerns are addressed.

Ivan, I don't review borehole papers for a living --- the two or three I've run into involve universities taking over donated holes and adapting them for temperature profiling. The adaptations do not include pulling casings; they do not include convection controls. Your reference points out the other grim problem --- thermistor stability.

 

[Nereid]

Haelfix,

Also be careful to distinguish between work done to model the past with extrapolations - based on those models - into the future. By necessity the extrapolations include links to things like industrial activity, population, etc. Several professional economists have questioned the soundness of the (physical) scientists' (economic) assumptions and (implicit) economic models.

On a separate, but somewhat related matter, many of the ideas for mitigation are ill-conceived, economically; and the 'cost' of reaching certain (environmental) goals or targets may well be much smaller if proposed programs were designed with a better understanding of economics.

 

[member 5645]

And I was chastized for simply saying that global warming is definite [zz)]

 

[Nereid]

Originally posted by phatmonky
And I was chastized for simply saying that global warming is definite [zz)]

I must be in the slow class today ... there has been a rise in average global temperature - no one surely is contesting that! What's much more difficult is to understand the factors which are contributing to this clear signal, and to have confidence in models of what will happen in the next 50-100 years.

For example, homo sap, directly or indirectly, has contributed to x% of the global warming over the past t years. If t ~<100 years, x ~>50%; if t ~10,000 years, x ~> ??

And even when we do have confidence in the models, or recognise that it would be prudent to reduce global homo sap induced rises in atmospheric CO₂ to y gigatonnes pa, how do we go about attaining that objective?