Explain the greenhouse effect me. Is it real? The author of the below link seems to think it some sort of liberal conspiracy.
http://www.frontpagemag.com/Articles/ReadArticle.asp?ID=7746
Explain the greenhouse effect me. Is it real? The author of the below link seems to think it some sort of liberal conspiracy.
http://www.frontpagemag.com/Articles/ReadArticle.asp?ID=7746
We’ve had several threads about this over the past couple of years. Here are a few you should check out:
http://boards.straightdope.com/sdmb/showthread.php?threadid=104877
http://boards.straightdope.com/sdmb/showthread.php?threadid=134552
http://boards.straightdope.com/sdmb/showthread.php?threadid=136373
The best links available on the web to the current state of the science are the IPCC (International Panel on Climate Change) website and the report issued a couple of years ago by the National Academy of Sciences.
The short answer is that it is very real and if you looked in reputable refereed scientific journals like Science or Nature, you would find that the reality of this threat is now taken as fact in the scientific community as a whole (which doesn’t mean complete unanimity among scientists, just like you can find PhD biologists who don’t believe in evolution). If it is a “liberal conspiracy”, it is certainly a very successful one, having won over the peer-reviewed scientific community among others. A recent editorial (January 17, 2003) in Science by Editor-in-Chief Donald Kennedy stated:
This is not to say that there are no uncertainties…There are many. The estimated range of the warming that might occur due to humans in the next century, as given by the IPCC (International Panel on Climate Change), is pretty large: 2.5 to 10 degrees F. Note, however, that the uncertainties run in both directions…i.e., it could be less bad than we expect or it could be worse. One of the hypotheses that has been gaining credibility in the last few years, although it is still pretty young, is the idea that the anthropogenic (human-caused) forcing of the climate could lead to a very sudden non-linear and dramatic shift in climate. One way this could happen, for example, is if the forcing caused the Gulf Stream to shut down (and there are various scenarios for believing that it might).
As for explanation of the effect: The basic idea is that certain gases like CO2 and methane when added to the atmosphere act like a blanket, causing the energy from the sun that is re-radiated by the earth to be trapped. Of course, this heat-trapping is necessary for life on earth as we know it. The problem is that the burning of fossil fuels, as well as land use changes, are upsetting the balance by causing more and more of these gases to be emitted in the atmosphere. As a result, the levels of CO2 are now something like 30% higher than the pre-industrial baseline of ~150 years ago. This results in a human-induced “forcing” to the global climate system.
Although CO2 is constantly exchanging between atmosphere, oceans, and land, the process is slow enough that, even if we stopped burning fossil fuels tomorrow, the level of CO2 would not drop back down to levels near the baseline for on the order of one hundred or even a few hundred years. (I am slightly sketchy on the timescale.)
Major Kong: By the way, I wrote the above-reply before I even looked at the piece you linked to. I’ll give you a few comments on that piece:
(1) The paper that is referred to is one of hundreds, if not thousands, of papers being published on the subject of climate change every year. It is published in a multi-disciplinary journal called “Energy and Environment” which is, near as I can tell, a real scientific journal but I don’t think it is a very high-status one in the scientific community, like Science, Nature, or the major more-specialized journals in the climate field. It is written by some of the small group of scientists well-known to have strongly-held views about global warming that do not jibe with the rest of the scientific community as expressed in the peer-reviewed literature (Baliunas and the Idso clan being the 3 of the 5 authors who I am familiar with in this regard). If one doesn’t believe in global warming, one can always choose one paper out of thousands published in the peer-reviewed literature (and in a lesser journal) and elevate it to a status above all the others; however, if you are a reputable scientific organization like the IPCC or NAS, you actually have to consider the full range of views expressed in that literature. [I also don’t even know how well the writer has represented this particular scientific paper although, given the authors on the paper, I am willing to believe he has not distorted its conclusions too blatantly.]
(2) The rest of this piece is full of half-truths and distortions. For example, while it is true that some pollutants (like sulfur) can actually contribute a bit of a cooling effect, it is just silly to imply that the solution is to throw more sulfur into the atmosphere. There are other environmental problems associated with sulfur, besides which we probably don’t understand the climate system well-enough to play these games of trying to play one type of emissions off of another (besides which, I believe sulfur emissions remain somewhat more localized so it may be impossible to “balance” the effects even if we tried…the forcings will come in in different ways). He also misrepresents Hansen’s views since Hansen does not believe CO2 is not the most important factor but was rather noting the possibility that it might be easier, and possible to get more bang-for-the-buck in the short term, to reduce some of the other greenhouse gas emissions; but, he didn’t doubt that we have to deal with CO2 too. [Also, I am quite sure that the accounting in Kyoto includes many of these other greenhouse gases, so this is not an argument against Kyoto.] Finally, he makes the common mistake of confusing the prediction of climate to the prediction of weather (and, I think he also blatantly misrepresents the way in which the Weather Services “scores” the accuracy of its forecasts at any rate).
In short, this is the typical garbage that you can find all over The Web which misrepresents the state of the climate science for political purposes while arguing that “the other side” is the one misrepresenting it for political purposes. The problem with this point-of-view is that “the other side” doesn’t just include Greenpeace and Sierra Club and scientists sympathetic to the environmental cause. It includes nearly all of the scientific community that is up on the state of the peer-reviewed research in this area! A large conspiracy indeed!!!
Thank you for the very detailed answers.
No problem. As a scientist (although not a climate scientist) interested in issues at the intersection of science and public policy, this is one issue that I follow quite closely.
From the article:
Do you know what petition the author is refering to? Is the the same one discussed in the other thread?
Meaning this petition:
Here’s the petition.
Sign it yourself, and make it “more than 17,001”. Choose your academic degree honestly. I’m sure everyone else has.
Here’s a state by state listing of all the signers. Perhaps you can recognize someone from your state. I didn’t.
The climate doesn’t exactly stay the same or else there wouldn’t have been ice ages.
Since well documented meterological data from previous times isn’t available, it remains to be seen whether a shift in climate is a) exclusively man made and b) catastrophic. After all, if there is a manmade counter against the next ice age, that wouldn’t be such a bad thing.
Nevertheless, the reduction of emissions is a worthwhile effort and that trend should definitely continue (just in case I am wrong about the green house effect being the big boogey man).
It could be the result of Milankovitch cycles, but this is not the sort of thing that you leave to chance. The possibilty that this is the result of man-made emmissions is reasonably high and therfore the issue cannot be simply dismissed by pointing to natural cycles.
Well documented meteorological data isn’t necessary, for one simple reason: We’re not talking weather. We’re talking climate. We don’t need to know if in a given year, more than a given amount of rain was falling in the area of today’s Minneapolis. What we need to know is whether the global heat contents increased or decreased, whether there was on a worldwide scale more or less rain, and higher or lower sea levels, and in general higher or lower average temperatures. Such data can be deducted, from sediments, tree rings, ice cores, glacier traces etc.
We can then look at how quickly those proxies changed in the far past, and how quickly they changed in the more recent past. That alone gives us some idea as to how quickly the climate changed in the past, and how quickly it is changing now. The result of one such analysis suggested that what we saw in the 20th century was quicker than anything in the 1000 years before.
As to ice ages, even they do not happen within a few years. Their development can speed up, though, with the collapse of ocean currents such as the gulf stream. That, however, is a potential consequences of any climate change, natural or artificial. If we dropped enough nukes onto the North Pole to melt the ice there, the increased freshwater influx into the sea would threaten the gulf stream as well.
One needs to distinguish two things: The greenhouse effect is a physical phenomenon that is very real, and based on simply physical characteristics. It’s physical background is used in spectroscopy in countless labs all over the world every day. The greenhouse effect contributes to the night side of the earth not cooling off as quickly as it could without the CO2. CO2 DOES absord infrared radiation. There’s not the slightest hint of doubt about that.
The question is whether the increase in CO2 levels since the massive use of fossil fuel is influencing the infrared absorption of the atmosphere in a significant fashion, and if that increase has an effect on the climate.
Those are two very different issues. One is a physical fact that’s based on the quantum physical aspects of the carbon-oxygene bond. The other is a climatological model based on what we know about climate today.
Atmospheric CO2 has increased by 30% since the start of the industrial revolution just 300 years ago, and levels have not been this high for many thousands of years.
Even if this is an incredibly unlikely coincidence, we should surely not continue to push any variable so far off equilibrium in systems as delicate and intractable as global climates?
Yeah, it is indeed the infamous “Oregon Petition” that we discussed previously and you already found a nice link that describes how it worked.
I should also note that, even among those folks who challenge the scientific consensus on global warming (at least among those who enjoy at least a marginal amount of respectability as scientists), there is as far as I know no debate about whether we are responsible for this rise in CO2. The contrarians like Patrick Michaels and Richard Lindzen rather tend to argue something like:
(1) Lindzen: The sensitivity of the climate system to CO2 is less than nearly everyone else thinks because there are negative feedback effects due to clouds (and the positive feedbacks that others have identified are somehow wrong or unimportant).
(2) Michaels: The sensitivity of the climate system to CO2 is toward the low end of the range that the IPCC concludes and, furthermore, the effects will not be global but will be concentrated in the very lower part of the troposphere in cold dry regions where there are not a lot of people anyway.
I am not sure if Michaels, who has been a contrarian on this topic for many years now, has always been carving out this “niche” or whether he used to make broader claims against the scientific consensus…But that is where he is today (or, more precisely, when I heard him speak ~2 years ago).
Here’s a link to the NAS report about the IPCC report:
http://books.nap.edu/html/climatechange/
Here’s a link to the IPCC report:
http://www.ipcc.ch/
Here’s a link to the state dept summary of th eNAS report:
http://usinfo.state.gov/topical/global/environ/01060602.htm
Hope these help, Major Kong.
It is possible that carbon dioxide levels in the Mesozoic were 5x the present level;
it is also possible that the main factor preventing the return of glaciation is anthropogenic carbon dioxide;
it is also possible that if anthropogenic global warming continues there will be a catastrophic release of methane from methane hydrate deposits in the seas and oceans, causing a rise in temperature to Mesozoic levels.
So it is undoubtedly the best strategy to cut down on CO[sup]2[/sup] emissions and concentrate on solar and tidal/wind power in thic century… assuming that fusion power is not available.
Iwould point out, however, that the world was not uninhabitable in Mesozoic times, far from it-
It would take a lot af adjustment by the peoples of the earth to live in a hot moist greenhouse earth, but with luck it could be done.
jshore or anybody else,
Can you comment of the idea that cities and other urban areas are creating “heat islands” and are causing the global mean temperature to appear higher. And that we should only use satalite data.
Here is a link to some research in this area.
I can’t find where the author is suggesting we add sulfur to the atmosphere.
Major Kong: One can grow old trying to look into and debunk all the claims made by those who claim that global warming is not occurring. That is why it is important to have refereed scientific journals and then, for scientific issues witn important public policy implications, occasional assessments of the current state of the knowledge in the refereed literature, such as those conducted by the IPCC and the NAS.
But to try to answer your question to the extent that I know the answer: Of course, urban heat island effects can cause local temperature increases. This is such an obvious problem that it bends credulity to believe that this hasn’t been considered and reconsidered in the literature. Of course, Daly, not being constrained by the rigors of peer-review, is free to show data selectively to make it look like it is likely that if the urban heat island effect is removed from the data, the warming is no longer apparent. However, this is completely at odds with the view in the scientific literature. [By the way, I think most of the contrarians, unlike Daly, pretty much accept the reality of the surface observations as showing warming over the past century even if they do not agree with the attribution to human sources or, like Michaels, claim that it is due primarily to warming in cold dry places.]
Also, the whole satellite thing turns out to be rather confusing. It is great to say, “We have this cool modern way of measuring the temperatures that is far better than the silly old-fashioned way.” However, the fact is that those satellites were not designed for this purpose in mind and their data is not so wonderful. When it was first published, it actually showed a cooling trend in the part of the troposphere it is sensitive to. However, it was later realized that the data had to be corrected for the decay in the orbit of the satellites and once this was done, the cooling trend became a warming trend, albeit still a smaller one than is observed in the surface observations. The remaining discrepancy is not all that large compared to the uncertainties in the measurements but does remain somewhat of a puzzle and there was a whole NAS report released on this, and mention of the issue in the more recent NAS report that I linked to. I heard there was a recent Science article claiming to resolve it more…But, I haven’t seen it myself.
Thanks again jshore.