But not the point I’m dealing with now. I prefer to have problems with English rather than avoiding what is the latest item here, maybe it is a nitpick, but I had many, many lukewarmers that unintentionally (it seems) give people a partial view of an item to make it look misleading (again, hopefully unintentionally, but we’ll see depending on the nest answer.)
The question, in other words, that you are avoiding is: You **do **realize that **just **showing a record that goes back for a few decades gives a misleading impression? When it is not explained that the slope up (and the record year after year) was not there at the beginning of the industrial age?
Of course it may be that this needed clarification may give others the idea that we should get doubts on the assumption that climatologists are mostly doing sociology, not climatology.
The reason I use recent data is that is the only accurate data. The paleo data you reference is incomplete and any conclusions drawn from it little more than speculations. I will say that I have no reason to doubt that C02 content of the atmosphere was approximately 280 ppm at the start of the industrial era. Dr. Nelson uses 288 ppm as the preindustrial baseline. He bases his graphs on the temperature and C02 records since the beginning of the 20th century. I prefer to start my analysis at 1980 which is where the satellite records start. There are also several different temperature indexes to use for comparison.
I would also caution you against you against relying on University press releases. I afraid that the publicists often get the bit in their teeth and there are statements often not in the paper or even contradicted by the paper itself.
But regarding this item of the recent past CO2 concentrations that is also an speculation.
The point here is that one has to be skeptical also of the skeptics, unfortunately, history so far has shown that one has to be more so of the skeptics.
Do you actually read the articles you cite? It doesn’t even suggest that CO2 is a cause and only suggests that glaciation can happen rapidly and doesn’t really suggest a cause. Frankly rapid glaciation isn’t something you want to bring up on the subject of AGW. It is much more likely that CO2 decreases would be caused by glaciation as plant life died.
Frankly your terminology is suggestive. For scientists doubt is a good thing. People only attack doubt when it is part of their religion that is attacked.
If you actually read up on the PETM in Wikipedia, so will see that there are a half dozen hypotheses about happened. This is because of the paucity of hard data about what happened.
I said that adding more doubt than necessary is also unbecoming. Lets remember I’m just complaining of just showing a short snapshot of the CO2 increase and implying to all that the records are mostly natural, in essence I’m saying to others to look at the big picture.
If you hadn’t quoted Dr. Alley out of context people would see that there many sources of uncertainty in the measurements. If you look at the papers he references then you see that they only suggest warming caused by greenhouse gases. This is information we already know because we already measured it in the laboratory. It provides no information at all about the feedbacks from the greenhouse gases which is my central concern.
CO2 doesn’t need to be a cause - it can also be a feedback, in the same way that water vapor is a feedback; warming (cooling) causes CO2 to outgas from the (be absorbed by) oceans which causes more warming (cooling) than otherwise would have occurred (of course, CO2 is currently being absorbed by the oceans despite warming so we know that they aren’t driving atmospheric CO2 levels up).
Also, you keep mentioning the recent climate record as proving that sensitivity is less than assumed, which doesn’t consider many other factors, such as natural climate forcings and aerosols (the latter, if removed, could easily double the observed warming), plus, there is a lag even for short-term climate forcings (adding in long-term changes would double the warming seen). In fact, current climate is being driven by CO2 levels seen about 30 years ago, when CO2 levels were around 340 ppm, 50 less than today and just half of the increase from preindustrial times.
You are perfectly correct. Actually part of the reason I don’t trust paleo records, is that is very hard to identify the order of events precisely and it is really to mix up cause and effect. I would be careful about making statements about how much C02 is being absorbed by the ocean. We know about half of the human emitted C02 doesn’t stay in the atmosphere, but we don’t exactly where the other half goes.
You are getting into a questionable area here. This is physics, not chemistry. There is no scientific basis for assuming a warming lag. The heat is actually generated or not generated. James Hansen wrote a interesting paper in 2005 that suggested that the hidden heat was actually stored in the deep ocean. The subsequent measurements by the Argo buoy system rendered this unlikely, but his underlying point that the heat content of the oceans dwarfs that of the atmosphere has been generally accepted.
You seem to have misinterpreted what I said. I meant that scientists should be doubters, not that you should doubt scientists.
I frankly have a problem with people who use the term ‘skeptic’ to describe people who disagree with the AGW hypotheses. As far as I’m concerned all scientists are skeptics. When you are using skeptic as a swear word, then you are disavowing science.
That problem with relatively high sensitivities is that they sort of work for the last couple of decades but go bad very quickly if you go back to, say 1900.
Also, high sensitivities point to a more unstable climate than the one we have seen and studied.
Finally, one point about aerosols. Whatever the forcings (and the sign) of aerosol, the problem is that they are short lived and therefore do not mix well (unlike CO2). This means that concentrations are much higher in say China that in Peru. if we use aerosols in the average wordl temperature, their effect would have to be of 3 or 4°C to balance their negligible effect in other places.
Well, no, there are skeptics and there are deniers, there are also proponents and there are also alarmists, as it turns out I also have taken against people that do not have support for the extreme alarms they make like Lovelock does.
**Scientific ****Skeptics **though, do take their licks by publishing science, and they do, those who can’t, blog or make websites.
Now, this leaves “lukewarmers” in a spot that Eli Rabbet descrives thus:
I’m sorry. I just realized I didn’t answer part of your question. I am aware of the other forcings. That is why I say that I expect the warming by 2100 to be between 1 and 2 degrees instead of saying that the warming will be around 1.5 degrees. I already addressed the issue that warming can’t sit in the pipeline and not show up for decades.
This is actually a bigger problem for people that think we will have rapid warming caused by greenhouse gases. In their models these other effects are just secondary forcings and feedbacks and greenhouse gasses are the primary forcing.
This post is absurd and another example of of you not understanding basic mathematics. If you assume that c02 would have to double to produce a warming of 1.1 degrees then the total increase in c02 would be for from the 392 ppm to 1880 ppm. The actual IPPC projections for 2100 vary from 583 to a worse case of 983ppm.
If you actually think a 2C temperature will cause the collapse of civilization, then I would like to point out that is roughly equivalent to the climate change experienced by moving from Gainesville to Orlando.
That is very important to clarify as what you are implying is that we will remain in the lower end of the most likely emissions, once again you are assuming we are still at low levers of increases when the already observed increases of CO2 emissions are not telling us that.
Besides, very peculiar “basic” math there, when the CO1 and temperatures what we have been talking about is about a doubling of the CO2 since the industrial age, a doubling of 250 PPM is 560, now where do you get that 583 (low level) number? 535 is the actual (once again low optimistic number) number and so a doubling is indeed withing the projected levels. (Still the very optimistic ones when the most likely estimations in the middle of the pack are higher than that) Also, you are acting like if there are no more years after 2100, the the warming will not stop there as there is a lag on the effects of the CO2 increases.
Add to that that a doubling of 392 is not 1880.
So besides reading the cites, I also do basic math, and it is really your omissions and changes that are getting absurd.
You still don’t understand what you are posting. I was responding to the link that you posted to Rabett Run. Rabett claimed the be refuting the lukewarmer case by using a factor of 1.1 degrees for each doubling of C02 and claiming that it would lead to a temperature increase of 2.5 degrees by 2100 and that would be catastrophic. A C02 level of 250ppm is only relevant if you are talking about the temperature in the year 1800 which was over 200 years ago . If you are talking about a temperature increase from now (2012) to 2100 then you use the C02 level now which is 392ppm. 2.5/1.1 is 2.27 which is the binary logarithm of ~4.8.
4.8 X 392 = 1881ppm.
Yet again you have demonstrated your lack of comprehension and your total innumeracy.
Once again this is telling others just to look at specific sections of the timeline to claim that that only counts and then you fail to tell others about the big picture. There is already an increase of 1 degree when one takes the big picture into account.
And the number you used of 583 was not on the cite you used. A doubling is till not in binary logarithm for many reports on what to expect on the doubling of the CO2 PPM.
If you take the big picture into account, then you are saying that an increase of 1 degree centigrade from the current temperature will have a catastrophic impact on civilization.
Binary logarithms are how the calculations are done. Really. Go ask somebody who know some math.
Not the point. Really, I’m just pointing out that to check the big picture is very important, that and the reports eventually do use regular notation and multiple lines of investigations point at 3 degrees as the most likely outcome of a doubling of CO2.
