To be picky, (1) you brought up the issue by referencing this trend as a reason why we do not need to get excited by poor GISS methodologies and data quality.

To be picky, I brought up northward movement of hardiness zones (related to lowest mean temperature), not length of growing season (timing of freeze events). And as I have told you before, I brought the matter up in response to Frank K.’s patently wrong assertion

We are being asked here in the US to believe that we must engage in a destructive cap and trade policy, largely on the basis of temperature histories generated by codes like GISTEMP.

If you really want to read up, don’t just stop on page 1 of the search results I linked to.

Concerning droughts: no, I do not believe that they have any meaningful impact on produce prices. First, Australia has had worse droughts in the past, and I am confident that they will have similar droughts in the future. Second, globally, wheat and grain production is up. Third, produce – vegetables and fruit – is more typically irrigated as opposed to grains. Economic development and increased incomes in many places around the world have influenced meat & dairy consumption, but impact on produce is not obvious. If there really were definitive widespread trends toward healthier eating, then I would give substantial credit to that, but such trends tend to be very localized or restricted. I tended to put a lot of blame on energy prices until I found out how little it cost to transport produce. So that is why I remain curious on the impact of the growing season on produce prices.

An increase in the growing season has a tremendous favorable impact on productivity. We would love to plant 120-day corn but we dare not. But we have gone from 93-day corn to 101-day corn, and our productivity has gone up over 100%. (If I told you how much over 100%, you may not believe me.) To be sure, some increased productivity is due to increased CO2 concentrations – at least 16% according to my reckoning. Better genetics and increased growing season account for the rest, and I can’t give you a good separation of the two.

Quoting you: “You brought up the issue of growing seasons, claiming there were no studies . . .” To be picky, (1) you brought up the issue by referencing this trend as a reason why we do not need to get excited by poor GISS methodologies and data quality. (2) I did not claim that there were no studies; rather I claimed that I had not seen any studies and that GW Pessimists had not been able to show me any. If I properly define my question, I think that my request remains unanswered. I did look at eight of the studies that you linked to (not just the three you cited). I forget how many, but a lot of them did end around 1998, as I stated in my last post, and they all started in decades when we know GMT was low. Looks like mighty fine cherry picking! And to be relevant, the studies should include the last 11 or 12 years. I do wonder about using linear regression in a phenomenon that is characterized by oscillations and perturbations.

I do think that we could agree on a few things. (1) Growing season length has increased since the cold decades in the middle of the last century. (2) We are not sure that the growing season has increased in comparison to the 1930s. (3) We would not be surprised if the growing season has lengthened as the world emerges from the LIA. And maybe I could venture a fourth: The science is not settled.

The widespread dip in temperatures in mid-20th century is wide recognized. It is child’s play to show a positive trend from then to the El Nino-affected 1998. Most of the studies cited used a starting point in mid-century or post-1970s and ended around 1998.

I only cited three papers, two of which do not even include 1998 in their data; all of them determine their results from linear regression covering at least 4 decades worth of data, so the impact of 1998 is minimal at best and will certainly not determine the trend. Sorry, this is a non-issue.

You brought up the issue of growing seasons, claiming there were no studies; I simply looked for what seemed to me to be the most obvious search terms and browsed the results. If you look at the data, you will notice that the dates typically vary by 10 to 30 days from year to year, so the record is very noisy; it is my impression from this minute collection of papers, that it is even more noisy than the temperature record. You’ll have difficulty to compare single decades like the 1930s and the post 1998 decade in a meaningful way because of this noise. If you further restrict yourself to a single region, you’ll have local climate, but nothing about global climate.

I do wish that researchers have understanding of the physical world, instead of just doing computer gymnastics. The effective growing season does not start with April’s last killing frost, but rather when farmers can get out into the field.

Your concern is absolutely valid and important from the farming point of view. Frost alone is an invalid metric for that. I also agree, that a longer growing season is beneficial, provided the other climate parameters like e.g. amount and timing of precipitation remain the same; the concern of climate change is that they may change to the worse. The studies I linked to seem to be more interested in whether a change in climate is detectable in the data or not, rather than being useful to give farmers hands-on advice. Hence sometimes rather artificial definition(s) of growing season are used, with the sole concern, that these definitions can be calculated for preferably long stretches of the climate record. So they use frost data or data of leaf growth and so on, they use what they have at hand.

So much for the growing season from the point of view of climate change detection, now allow me to showcase an area where I am simply uninformed. How would an increase of effective growing season (in the sense you used it) by, say, 10 days increase the productivity? It is not obvious to me, as that period does not seem to be long enough to allow for an additional harvest per year. Would it simply diminish losses and increase crop security?

As a side note, I would be interested in seeing whether trends in growing seasons since 2000 has played a role in extraordinary growth in produce prices which have grown substantially above the overall CPI.

Don’t you think, droughts would have a bigger effect? They cut e.g. Australia’s wheat production in half in 2006 and 2007. Another strong effect is the increased demand for dairy products and meat in countries like India and China.

I apologize that I did not clarify the time period of growing season trends that interests me. The widespread dip in temperatures in mid-20th century is wide recognized. It is child’s play to show a positive trend from then to the El Nino-affected 1998. Most of the studies cited used a starting point in mid-century or post-1970s and ended around 1998. My own records confirm a lengthening growing season in that time frame. I am more interested in comparing today’s length to the 1930s and what has happened since 1998.

Even the studies you generated had words like “conflicting evidence” and “trends in fall freezes are not consistent” and “Our results do not correspond well with . . . with fluctuations in hemispheric mean temperature.”

I know that both sides are guilty of just hearing the talking points, but it seems that Global Warming Pessimists have a profound weakness to not dig deep and understand what is really going on. For example, One study that did not start mid-century was the Illinois case that you cited. Here is a very relevant passage to understand: “lower portion of the October probability distribution shows modest cooling in Tmin (–0.2 ° C/100yrs for the 10th percentile), while middle and upper portions of the distribution show very large rates of cooling (up to –1.5 ° C/100 yrs for the 40th–70th percentiles).” In essence, they found that the end of the growing season was not getting later – although the last killing frost in April was getting earlier. (Now start the rant.) I do wish that researchers have understanding of the physical world, instead of just doing computer gymnastics. The effective growing season does not start with April’s last killing frost, but rather when farmers can get out into the field. How much can we plant when a foot of snow stands on the field – even though the last killing frost is gone? Though the last killing frost was long gone, how much planting was done during the spring floods along the Red River? The key to the length of the effective growing season is not April, but rather how soon the killing frost comes in the fall. Often researchers sound as ignorant and ridiculous as Obama did when he blamed global warming for the Red River floods. The causes of Red River flooding were just the opposite: (1) cold winter temperatures caused a hard freeze in the ground which cannot absorb as much melted snow; (2) cold temperatures meant that ice up north did not melt in a timely fashion which causes back-ups and floods; and (3) cold early spring temperatures led to blizzards instead of rain.

Again, I have not yet seen studies that show that effective growing seasons are now longer than in the 1930s when farmers farmed the bottom of dried-up lakes. Given the wide-spread warming since LIA’s end, I fully anticipate that the growing season has lengthened, but so far studies so far seem to find that this is true from mid-century to the late 1990’s — and that has been a fortunate boon to feeding the world’s population. As a side note, I would be interested in seeing whether trends in growing seasons since 2000 has played a role in extraordinary growth in produce prices which have grown substantially above the overall CPI.

The fact is that the climate has been warming naturally, in fits and starts, since the LIA [and from the last great Ice Age before that]. The warming trend line over the past couple of hundred years hasn’t varied much at all

and garnished it with Akasufo’s plot. All I did was take him by his words. And as I noted, it’s obviously not the right thing to do

@Smokey
Since when do you call on authority and go ad hominem, Smokey?

I have taken the time to look a bit at the figure by the much acclaimed Prof Akasofu “who has forgotten more about climatology than” I “ever will”.

Straight from Prof Akasofu’s PDF, linked by Anthony, the GISTEMP data he used in figs. 1a and 1b is from Hansen et al 1999, no idea why Akasufo could not be bothered to include the last ten years of data. Be that as it may, the caption of his fig. 2a claims “The red line is a smoothed version of the 5-year mean in Figures 1a and Figure 1b.”. I have superimposed fig4 of Hansen and fig2a of Akasofu and matched the scales by linearly stretching Akasofus plot by appropriate ammounts.

Now take a look: http://i44.tinypic.com/33pf41z.png

Would you please explain to me, which smoothing algorithm will result in the observable time shifts of the peaks (1900, 1940) into the future by about 2 to 5 years and the gross mismatch in the period 1905 to 1935, where Akasufo’s “smooth” is way too low, just as in the period 1980 to 1990? Would you please explain to me, why the 0°C mark on Akasofu’s plot is not in the middle between his plus and minus 5°C marks? Would you please explain to me, how he retains the full width of the time range, i.e. how does he interpolate the ends? How about a little audit of the graphic you base your argument on?

Free hint: Akasufo can not have used a running mean.

Oh, BTW, I don’t report to Realclimate.

Smokey, you spin a nice fairy tale of what is happening. You are telling me that nothing has changed in the 20th century with regard to previous centuries, the warming trend is just the warming trend from the last ice age. Let us for the moment forget about Prof. Akasofu…

No, let’s not forget about the good professor, who has forgotten more climatology than you and your cronies at realclimate will ever know. That chart is not mine, as I made clear. Prof Akasofu put it together, and since he knows immensely more about the climate than you do, I accept his informed analysis as being much more accurate than anything you can possibly come up with.

I’ve re-read my post @16:39:30 very carefully. Having read it again, I stand by it. Every word. And you could learn something yourself by memorizing the second paragraph.

Now run along. Realclimate is waiting for your breathless report.

“It is possible but far from certain that the ancients did build a canal from the Mediterrean to the Red Sea.”

It is thought there was more than likely a canal built by the ancient Egyptians but it was not one that was consistently open all the way through

http://www.reshafim.org.il/ad/egypt/timelines/topics/canals.htm

Tonyb

@Smokey (16:39:30) :
Smokey, you spin a nice fairy tale of what is happening. [Prof. Akasofu's graph] implies a linear warming from the last ice age at a rate of more than 0.5°C/century (eyeballed from his plot) plus superimposed “cycles”. You told me, that the last century is just the same as previous ones. So let us project back to Roman times, 2000 years ago. Are you seriously contending, that the global mean temperature was 10°C colder in Roman times?”

The graph implies nothing of the kind. It shows a linear trend line of about 0.5 C as a “recovery from the Little Ice Age.” The Little Ice Age occurred circa 1700-1800, about a millenia and a half after the Roman era. Extending the trend line to be representative of temperatures prior to the Little Ice Age is silly, as doing so implies that the Little Ice Age had no effect on the trend line, which is exactly the opposite of what is posited by the graph.

Hansen has been PAID by the government to do ONLY this since 1988:

Oh, I see. So he is not the director of the Goddard Institute for Space Studies. He is not running and improving GISS modelE. He is not writing articles for the peer-reviewed literature. ALL he is being paid for is maintaining the GISTEMP code and improving his coding skills, because you say so. You almost fooled me. Almost.

If you are to come up with the number of rice corns inside a sack, you can either weigh the contents and divide by the average weight of the rice corn deduced from a small sample, or you can count the individual rice corns, checking each under the microscope whether it is broken or not and for how much of a rice corn it does count. Nothing wrong with the latter approach, but the first one will give you good enough accuracy for most practical purposes and works a lot faster, taking up way less resources. It’s an admittedly crude analogy, but to me it looks like Hansen is using the first approach, while you and others are advocating to use the second.

Your understanding of peer-review is equally flawed: It is not the last line of defense, it is simply the first hurdle in scientific fact finding. Keep in mind, that Schön and Hwang were ousted by the scientific community, not some internet blog.

The point is this: neither Hwang nor Schön would have lasted a week on this site or others like it before their fraud was uncovered

You are kidding me, right? You must be. Remember Dr. Roy Spencer posting his piece on the interannual and trend signal of C13/C12 isotope ratio? The one with the (unfounded) bottom line:“If the C13/C12 relationship during NATURAL inter-annual variability is the same as that found for the trends, how can people claim that the trend signal is MANMADE??” ? Where was the critical thinking of the readers back then? Tamino pointed out that the equality of the slopes was a mathematical necessity. That was not good enough for WUWT. I showed, that you get the same result, if you substitute Dow Jones index and gold price on different timescales. Not good enough for WUWT. I posted a detailed mathematical proof here on WUWT. It was pretty much ignored. I do not claim fraud, but gross error. Don’t you think, there should have been at a minimum a heads-up attached to Dr. Roy Spencer’s article, if not a retraction? Nothing of that sort has happened. So don’t you dare give me your “would have lasted a week on this site”, it’s simply laughable.

Certainly, the robustness of representations of US and global temperature trends can (and should be) questioned. imo the case is not closed.

I can’t believe (and even those doing the work don’t admit) that for example EVERY site that was moved from a city to an airport immediately began recording cooler temperatures

Maybe not. But even if one stipulates that they did, there is no question that from that point onward, airports (on average) have warmed much faster than “good” stations, in fact much faster than the average of all stations, for a number of reasons. So, where’s the adjustment for that, then? Even if the initial adjustment is correct, there is no account made for conditions afterward.

Perhaps the adjustments are good for some sites, but I haven’t been convinced that blanket corrections are appropriate. I can’t believe (and even those doing the work don’t admit) that for example EVERY site that was moved from a city to an airport immediately began recording cooler temperatures (see http://cdiac.ornl.gov/epubs/ndp/ushcn/ndp019.html )

I won’t like an adjusted curve until the “correction” for EACH site is supported by some sort of data (quantitative info is best, but qualitative would at least provide some support).

“Correcting” each site in this manner would be a humongous undertaking. Until that time it is done, (and after as well), I would suggest those in charge of the official trends provide at least two versions of their trends (raw and adjusted), and maybe even a third ….. evidence based adjusted (of course, where the evidence is laid out for everyone to see).

“You’ll find a lot of quick and dirty programming in research. I think, very few researchers have an education in programming practices. You pick up what you need during your studies and work from there. So you have an idea of what you want to do and write a Q&D program.”

—

Hansen has been PAID by the government to do ONLY this since 1988:

You’re telling me that he can do no better than “quick and dirty” unintelligent, badly-written, hacked, uncommentedn GISS code for twenty years, but that we MUST spend 1.3 trillion dollars immediately – with not even two days to debate the bill – based on that “quick and dirty” unaudited and undocumented code?