NASA GISS: adjustments galore, rewriting U.S. climate history

@gcapologist (18:07:37) :
I’ve done research in physics myself, feel free to accuse me of “arrogant self confidence”, too.
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.

bluegrue (01:19:18) :

@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.

Bluegrue:
First, an apology, and then a rant.
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.

Bluegrue
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.