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If It's That Warm, How Come It's So Darned Cold?
(The following is an excerpt of the overview section of a paper by James Hansen, Reto Ruedy, Makiko Sato, and Ken Lo. The full paper can be read here.)
Public skepticism about global warming was reinforced by the extreme cold of December 2009 in the contiguous 48 United States and in much of Eurasia. The summer of 2009 was also unusually cool in the United States. But when a cold spell hits, we need to ask:
- Cold compared to what. Our memory of the past few winters? Winters of our childhood? Winters earlier in the 20th century?
- Cold where and for how long? Regional cold snaps are expected even with large global warming. Weather fluctuations can be 10, 20 or 30 degrees, much larger than average global warming.
- The reality of seasons. As the plot of Earth we live on turns away from the sun, in
winter or at night, it cools off. That’s true even with global warming, albeit not quite so much.
Before addressing these matters, we note that scientists reporting global warming have come under attack for a supposed conspiracy to manufacture evidence of global warming. Perhaps because some members of the public accept these charges as reality, vicious personal messages are sent to the principal scientists almost daily.
The spiral into an almost surrealistic situation with ad hominem attacks on scientists may have originated in part with vested interests who do not want society to address climate change. But there is more than that – including honest, wishful thinking that climate change is not really happening. But wishing does not alter facts.
The scientific method practically defines integrity.
[Albert Einstein: “The right to search for truth implies also a duty; one must not conceal any part of what one has recognized to be true.”
Richard Feynman: “The first principle is that you must not fool yourself – and you are the easiest person to fool.”
All scientists make honest mistakes, but the scientific method is designed to correct them. The skeptical nature of the scientific method causes conclusions to be reexamined as new data appears. Cases of deliberate fudging of data, of scientific fraud, are so rare that these infrequent episodes live in infamy for decades and even centuries.
We know of no cases of fraud in analyses of global temperature measurements. Despite unfounded accusations, we believe that our best approach is simply to continue to report our scientific results as clearly as possible. Most of the public continue to respect scientists for what they do and how they do it. We presume that most of the public can separate science from political commentary.
Our data show that 2009 was tied for the second warmest year in the 130 years of near‐global instrumental measurements – and the Southern Hemisphere had its warmest year in that entire period. Before discussing these data, and their reconciliation with regional cold anomalies, we must consider the time frame of comparison.
If we look back a century, we find cold anomalies that dwarf current ones. The photo reproduced above shows people walking on Niagara Falls in 1911. Such an extreme cold snap is unimaginable today. About a decade earlier, in February 1899, temperature fell to ‐2°F in Tallahassee, Florida, ‐9°F in Atlanta, Georgia ‐30°F in Erasmus, Tennessee, ‐47°F in Camp Clark, Nebraska, and ‐61°F in Fort Logan, Montana.The Mississippi River froze all the way to New Orleans, discharging ice into the Gulf of Mexico.
As we will show, climate is changing, especially during the past 30 years. The changes are perceptible, even though average temperature change is smaller than weather fluctuations. The answer to the simple question: “How come it’s so damned cold” turns out to be simple: “Because it’s winter."
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© InsideClimate News |
One additional thought
After my longer post below an additional related questions came to mind. The quote from the blogger frogbandit is meant to explain that global warming is a global trend and that individuals experiencing a cold snap or a warm snap cannot say from that that the globe is respectfully cooling or warming. That is a good point well taken.
But again, when you summarize and mentioned that a perceptive person should notice decadal global warming trends aren't you violating that principle? A person living in the same area for 10 years would be a single temperature detecting instrument. Part of the essay's point is that temperatures in one location tell you nothing about the "global component" of global warming. You said nothing about such a person traveling around the globe taking perceptive readings. The point obviously is that you should remove the references to what any individual person would or should perceive because it undercuts the global trend substance of the essay.
Retracting "Nice Try"
By the way - when I posted and saw my "Nice Try" subject line - that should be retracted. I'm asking for a rational discussion and that does not help so my apologies.
Best regards,
Tom
Nice Try
Thank you for the comment and the chance to engage on this. No I am not really that ignorant. Nice attack. Maybe "anonymous" is Dr. Hansen commenting on his own blog but I would hope for serious discussion instead of attack. The feedback can perhaps help improve the essay.
By the way, I am a lay person global warming skeptic (and engineer) but found this article hoping to learn about the latest evidence to support global warming and learn more about the best evidence that is available. You may not believe this, but I am looking for a rational discussion here and have some serious questions and suggestions for improving the article to be more clear.
So to the anonymous comment. You make it sound like I quote two different sections and thus there is no real relationship between the two. Here's more context from the quote I cited above:
"Although the THREE INPUT DATA STREAMS that we use are publicly available from the organizations that produce them, we began preserving the complete input data sets each month in April 2008. These data SETS, which cover the full period of our analysis, 1880-present, are available to parties interested in performing their own analysis or checking our analysis." (emphasis added)
The point of my question is that the impression that is left to the reader is that these three sets all cover the entire period starting in 1880. Obviously there was no satellite data prior to 1978. As a lay person in the study of climate change, when I read the essay, it should be clearer with respect to the underlying data. For example, taking Anonymous' comment to mind, if getting the "big picture" requires multiple sources of data, then the big picture prior to '78 is not nearly as clear as after '78 since you do not have all of the data streams.
So reading the essay and then finding out that the satellite data wasn't available until 1978, I noticed that FIG. 2a and b both dramatically increase around 1978. Does the addition of satellite data have anything to do with that? How does that new satellite data stream effect the overall analysis? Also, it would be great to know at least briefly how the confidence in the data grew over time. I doubt there were several thousand meteorological stations in 1880 or antarctic research station measurements then. I may be wrong but I think it would be very helpful to add a paragraph simply explaining when these data streams came partially or fully on-line and why the data prior to that should be trusted. Such information would help the public to have the appropriate amount of confidence in the analysis. For me, after doing just a little of my own research, it seems to bring up some serious questions.
Another question I have as well. The authors note on page 1 that "the [climate] changes are perceptible, even though average temperate change is smaller than weather fluctuations." In the Summary the authors also state that "However, the perceptive person should be able to notice that climate is warming on decadal time scales." I have tried to think in my own life (40 yrs) of whether I can be so perceptive. I am assuming Dr. Hansen is such a person. I cannot think of any specific personal experience that tells me that I have actually perceived global warming on a decadal time scale. Summer is generally hot and winter is generally cold.
So as a question for Dr. Hansen on these comments in the essay. Do you have any personal "perceptions" that tell you the climate is warming? If so, what are those? It seems that in an essay such as this, statements like the ones quoted above are not useful in the context of an essay on climate data and trends. Unless there is data to back those up (worldwide surveys I guess??) I would suggest leaving these out - especially of the Summary.
Best regards.
Tom
Satellite Data
In your essay you discuss the three sources of data: (1) several thousand meteorological stations; (2) satellite observations and (3) antarctic research station measurements. You note that you've been preserving the three input data streams since April 2008. Then you say "These data sets, which cover the full period of our analysis, 1880-present, are available to parties in performing their own analysis or checking our analysis."
Dr. Hansen - Please explain how you obtained your satellite data from 1880 - 1978.
Thanks.
Tom
Are you really that ignorant?
Are you really that ignorant? You did read the group's full essay to pull out the two different sections that you quoted, so I'm guessing you're not -- but that you believe the public is.
So for everyone else, the essay does NOT say satellite date came from before 1978. The commenter knows that and is trying to mislead you. Why? You'll have to answer that yourself. As for the use of multiple sources of data, anyone who ever took a history class knows that getting the big picture typically requires multiple sources.
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