Every 10-year trendline in cupholder’s data was increasing.
If you give a statistician the 30-year or 130-year data set with the y-axis label taken off, they will tell you that there is no sign of a levelling-off.
Every 10-year trendline in cupholder’s data was increasing.
A quick clarification: for each of the data links I posted there, the trendline is calculated based on all of the data that’s shown, i.e. for the post-1998 data the trendline is based on the last twelve years, for the post-1970s data the trendline is based on all of the post-1970s data, and so on. In other words, only the data for the last 10 years of data really have a 10-year trendline.
[ETA: Unless you mean you calculated 10-year trendlines for each data set yourself, in which case feel free to disregard this.]
The linear trend is definitely decreasing for this particular plot.
If you give a statistician the 30-year or 130-year data set with the y-axis label taken off, they will tell you that there is no sign of a levelling-off.
I’m seriously skeptical of this.
P.S. Are you saying that the absence of significant cooling is the same thing as the presence of significant warming?
Note that changing the beginning data point to either 1997 or 1999 makes the regression line have a positive slope. It’s not at all surprising that there is enough variability that cherry-picking data is possible. Stuffing a positive outlier at the beginning will, of course, tend to do this.
Note that changing the beginning data point to either 1997 or 1999 makes the regression line have a positive slope.
Agreed. I cherry-picked 1998 as a starting point to counter the claim that the data was increasing “in all cases.”
Still, I would also note that as I explain on my blog post, there is some significance to the observation that global surface temperatures still have not exceeded the 1998 high. (According to the majority of leading temperature measurements.)
In a blind test, the AP gave temperature data to four independent statisticians and asked them to look for trends, without telling them what the numbers represented. The experts found no true temperature declines over time.
“If you look at the data and sort of cherry-pick a micro-trend within a bigger trend, that technique is particularly suspect,” said John Grego, a professor of statistics at the University of South Carolina.
[...]
The AP sent expert statisticians NOAA’s year-to-year ground temperature changes over 130 years and the 30 years of satellite-measured temperatures preferred by skeptics and gathered by scientists at the University of Alabama in Huntsville.
Statisticians who analyzed the data found a distinct decades-long upward trend in the numbers, but could not find a significant drop in the past 10 years in either data set. The ups and downs during the last decade repeat random variability in data as far back as 1880.
Saying there’s a downward trend since 1998 is not scientifically legitimate, said David Peterson, a retired Duke University statistics professor and one of those analyzing the numbers.
Identifying a downward trend is a case of “people coming at the data with preconceived notions,” said Peterson, author of the book “Why Did They Do That? An Introduction to Forensic Decision Analysis.”
1998 was a strong El Nino year—unusually high atmospheric temperatures that year in no way suggests that the earth has stopped heating.
I’m claiming that this one data set does not by itself support rejection of the body of theory that suggests global warming is occurring, and that it is intellectually dishonest to imply that it does.
Well answered (and I have downvoted brazil for trying to coerce you into making a stupid claim with the obvious intent of presenting a misleading dichotomy.)
I’m not sure what the claim “global warming is occuring” means so I can’t really speak to that.
In any event, as I noted in the blog post, the warmists have made specific predictions. The temperature record for the past 10 or so years contradicts some of those predictions.
ETA: Can I take it that your answer to my question is “no”?
I’m not saying the absence of a significant cooling trend is the same thing as the presence of a significant warming trend—that would be a stupid thing to say. As for the remainder: I don’t trust your judgment, but the data you provided is interesting. I will examine the composite NOAA temperature data (ocean, land, and combined) and update accordingly.
(It should be noted, however, that if anthropogenic inputs are significant, as claimed by the climate scientists whose work we are discussing, predicting the climate would require predicting all anthropogenic climate forcings—and therefore we might expect the predictions to be worse than anticipated.)
It should be noted, however, that if anthropogenic inputs are significant, as claimed by the climate scientists whose work we are discussing, predicting the climate would require predicting all anthropogenic climate forcings—and therefore we might expect the predictions to be worse than anticipated.
They can get around this by expressing their predictions as a function of future anthropogenic emissions, thus removing this source of uncertainty.
I’m not saying the absence of a significant cooling trend is the same thing as the presence of a significant warming trend—that would be a stupid thing to say
Correct. Which is why the article you linked to does not contradict the claim I made.
As for the remainder: I don’t trust your judgment, but the data you provided is interesting
Well you shouldn’t trust my judgment. What’s the motto of the British science academy? Something like “Don’t take my word for it.”
Every 10-year trendline in cupholder’s data was increasing.
If you give a statistician the 30-year or 130-year data set with the y-axis label taken off, they will tell you that there is no sign of a levelling-off.
A quick clarification: for each of the data links I posted there, the trendline is calculated based on all of the data that’s shown, i.e. for the post-1998 data the trendline is based on the last twelve years, for the post-1970s data the trendline is based on all of the post-1970s data, and so on. In other words, only the data for the last 10 years of data really have a 10-year trendline.
[ETA: Unless you mean you calculated 10-year trendlines for each data set yourself, in which case feel free to disregard this.]
Here’s a plot of the UAH index from 1998 to 2009.
http://www.woodfortrees.org/plot/uah/from:1998/to:2009/plot/uah/from:1998/to:2009/trend
The linear trend is definitely decreasing for this particular plot.
I’m seriously skeptical of this.
P.S. Are you saying that the absence of significant cooling is the same thing as the presence of significant warming?
Note that changing the beginning data point to either 1997 or 1999 makes the regression line have a positive slope. It’s not at all surprising that there is enough variability that cherry-picking data is possible. Stuffing a positive outlier at the beginning will, of course, tend to do this.
Agreed. I cherry-picked 1998 as a starting point to counter the claim that the data was increasing “in all cases.”
Still, I would also note that as I explain on my blog post, there is some significance to the observation that global surface temperatures still have not exceeded the 1998 high. (According to the majority of leading temperature measurements.)
Did you read the linked article?
[...]
1998 was a strong El Nino year—unusually high atmospheric temperatures that year in no way suggests that the earth has stopped heating.
Yes, and I’m not sure what your point is.
Are you claiming that the absence of a significant cooling trend is the same thing as the presence of a significant warming trend?
It’s a very simple question. Why won’t you answer it?
Incidentally, I wrote a blog post about the article in question which touches on these issues.
http://brazil84.wordpress.com/2009/10/27/more-on-global-cooling/
I’m claiming that this one data set does not by itself support rejection of the body of theory that suggests global warming is occurring, and that it is intellectually dishonest to imply that it does.
Well answered (and I have downvoted brazil for trying to coerce you into making a stupid claim with the obvious intent of presenting a misleading dichotomy.)
In light of the spelling thread, dichotomy? This immediately jumped out at me in the manner that a few others describe for spelling mistakes.
Thankyou. It jumped out at me too upon rereading. I wonder why my browser has stopped spell checking for me.
I’m not sure what the claim “global warming is occuring” means so I can’t really speak to that.
In any event, as I noted in the blog post, the warmists have made specific predictions. The temperature record for the past 10 or so years contradicts some of those predictions.
ETA: Can I take it that your answer to my question is “no”?
I’m not saying the absence of a significant cooling trend is the same thing as the presence of a significant warming trend—that would be a stupid thing to say. As for the remainder: I don’t trust your judgment, but the data you provided is interesting. I will examine the composite NOAA temperature data (ocean, land, and combined) and update accordingly.
(It should be noted, however, that if anthropogenic inputs are significant, as claimed by the climate scientists whose work we are discussing, predicting the climate would require predicting all anthropogenic climate forcings—and therefore we might expect the predictions to be worse than anticipated.)
They can get around this by expressing their predictions as a function of future anthropogenic emissions, thus removing this source of uncertainty.
From the papers I looked at today, a major problem appears to be measuring the forcings that go into the model.
I imagine they do—do we have a climatologist in the house?
I imagine they do too; the question is whether they claim the right to (retroactively) “massage” their predictions, which would invalidate this test.
Correct. Which is why the article you linked to does not contradict the claim I made.
Well you shouldn’t trust my judgment. What’s the motto of the British science academy? Something like “Don’t take my word for it.”