It is absolutely true. That's why CRU Director Phil Jones said so...
<QUOTE>
Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995
By Jonathan Petre
Last updated at 5:12 PM on 14th February 2010
[...]
He further admitted that in the last 15 years there had been no ‘statistically significant’ warming, although he argued this was a blip rather than the long-term trend.
The Daily Mail
</QUOTE>
The no “statistically significant” warming since 1995 comment certainly was a bombshell… But, what exactly does he mean by “statistically significant”?
A plot of the HadCRUT3 temperature series since 1995 certainly seems to show a warming trend…
However, this trend is not “statistically significant.” The correlation coefficient (or r-squared) value is only 0.13. This means that only 13% of the data fit the linear trend. Or, more correctly put: The linear trend only explains 13% of the temperature change since 1995.
If we include the El Niño-warmed past few months, the global trend since 1998 becomes very slightly positive; but the r-squared is only 0.0061. Less than 1% of the temperature change since 1998 is explained by the linear trend. The Southern Hemisphere has cooled slightly and the Northern Hemisphere has warmed slightly since 1998; but neither trend is statistically significant.
The r-squared of a linear trend line of this partial sine wave is 0.88… 88% of the data fit the trend line. This implies a very strong secular trend; yet, we know that in reality sine waves do not have secular trends.
If we take the entire HadCRUT3 series and apply a linear trend line, we get an apparent secular trend…
How can such a clear secular trend vanish like that? The answer is easy. Each “up hill” and each “down hill” leg of a sine wave has a very strong secular trend. Unless you have enough data to see several cycles, you don’t know if you are looking at a long-term trend or an incomplete cycle. There's no trend at all since 1998 (just like there's no trend at the peak or trough of a sine wave). There is a warming trend from 1995-2010; but it is statistically insignificant (just like the shoulders of the peaks and troughs of sine waves). There is a statistically significant warming trend from 1600-2010 (just like from a trough to a peak of a sine wave). There's no trend at all from 1 AD to 2010 AD (just like there's no trend through multiple cycles of a sine wave).
This is the "Goldilocks Phenomenon." If you use too little data, the warming trend goes away. If you use too much data, the warming trend goes away. If you use just the right amount of data, you have a warming trend.
That is categorically false. "The hottest 12-month period ever recorded was from June 2009 to May 2010.....2005 was the hottest year globally, and 2009 the second hottest."
How did you come up with the notion that there has been no statistically significant warming since 1995? Take a look at the NASA graphs.....
I think you know very well that the reference is to the arbitrary 95% probability cut-off, that the years chosen (1995 through 2009) were cherry picked, that whether the 95% cut-off was met even then depends on what data set you take, and that in any data set between 1995 and the present, there has indeed been 95% "statistically significant" warming.
This is quite apart from the overall long-term trends, as discussed by Trevor.
So what's your point?
Edit: David "Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995
When a person who has made it into the political arena and has become very well known solely because of AGW, like Phil Jones, says it is true, I have to look at the fools pretending that this is not true in shock and awe. The fact that they are not even wiling to admit this is truly stupid. IF they feel so strongly that Phil Jones does not know what he is talking about, then they could at least stop referencing him and his work all of the time.
You can make the claim that it is cherry-picking, but that claim can and will always be made on both sides. Both sides use the analysis that best represents their side. There is some warming occurring, we shoudl work to lessen CO2, but the end of the world is certainly not coming. We are not killing the environment, we will not flood the world. As with everything though, we should be working towards improvement. I tend to think that the less we place out into the atmosphere, the better, but I am certainly not willing to see my electric bill triple so that we can keep the world from heating up by 0.01 degree.
Willingness to exagerrate and scare are done to get money, willingness to say absolutely nothing should change are done to not lose money. Good decisions are made by understanding the facts free of bias and fear.
Paul B,
The "arbitrary" .05 cutoff is the same cutoff used in nearly every scientific field. Are you really complaining about 0.05 cutoff? How biased do you have to be to only complain about this cutoff when it affects your pet theory?
To better understand what cherry picking is about, lets look at the temps going back different time points:
100 years ago - ~0.74 degree cooler
1000 years ago - ~ the same
10,000 years ago - ~ 1 degree cooler
100,000 years ago - ~1.5 degree cooler
1,000,000 years ago ~0.8 degree cooler
10,000,000 years ago ~ 1.5 degrees warmer
100,000,000 years ago ~ 4 degrees warmer
500,000,000 years ago ~7 degrees warmer
Which number do you want to cherry pick? Honestly I don't trust any number from 1000 or more years ago within +-.5 degree. I also do not see the 7 degree increase that some warmers scare us with as even being a remote possibility.
Dana,
The 93% confidence level means that is you resampled an infinite amount of time using the same methodology, then 93% of your confidence intervals would contain the true value. It DOES NOT mean that you are 93% confident that the answer is within the interval. That is a credible set which is only seen when using Bayesian techniques, which I can assure you, they did not do. Either way though, it does not matter. Either you proclaim the CI that you are going to use prior to testing, or you use the 95% CIs that are standard with science. YOU DO NOT PRETEND THAT 93% CIs ARE ACCEPTABLE IF NOT STATED APRIORI!!!!
He tells these teens to check any of the leading sites that gather data.
I don't think he really fooled these teens but if you do check, you find that NOAA has 2005 listed as the warmest year with NOAA 1998 is listed as second the CRU have 1998 as the warmest and 2005 as the second warmest.
Of course as with much of what mockingtone says he takes part of the truth but leaves out parts that would show what he is saying is total BS.
1998 for a start is 12 years ago 2005 is just 5 years ago, 2009 (the 5th warmest year on record is just last year) I'm not really sure how you can work a 5th warmest year into a claim 15 years of cooling.
Even with 1998 what he fails to mention is that the period of mid 1997 through 1998 had the strongest El Nino of the last century (which two years are still in the top ten that are not in the 2000s, 1997 & 1998)
You can see that in the temperature record 1998 is well above the trend rise in temperature, but what is also pretty obvious is that temps since have been very close to that 1998 level, without the help of a such a strong El Nino.
Four of the first 6 months of 2010 recorded 1st's in average global temp (warmer than 1998) it is likely temps will dip a little as a cool phase La Nina takes effect, but even so it is very likely 2010 will still be warmer than 2009.
On NOAAs (year to date) data up to the end of July 2010 is still the 1st warmest year on record at 0.68°C (1.22°F) above the 20th century average
As anyone with a knowledge of maths would know the larger the period of data the more accurate the stat' the average temperate above the mean for the decade of the 1990s is 0.36°C (0.65°F) the same average for the 2000s is 0.54°C (0.96°F) above the average, there is no doubt at all that is warmer.
It should also be said the the difference between these two figures is higher than the IPCCs estimate of average decadal temperature rise.
bravojim:
I don't don't think it even needs to be said any longer that you are not a scientist (of any type) your own words show that far better than anything I could say.
Even their guru, Phil Jones, tells them that there isn't any statistically significant warming, but they refuse to believe it. There is so much random variation in the climate that it cannot be demonstrated that the climate is still warming in the period 1995 to the present.
If it turn out that the climate is warming, it is still to be demonstrated that human activity is the driver.
What Phil Jones said is that the warming between 1995 and 2009 was just short of statistically significant at the 95% confidence level because statistical significance is less likely with such a short period. Now with the additional warming in the first half of 2010 the warming is certainly statistically significant.
It *was* true *if* you only use the Hadley Centre's global temperature data (rather than NASA's, for example), as of the end of 2009. However, the planet has continued to warm in 2010 (which is on pace to be in the top 2 hottest years on record), so the statement is no longer true even using Hadley data.
The original statement was also only true at a 95% confidence level. The warming trend was statistically significant in Hadley data at a 93% confidence level (meaning you could say with 93% certainty that there was a warming trend).
It probably depends if you base your data on GISS or CRU. CRU is almost certainly biased but I won't go into that. Even with using essentially the same biased data, he wasn't willing to adjust them or cook them to the point that he saw statistically significant warming. Phil Jones stated that precisely and he is leftist alarmist. He also doesn't agree with the recent bogus way that Hansen is cooking the books. The cherry pickers are leftist activists that ignore anyone except the them most extreme political hack activists. . I guess you have to overdose on the Kool aid like Hansen, who is obviously completely nuts in the head, to be credible to alarmists. Taking Phil Jones on his words is cherry picking. It is probably stupid to rely on a Kool aid drinker like Jones but it bizarre that leftists call that cherry picking.
Answers & Comments
Verified answer
It is absolutely true. That's why CRU Director Phil Jones said so...
<QUOTE>
Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995
By Jonathan Petre
Last updated at 5:12 PM on 14th February 2010
[...]
He further admitted that in the last 15 years there had been no ‘statistically significant’ warming, although he argued this was a blip rather than the long-term trend.
The Daily Mail
</QUOTE>
The no “statistically significant” warming since 1995 comment certainly was a bombshell… But, what exactly does he mean by “statistically significant”?
A plot of the HadCRUT3 temperature series since 1995 certainly seems to show a warming trend…
http://i90.photobucket.com/albums/k247/dhm1353/Cli...
However, this trend is not “statistically significant.” The correlation coefficient (or r-squared) value is only 0.13. This means that only 13% of the data fit the linear trend. Or, more correctly put: The linear trend only explains 13% of the temperature change since 1995.
From 1998-2009, the data show no trend at all…
http://i90.photobucket.com/albums/k247/dhm1353/Cli...
If we include the El Niño-warmed past few months, the global trend since 1998 becomes very slightly positive; but the r-squared is only 0.0061. Less than 1% of the temperature change since 1998 is explained by the linear trend. The Southern Hemisphere has cooled slightly and the Northern Hemisphere has warmed slightly since 1998; but neither trend is statistically significant.
http://i90.photobucket.com/albums/k247/dhm1353/Cli...
One of the “problems” with the way climate data are handled is in the obsession with applying linear trend lines to non-linear data.
A sine wave has no linear trend…
http://www.woodfortrees.org/graph/sine:10
But… What happens if my data represent only a portion of a sine wave pattern?
http://i90.photobucket.com/albums/k247/dhm1353/Cli...
The r-squared of a linear trend line of this partial sine wave is 0.88… 88% of the data fit the trend line. This implies a very strong secular trend; yet, we know that in reality sine waves do not have secular trends.
If we take the entire HadCRUT3 series and apply a linear trend line, we get an apparent secular trend…
http://i90.photobucket.com/albums/k247/dhm1353/Cli...
The r-squared is 0.55… 55% of the data fit the secular trend. This implies that there is a real long-term warming trend.
What happens to that secular trend if we expand our time series like we did with the sine wave?
The apparent secular trend vanishes in a puff of mathematics…
http://i90.photobucket.com/albums/k247/dhm1353/Mob...
How can such a clear secular trend vanish like that? The answer is easy. Each “up hill” and each “down hill” leg of a sine wave has a very strong secular trend. Unless you have enough data to see several cycles, you don’t know if you are looking at a long-term trend or an incomplete cycle. There's no trend at all since 1998 (just like there's no trend at the peak or trough of a sine wave). There is a warming trend from 1995-2010; but it is statistically insignificant (just like the shoulders of the peaks and troughs of sine waves). There is a statistically significant warming trend from 1600-2010 (just like from a trough to a peak of a sine wave). There's no trend at all from 1 AD to 2010 AD (just like there's no trend through multiple cycles of a sine wave).
This is the "Goldilocks Phenomenon." If you use too little data, the warming trend goes away. If you use too much data, the warming trend goes away. If you use just the right amount of data, you have a warming trend.
That is categorically false. "The hottest 12-month period ever recorded was from June 2009 to May 2010.....2005 was the hottest year globally, and 2009 the second hottest."
How did you come up with the notion that there has been no statistically significant warming since 1995? Take a look at the NASA graphs.....
I think you know very well that the reference is to the arbitrary 95% probability cut-off, that the years chosen (1995 through 2009) were cherry picked, that whether the 95% cut-off was met even then depends on what data set you take, and that in any data set between 1995 and the present, there has indeed been 95% "statistically significant" warming.
This is quite apart from the overall long-term trends, as discussed by Trevor.
So what's your point?
Edit: David "Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995
http://www.dailymail.co.uk/news/article-%E2%80%A6%... quotes what he must know to be a factually incorrect deadline in a newspaper report of the relevant BBC interview. Is David statistically significant?
When a person who has made it into the political arena and has become very well known solely because of AGW, like Phil Jones, says it is true, I have to look at the fools pretending that this is not true in shock and awe. The fact that they are not even wiling to admit this is truly stupid. IF they feel so strongly that Phil Jones does not know what he is talking about, then they could at least stop referencing him and his work all of the time.
You can make the claim that it is cherry-picking, but that claim can and will always be made on both sides. Both sides use the analysis that best represents their side. There is some warming occurring, we shoudl work to lessen CO2, but the end of the world is certainly not coming. We are not killing the environment, we will not flood the world. As with everything though, we should be working towards improvement. I tend to think that the less we place out into the atmosphere, the better, but I am certainly not willing to see my electric bill triple so that we can keep the world from heating up by 0.01 degree.
Willingness to exagerrate and scare are done to get money, willingness to say absolutely nothing should change are done to not lose money. Good decisions are made by understanding the facts free of bias and fear.
Paul B,
The "arbitrary" .05 cutoff is the same cutoff used in nearly every scientific field. Are you really complaining about 0.05 cutoff? How biased do you have to be to only complain about this cutoff when it affects your pet theory?
To better understand what cherry picking is about, lets look at the temps going back different time points:
100 years ago - ~0.74 degree cooler
1000 years ago - ~ the same
10,000 years ago - ~ 1 degree cooler
100,000 years ago - ~1.5 degree cooler
1,000,000 years ago ~0.8 degree cooler
10,000,000 years ago ~ 1.5 degrees warmer
100,000,000 years ago ~ 4 degrees warmer
500,000,000 years ago ~7 degrees warmer
Which number do you want to cherry pick? Honestly I don't trust any number from 1000 or more years ago within +-.5 degree. I also do not see the 7 degree increase that some warmers scare us with as even being a remote possibility.
Dana,
The 93% confidence level means that is you resampled an infinite amount of time using the same methodology, then 93% of your confidence intervals would contain the true value. It DOES NOT mean that you are 93% confident that the answer is within the interval. That is a credible set which is only seen when using Bayesian techniques, which I can assure you, they did not do. Either way though, it does not matter. Either you proclaim the CI that you are going to use prior to testing, or you use the 95% CIs that are standard with science. YOU DO NOT PRETEND THAT 93% CIs ARE ACCEPTABLE IF NOT STATED APRIORI!!!!
The quote as presented is from Lord Mockingtone, word for word.
Here he tries to bully some teens and uses the phase "no warming in 15 years"
http://www.youtube.com/watch?v=ne-X_vFWMlw
He tells these teens to check any of the leading sites that gather data.
I don't think he really fooled these teens but if you do check, you find that NOAA has 2005 listed as the warmest year with NOAA 1998 is listed as second the CRU have 1998 as the warmest and 2005 as the second warmest.
http://www.ncdc.noaa.gov/sotc/?report=global&year=...
Of course as with much of what mockingtone says he takes part of the truth but leaves out parts that would show what he is saying is total BS.
1998 for a start is 12 years ago 2005 is just 5 years ago, 2009 (the 5th warmest year on record is just last year) I'm not really sure how you can work a 5th warmest year into a claim 15 years of cooling.
Even with 1998 what he fails to mention is that the period of mid 1997 through 1998 had the strongest El Nino of the last century (which two years are still in the top ten that are not in the 2000s, 1997 & 1998)
http://climate.nasa.gov/keyIndicators/index.cfm#Gl...
You can see that in the temperature record 1998 is well above the trend rise in temperature, but what is also pretty obvious is that temps since have been very close to that 1998 level, without the help of a such a strong El Nino.
Four of the first 6 months of 2010 recorded 1st's in average global temp (warmer than 1998) it is likely temps will dip a little as a cool phase La Nina takes effect, but even so it is very likely 2010 will still be warmer than 2009.
On NOAAs (year to date) data up to the end of July 2010 is still the 1st warmest year on record at 0.68°C (1.22°F) above the 20th century average
http://www.ncdc.noaa.gov/sotc/?report=global&year=...
As anyone with a knowledge of maths would know the larger the period of data the more accurate the stat' the average temperate above the mean for the decade of the 1990s is 0.36°C (0.65°F) the same average for the 2000s is 0.54°C (0.96°F) above the average, there is no doubt at all that is warmer.
It should also be said the the difference between these two figures is higher than the IPCCs estimate of average decadal temperature rise.
bravojim:
I don't don't think it even needs to be said any longer that you are not a scientist (of any type) your own words show that far better than anything I could say.
These AGW believers are the real denailists.
Even their guru, Phil Jones, tells them that there isn't any statistically significant warming, but they refuse to believe it. There is so much random variation in the climate that it cannot be demonstrated that the climate is still warming in the period 1995 to the present.
If it turn out that the climate is warming, it is still to be demonstrated that human activity is the driver.
What Phil Jones said is that the warming between 1995 and 2009 was just short of statistically significant at the 95% confidence level because statistical significance is less likely with such a short period. Now with the additional warming in the first half of 2010 the warming is certainly statistically significant.
No it's not true.
It *was* true *if* you only use the Hadley Centre's global temperature data (rather than NASA's, for example), as of the end of 2009. However, the planet has continued to warm in 2010 (which is on pace to be in the top 2 hottest years on record), so the statement is no longer true even using Hadley data.
The original statement was also only true at a 95% confidence level. The warming trend was statistically significant in Hadley data at a 93% confidence level (meaning you could say with 93% certainty that there was a warming trend).
http://www.cs.princeton.edu/courses/archive/fall01...
Scroll down to "gee whiz" graphs.
The data of change is so slight, and it's "adjusted" so it could be made to look like almost anything.
And 15 years is a statistically insignificant period of time if you look at the earth... not so much if you look at the "record."
It probably depends if you base your data on GISS or CRU. CRU is almost certainly biased but I won't go into that. Even with using essentially the same biased data, he wasn't willing to adjust them or cook them to the point that he saw statistically significant warming. Phil Jones stated that precisely and he is leftist alarmist. He also doesn't agree with the recent bogus way that Hansen is cooking the books. The cherry pickers are leftist activists that ignore anyone except the them most extreme political hack activists. . I guess you have to overdose on the Kool aid like Hansen, who is obviously completely nuts in the head, to be credible to alarmists. Taking Phil Jones on his words is cherry picking. It is probably stupid to rely on a Kool aid drinker like Jones but it bizarre that leftists call that cherry picking.