Digital Diatribes

A presentation of data on climate and other stuff

Posts Tagged ‘HadCrut’

April 2012 HadCrut Anomaly

Posted by The Diatribe Guy on May 29, 2012

I will not be updating the charts in the wake of the latest anomaly released, but thought I’d throw out the quick note that it came in at 0.482, which breaks the stretch of lower anomalies over the last number of months. This is the highest the value has been since late 2010.

Posted in HadCrut, Temperature Analysis, Updates | Tagged: , , , | Leave a Comment »

Random Slope Charts – HadCrut

Posted by The Diatribe Guy on May 24, 2012

I’ll put these charts up without much comment. I updated them, so I thought I’d post them. Each one represents the historical slope values for the different trend line lenghts (60, 120, …, 360). I just find it interesting to see how the best-fit trend lines adjust over time and compare where we’re at now to historical values.

60-hc-slopes-history

60-hc-slopes-history

120-hc-slopes-history

120-hc-slopes-history

180-hc-slopes-history

180-hc-slopes-history

240-hc-slopes-history

240-hc-slopes-history

300-hc-slopes-history

300-hc-slopes-history

360-hc-slopes-history

360-hc-slopes-history

Posted in Data, Global Warming, HadCrut, Information, Science, Temperature Analysis, Updates | Tagged: , , , , , , , , | Leave a Comment »

Temperature Trends for the last 360 months – HadCrut

Posted by The Diatribe Guy on May 23, 2012

Here are the latest charts for the HadCrut Global Temperature Anomalies, for the 30 year period ending March 2012.

The Data

What is presented here is the trend over the last 360 months, the slope of which has been in consistent decline over the last eight years. The current slope itself is +.1279. This puts the longer-term trendline of 30 years at a higher slope level than the 20 or 25 year magnitude. If one were to extrapolate this value forward as an expectation of continued warming, it would represent a 1.53 Celsius temperature increase per century. This spurred the question to me as to what starting point in time to current represents the highest current slope. The answer to that is using a starting point of January 1974 (37 years, 3 months), which has a current slope value of 0.13735. Cherry-picking that data point would indicate warming at a rate of 1.65 degrees Celsius per Century. All trend lines shorter than that (starting at least 4 months ago) or longer than than have a smaller slope value.

Chart below:

30 year Trend - HadCrut

Trend Line over Last 360 months – HadCrut

The next chart is simply a point of comparison. The highest slope value in recent years occurred with the 30-year period ending December 2003, at the height of global warming hysteria.

Recent Peak trend line

Peak 360 Month Trend Line

Finally, I show what has transpired with the slopes in recent years with the 30 year trend line. There has been a consistent decline in the slopes since November 2003 of the best-fitted lines. The decline itself is a very close linear fit though not quite as tight as some of the previous charts. There are periods of deceleration and acceleration in the trend, and even some periods where the slope value increases a bit for a time. Similar to the 25-year chart, in the most recent few months you can see it accelerate in its declining value. There is little indication that this decline will halt in the near term. I should explain how I arrive at that statement. I have a spreadsheet set up to emulate future periods, so by simply typing in prospective anomaly values, I can see what the level of the number needs to be in order to put an end to the declining slope values.

By way of exercise, here are the anomaly values needed to keep the slope the same from the current value to some period in the near future:
1) For the slope to remain level as of April 2012 month end, the next anomaly value has to be 52.
2) For the slope to remain level from April to May, the May anomaly needs to be 51.
3) For the slope to remain level from May to June, the June anomaly needs to be 60.
4) For the slope to remain level from June to July, the July anomaly needs to be 57.

None of these values are impossible. However, given the fact that last 20 anomaly readings are under 50, it would seem unlikely to expect such a series of values suddenly emerge.

Trend in recent 360-month slopes

Trend in recent 360-month slopes

Posted in Data, Global Warming, HadCrut, Information, Science, Temperature Analysis, Updates | Tagged: , , , , , , , , | Leave a Comment »

Temperature Trends for the last 300 months – HadCrut

Posted by The Diatribe Guy on May 22, 2012

Here are the latest charts for the HadCrut Global Temperature Anomalies, for the 25 year period ending March 2012.

The Data

What is presented here is the trend over the last 300 months, the slope of which has been in very consistent decline over the last five years. The current slope itself is +.113 (actually a bit less than the 20 year slope). So, at this point, the 25-year trend is still positive

Chart below:

25 year Trend - HadCrut

Trend Line over Last 300 months – HadCrut

The next chart is simply a point of comparison. The highest slope value in recent years occurred with the 25-year period ending February 2007.

Recent Peak trend line

Peak 300 Month Trend Line

Finally, I show what has transpired with the slopes in recent years with the 25 year trend line. There has been a consistent decline in the slopes of the best-fitted lines. The decline itself is a very close linear fit, though in the most recent periods you can see it accelerate in its declining value. There is little indication that this decline will halt in the near term. If I plug the latest 12-month average anomalies the values continue to decline.

Trend in recent 300-month slopes

Trend in recent 300-month slopes

Posted in Data, Global Warming, HadCrut, Information, Science, Temperature Analysis, Updates | Tagged: , , , , , , , , | 2 Comments »

Temperature Trends for the last 240 months – HadCrut

Posted by The Diatribe Guy on May 21, 2012

Here are the latest charts for the HadCrut Global Temperature Anomalies, for the 20 year period ending March 2012.

The Data

What is presented here is the trend over the last 240 months, the slope of which has been in very consistent decline over the last eight years. The current slope itself is +.1228. Sp, at this point, the 20-year trend is still positive, even though the last 15 year trend line is slightly negative. This is due to the first five years of the period (1992-97) exhibiting lower anomalies than current averages. That said, the current slope is the lowest value for a 20 year trend line fitted since the period ending June 1998.

Chart below:

20 year Trend - HadCrut

Trend Line over Last 240 months – HadCrut

The next chart is simply a point of comparison. The highest slope value in recent years occurred with the 20-year period ending June 2004.

Recent Peak trend line

Peak 240 Month Trend Line

Finally, I show what has transpired with the slopes over the last number of years with the 20 year trend line. There has been a consistent decline in the slopes of the best-fitted lines. The decline itself is a very close linear fit. There is little indication that this decline will halt in the near term. If I plug the latest 12-month average anomalies into each of the next 6 months, we see this trend line dipping below the 0.10 mark in 6-7 months.

Trend in recent 240-month slopes

Trend in recent 240-month slopes

Posted in Data, Global Warming, HadCrut, Information, Science, Temperature Analysis, Updates | Tagged: , , , , , , , , | Leave a Comment »

Temperature Trends for the last 180 months – HadCrut

Posted by The Diatribe Guy on May 17, 2012

Here are the latest charts for the HadCrut Global Temperature Anomalies, for the 15 year period ending March 2012.

The Data

What is presented here is the trend over the last 180 months, the slope of which has been in very consistent decline over the last five years. The current slope itself is -.0106, and it is the second month in which the trend line is negative. The current slope is the lowest value for a 15 year trend line fitted since February 1977 (back when people were concerned about another ice age).

Chart below:

15 year Trend - HadCrut

Trend Line over Last 180 months – HadCrut

The next chart is simply a point of comparison. The highest slope value in recent years occurred with the 15-year period ending February 2007.

Recent Peak trend line

Peak 180 Month Trend Line

Finally, I show what has transpired with the slopes over the last number of years with the 15 year trend line. There has been a consistent decline in the slopes of the best-fitted lines. The decline itself is a very close linear fit. There is little indication that this decline will halt in the near term. If I plug the latest 12-month average anomalies into each of the next 6 months, we see this trend line dipping below the -0.03 mark.

Trend in recent 180-month slopes

Trend in recent 180-month slopes

Posted in Data, Global Warming, HadCrut, Information, Science, Temperature Analysis, Updates | Tagged: , , , , , , , , | 1 Comment »

Quick hit on the impact of the May HadCrut anomaly

Posted by The Diatribe Guy on June 29, 2011

Now that I have everything updated for April month-end, I just checked the HadCrut data set and see that they have released the May anomaly of 0.322.

This is actually a slightly lower value than the 12-month average value I had been using for my comments on the impact of future trend lines.

As I was reviewing, I am embarrassed once again to note an error that I uncovered in the process: that my 60-month chart was actually a 50-month chart. When corrected, the current slope on the 60-month chart is actually only 0.0167 at paril month end (nearly flat). This value was properly reflected on the slope charts, but not on the raw data chart. I will edit the post(s) as appropriate to reference that.

Anyway, I am not going to update all the charts, but thought I’d plunk in the new anomaly (caveat: I did not refresh the entire data set, and this will not account for any historical adjustments to the data). Here are the results:

60-month trend line has gone negative: slope = -0.009517. Expect a larger drop in this over the next two months. Equivalent of 0.006 degrees of total cooling over that period.

120-month trend line: Went more deeply negative. Slope = -0.064081. Equates to 0.077 degrees cooling over the last ten years.

180-month trend line: Slope dropped to 0.049704, the equivalent of 0.089 degrees warming over the entire period.

240-month trend line: Slope dropped to 0.138774, the equivalent of 0.333 degrees warming over that 20-year period.

300-month trend line: Slope dropped to 0.129338, the equivalent of 0.388 degrees warming over that 25 year period.

360-month trend line: Slope dropped to 0.134971, the equivalent of 0.486 degrees warming over that 30 year period.

With the new anomaly, the current longest trend line back that demonstrates a negative slope is still 14 years (June 1997 – May 2011).

Posted in Climate Change, Data, Earth, Global Warming, HadCrut, Science, Temperature Analysis | Tagged: , , , , , , , | 7 Comments »

360-Month HadCrut trends as of April month-end 2011

Posted by The Diatribe Guy on June 29, 2011

Today I present the 360-month charts using the most recent HadCrut data.

The 360-month trend line is positive, with a slope of 0.1356, which translates to a temperature change of approximately 0.49 degrees Celsius over the course of 30 years.

Now that I’ve looked at all the different charts and see warming of 0.49 degrees over a 30 year period, here’s how it appears to break down by period:
May 1981 – Apr 1986: +0.10 degrees Celsius contribution to increase
May 1986 – Feb 1991: +0.05 degrees Celsius contribution to increase
May 1991 – Apr 1996: +0.24 degrees Celsius contribution to increase
May 1996 – Apr 2001: +0.17 degrees Celsius contribution to increase
May 2001 – Feb 2007: -0.18 degrees Celsius contribution to increase
Mar 2007 – Apr 2011: +0.11 degrees Celsius contribution to increase*
* – Due to an original error in the presented 60-month chart only being 50 months, the dates do not represent an equal 5-year span. The actual 5 year span was near zero. The previous 5 year period would adjust accordingly.

I’ve discussed the “step function” that seems to have taken place in 1996-97. While not presented here, a much better fit to describe the “trend” in global temperature, simply by observation, is to fit a line from 1981 to 1997-ish and then from that point forward. The best fits of those independent lines would show a very notable jump occurring at that point.

Chart below:

360-month Trend in Global Temps - HadCrut

360-month Trend in Global Temps - HadCrut

SLOPE CHANGES
In the chart below, we see the latest series of 30-year slope values since 2003. There was a steady decline in the slope value into 2009 that met the .1300 line, but has since increased to the current levels. The trend line is responding to a “fulcrum” of sorts. What I mean by that is that, even though lower anomalies are dropping off the left side of the chart (which normally would imply a lowering of the trend line) this is outweighed by anomalies on the right side of the chart staying up around the last decade’s average, and this is because of that step function that is now reaching the mid-point of the chart. If future anomalies stay around where they are at now, then when that fulcrum point moves to the left side of the chart, we will see that trend line slope value decline. We wouold not expect to see the 30 year trend line go negative unless there is a prolonged stretch of declining anomalies. Even in that scenario, it will take years to move that line around.

Chart below:

Trend of 360-month Slope values in Global Temps - HadCrut

Trend of 360-month Slope values in Global Temps - HadCrut

The entire history of 360-month slopes is shown in the chart below:

There has not been a negative trend line in the 30-year charts since the period ending November 1972. We won’t reasonably be expecting a negative trend line for another few years, even under a cooling scenario. What we can probably expect to see, however, is the slope in the trend line start to decrease soon. The slope will probably be fairly steady over the next 3-5 months, and then we’ll see some lower values emerge. In my estimation (assuming average 12-month anomaly values) we’ll see the slope on the trend line fall below 0.13 around march 2012, thus continuing the downtrend and slope values we’ve seen since 2003. We haven’t seen a slope under 0.13 in the 30-year line since April 1999.

Chart below:

History of 360-month Slope values in Global Temps - HadCrut

History of 360-month Slope values in Global Temps - HadCrut

Posted in Climate Change, Cycles, Data, Earth, Global Warming, HadCrut, Information, Science, Temperature Analysis, Updates | Tagged: , , , , , , , , , | Leave a Comment »

300-Month HadCrut trends as of April month-end 2011

Posted by The Diatribe Guy on June 28, 2011

Today I present the 300-month charts using the most recent HadCrut data.

The 300-month trend line is positive, with a slope of 0.1311, which translates to a temperature change of approximately 0.39 degrees Celsius over the course of 25 years. It’s kind of interesting to see the breakdown of the warming by looking at the different trend-lines. The 15-year chart ending in the current period attributes 0.10 degrees in temperature change in total over the last 15 years. The 20-year trend line tells us that total warming over the last 20 years equals 0.34 degrees. So, in that five year period from 1991-1996, we see a period of anomalies that were lower than both preceding and succeeding periods, which drives the slope higher on that trend line and tells us that 0.24 degrees of the 0.34 degrees can be blamed on that time period’s lower anomalies. The current slope value of the 25 year trend line adds 0.05 degrees to the total warming, so the 5 year period from 1986-91 only accounts for a total of about 0.01 degrees Celsius per year.

Chart below:

300-month Trend in Global Temps - HadCrut

300-month Trend in Global Temps - HadCrut

SLOPE CHANGES
In the chart below, we see the latest series of 25-year slope values since 2007. There has been a steady decline in the slope value, with only a short lull (flat) in 2008. In the last half-year, the rate at which the trend line is decreasing has accelerated as some older, lower anomalies drop off the front end. The last time the slope value has reached current levels was January 2002.

In all likelihood, the 25-year trend line will remain positive for the next few years to come. In a scenario of just using a 12-month average going forward, the trend line would not become negative until 2020. Obviously, if temperature readings decline that would accelerate. If temps drift upward, it’s possible that we won’t see a 25-year trend line reach zero or negative at all.

Chart below:

Trend of 300-month Slope values in Global Temps - HadCrut

Trend of 300-month Slope values in Global Temps - HadCrut

The entire history of 300-month slopes is shown in the chart below:

There has not been a negative trend line in the 25-year charts since March 1969. Now, more than 42 years later, we will not reasonably expect any possibility of seeing a negative slope for at least another 5 years or more. Things got real close in 1976, but at its low point the trend stayed slightly positive.

Looking at the history, the last prolonged stretch above zero trend started in January 1922 and lasted until July 1954. That was a stretch of 32.5 years, so we are well past that at this point. We are in a period where the current retracement is the largest since 1976, but despite that we are still well above the zero line.

Chart below:

History of 300-month Slope values in Global Temps - HadCrut

History of 300-month Slope values in Global Temps - HadCrut

Posted in Climate Change, Cycles, Data, Earth, Global Warming, HadCrut, Information, Science, Temperature Analysis, Updates | Tagged: , , , , , , , , | 4 Comments »

240-Month HadCrut trends as of April month-end 2011

Posted by The Diatribe Guy on June 24, 2011

Today I present the 240-month charts using the most recent HadCrut data.

The 240-month trend line is positive, with a slope of 0.1399, which translates to a temperature change of approximately 0.34 degrees Celsius over the course of 20 years. This is fairly significant warming over that period. Since the 15-year chart shows less than a third of that amount in total warming, the majority of the slope value is attributable to the lower anomalies in the first five years. The current slope value of the 20 year trend line is at about the same level as it’s been for the last year and a half or so. It would certainly appear that if temperatures do not dramatically increase, the slope value will decrease as some of those lower anomalies drop off. Every single anomaly for the next three years is lower than every anomaly since mid-2001. However, since no anomalies have since exceeded the peak value in 1998, the trend line certainly looks to have a high probability of decreasing in slope.

Chart below:

240-month Trend in Global Temps - HadCrut

240-month Trend in Global Temps - HadCrut

CORRECTION ON CURRENT FLAT/COOLING TREND

As I was reviewing the above chart, and eyeballing the data since 1997, I was a bit surprised that there wasn’t a trend line that was flat or negative going back to 1997/98. So, I went back to the data and am embarrassed to say that there is. In my first post back after a long hiatus, I didn’t offer my best work, apparently.

Extending a trend line backwards from April month-end, the best fit trend line does in fact switch from negative to positive between July and August 2000. What I missed was that there is a stretch from May 1997 to November 1997 where the best fit trend line is negative. In other words, we can extend a negatively sloped trend line back in the HadCrut data to May 1997. That is exactly 14 years (which better explains why it looks like the 15-year trend line will go negative within the next year).

I know that there are issues with linear fit and all that stuff, but when the current line goes back 14 years, you’d think that would make some people pause a bit and wonder where this exponential warming is.

My apologies for the erroneous statement in my initial post of this series. I suppose I’ll need to update that chart with May month-end data.

SLOPE CHANGES
In the chart below, we see the latest series of 20-year slope values since 2004. There was a steady decline in the slope value until late 2009, at which point it’s vaccilated around where the current value is. Unless temperature anomalies start to meet and exceed the 1998 peak, we can expect a continued decline in the slope value. Since longer-period slopes take a longer time to adjust, we will need to see anomalies around current averages for the next 5 years or so before we’d see an actual declining trend line. If temperatures drop, this would obviously accelerate. Likewise, if temperatures spurt upwards, we may not see a negative trend line at all in the foreseeable future. Even under a very aggressive cooling scenario, it would take nearly three years to see a negative trend line. So, like it or not, global warming proponents will be able to use 20+ year trend lines to make their point for a few years.

Chart below:

Trend of 240-month Slope values in Global Temps - HadCrut

Trend of 240-month Slope values in Global Temps - HadCrut

The entire history of 240-month slopes is shown in the chart below, with the following observations:

There has not been a negative trend line in the 20-year charts since February 1979. Now, more than 32 years later, we will not reasonably expect any possibility of seeing a negative slope for at least another 3 years.

Looking at the history, the last prolonged stretch above zero trend started in October 1919 and lasted until August 1950. That was a stretch of almost 31 years, a length of time we’ve already passed. It will be interesting to see if a downward plunge is in store for us, as a cyclical mindset might think is the case. However, even with a cyclical mindset, it has to be recognized that we’re comparing to exactly one previous similar cycle, so it’s hardly a credible sample.

Chart below:

History of 240-month Slope values in Global Temps - HadCrut

History of 240-month Slope values in Global Temps - HadCrut

Posted in Climate Change, Cycles, Data, Earth, Global Warming, HadCrut, Information, Science, Temperature Analysis, Updates | Tagged: , , , , , , , , , | 1 Comment »