So many graphs and information. Which one do you believe is right?

Question

The news is now showing new information that shows completely different temperature data.

When given two sets of contradictory data, how do you choose which one to believe? Do you just accept the UN's report because it comes from the UN? Or do you accept data that fits in to what you already believe? Or if you have conflicting data, do you hold off making a decision until more studies are done to determine which one is right?

I'm confused. You can find anything on the internet to support what you want to believe.

Picture of the new temperature graph:
http://farm3.static.flickr.com/2392/2047251195_13655e6124.jpg?v=0

Full report:
http://www.ncasi.org/publications/Detail.aspx?id=3025

Raw data file:
http://www.ncasi.org/programs/areas/climate/LoehleE&E2007.csv

Answer 1

Take your pick. All this information is for you to choose which one fits what you already believe.

You can find all the information you need to back up what ever position you want when it comes to this global warming BS.

Answer 2

Unfortunately, some people have an agenda so they generally start the graph at the point that will show the most warming. If you have a graph that goes back a million or even 10,000 years, the warming isn't all that significant. The same is true for CO2 which has become the cause celeb "pollutant." I could not see two of your charts (the last two) but I thought the first one seemed interesting and had a scale that was long enough to be useful. Too often, graphs are skewed or they meaning is exaggerated.

Answer 3

It's a very good question Mary but I really need to answer it twice.

SHORT ANSWER

The 'new' temperature graphs are excellent, they confirm everything we already known about global warming and match accurately with graphs from the UN and other reliable sources.

Because of the mathematical processes used the 'new' graphs end in 1980, if they are continued to 2007 they match the more familiar temperature graphs and show the recent record warming and highest recorded temperatures.


LONGER, MORE DETAILED ANSWER

The graphs you refer to are the work of Dr Craig Loehle. What he's done is to reconstruct the historical temperature record in much the same way that the UN and other organisations do but by adopting a different approach.

Conventional temperature records include an element of dendroclimatological temperature reconstruction (calculating past temperatures from the analysis of tree rings). There has been some controversy over this method with some people claiming it to be unreliable. Loehle ignored the tree ring record and composed his charts from the analysis of 18 other datasets.

Because of incompatabilites between the datasets he had to apply a unique method of presenting the information (ordinarily temperatures are expressed as an anomaly against a base period mean but because the 18 datasets had no common chronological range he calculated a base period for the full range for each dataset and averaged them all out - different but still accurate).

I've looked closely at his work, the graphs, the mathematics, the science and the process behind them - faultless. Dr Loehle has done a fantastic job, the data hasn't been manipulated in any way and he's composed a very worthwhile set of results.

But... and it's a big but... the graph ends 27 years ago. If we continue the graph to the present day using the identical process as used by Loehle it perfectly matches all the other reliable temperature graphs.


A LOOK AT THE NUMBERS

Loehle uses 2000 years worth of data from which he takes a mean to create a data range from 1 to 1995AD, to this is applied 30 year smoothing giving a final range of 16 to 1980AD – this is what’s plotted on the graphs.

Because of inconsistencies in the 18 source datasets he has had to calculate a base period unique to his graphs, unfortunately his text doesn’t provide an absolute temperature value thus making it incomparable with the conventional temperature records (in short, his zero is not the same as zero on other graphs). It’s not a problem, it just means there’s more numbers to calculate.

The last value on his graph (1980) has an anomalous average value of approx 0.18°C and an extreme of 0.49°C. Using his process of a 30 year running mean applied to an average across more recent datasets shows that in 1980 the average global temp anomaly was 0.085°C, by 1992 (the most recent year to which a 30 year mean can be applied) the temperature anomaly was 0.308°C, by interpolation we can deduce a value for 2007 of 0.565°C i.e. 0.308 + ((0.308 – 0.085 / (1992-1980+1)) x (2007-1992)) = 0.565.

By following Loehle’s method we find that since 1980 the ave global temp has increased by 0.480°C (0.565 – 0.085).

If we extend Loehle’s graph to 2007 we get an anomalous average value of approx 0.660°C (0.180 + 0.480) and an extreme of 0.970°C (0.490 + 0.480). Thus, temperatures are higher now than has ever before been known and currently about 0.2°C higher then the climax of the MWP (note: the process of interpolation has played down the accelerated warming observed during the period of interpolationally derived data and as such a balancing figure of approx 0.1°C should be added to the final figures).

What’s especially pleasing here is that I’m currently working on what we believe to be the most accurate, extensive and user friendly global temperature record. The UN uses one method of data analysis, we use another, Loehle uses a third and the consistency between the three is amazing. The difference between the three systems is a minute one with current temperatures falling within 0.02°C of each other, record temperatures having been reached in 1992 (UN and us) or 1991 (Loehle) and the Medieval Warm Period being 0.3°C cooler than it is now.

Answer 4

Your questions have moved from confrontational to honest inquiry. Starred.

It can be difficult. One needs to spend a lot of time on this, examining many sources, and making judgments.

Read the full article and you'll find stuff like:

"Shifting time series based on some reference decade such as the 1970s (as is commonly done) implicitly assumes that a decade long interval is sufficient to properly line up series with different scales of fluctuation and different noise structures, an assumption that is not tested and which I do not believe is valid."

In other words he's saying I'm right and everyone else is wrong. That raises a flag for me.

You also have to consider the source. Energy and Environment is a rather strange journal. Again, you can take that too far but there's unusual stuff like this:

"On our Energy and Environment paper from 1999, had we known then how that outlet would evolve beyond 1999 we certainly wouldn't have published there. The journal is not carried in the ISI and thus its papers rarely cited."

That from Roger Pielke Jr., a skeptic.

This stuff requires work, and many won't do it. You seem to not be troubled by that. I think that if you do the work, you'll see the mainstream view is correct, but just being willing to work at it is admirable, no matter what you decide.

If everyone did that, this wouldn't be a problem.

EDIT - I, of course, yield to Trevor on his judgment of Loehle's work, and have edited my response. Here's another thoughtful analysis of Loehle:

http://thatstrangeweather.blogspot.com/2007/11/loehle-reconstruction.html

Answer 5

You look at recorded history. If history says that it was warmer 1000 years ago in a period known as the Medieval warm Period (MWP) then there should be some indications of it in our history books.

My following information relies on the following web site:
http://www.archaeology.org/online/features/greenland/

The Viking colonized Greenland 1000 years ago. Archaeologists are now excavating through permafrost and finding settlements. What is more the Vikings refused to adapt the Inuit form of survival, instead relying European way of survival, mainly farming. So the temperatures had to be warm enough to farm. The tree ring data does not support such a version of history, saying it was colder than it is today.

What is more is that history goes on to show the onset of the little ice age. From the web site:
"An ice core drilled from the island's massive icecap between 1992 and 1993 shows a decided cooling off in the Western Settlement during the mid-fourteenth century."

"Over the decades the drop in temperature seems to have had an effect on the design of the Greenlanders' houses. Originally conceived as single-roomed structures, like the great hall at Brattahlid, they were divided into smaller spaces for warmth, and then into warrens of interconnected chambers, with the cows kept close by so the owners might benefit from the animals' body heat."

People who believe in the tree ring data, deny such events occurred or say it was a localized event. There have been temperature reconstruction studies from all over the world that say otherwise. In the following articles after the author states his disgust as to the reliance of tree ring data, he then goes on to give reference to scientific journals that shows the MWP was not localized and was a world wide phenomena.
http://www.john-daly.com/hockey/hockey.htm

Answer 6

The fact we are still calculating and assuming temperatures is of great concern to solid science. One factor changes the entire climate equation.

Meteorologists and climate scientists have been taught and believe that the earth absorbs the sun's rays. The importance of the information is critical because weather results because of the interaction of 3 things, water vapor, air and temperature.

Weather and climate are the interaction of temperature differences over land and water. Unfortunately due to lack of sight of temperature, absorption of solar radiation was assumed.

Why do we protect our skin from UV? It is a fast moving wavelength that excites and generates heat. Buildings and development are supposed to be finished with reflective materials as opposed to absorbent. UV is causing buildings and development to generate extreme heat, in some cases close to boiling temperature.

Go to http://www.thermoguy.com/globalwarming-heatgain.html and see actual pictures of temperature that are accurate to +-2%.

Good question

Answer 7

It's simple you do not accept the UN report because it comes from the UN. They have already been caught cherry picking flawed data to support their conjecture about climate predictions, why should they ever be trusted again?, is the question.

Answer 8

Data is skewed to support the agenda of the entity using it.

Answer 9

Hats off to Trevor!!

Answer 10

I trust these. Because they appear plausible and because they cite their sources.