Global Mean Temperature

[palerider]

Is there a global mean temperature upon which claims of AGW are based?

What is that temperature at present?

What was it 20 years ago?

 

[dogtowner]

is it the same as two years ago !
how can we know if its accrste ?

 

[steveox]

And Here it is,,he Media blames it on Global Warming

Well,, Wasnt my prediction was right when after the winter the news media was going blame global warming when summer comes? Am i wrong folks?

 

[palerider]

I am guessing that warmers don't want to answer for fear of exposing the fact that the disparity that exists between various "databases" on what the global mean is is multiple times larger than the amount of warming being claimed for the past 100 years.

 

[Lagboltz]

Is there a global mean temperature upon which claims of AGW are based?

What is that temperature at present?

What was it 20 years ago?

This gives the sources:
https://en.wikipedia.org/wiki/File:Instrumental_Temperature_Record.svg

 

[steveox]

What about this?

So who was responsible for Global Warming in 1000BC? Cars,Air Condtioners werent invented back then

 

[Lagboltz]

Ox, you are missing the point. It isn't what happened over the last millennia. It is well known that there were many swings in temperatures. The OP asked what is happening over the last two decades. That is the nature of the graph I posted.

 

[steveox]

Im not missing the point..Liberals claim man is the reason for global warming. Man is not to blame. Its the Sun. The Sun is getting hotter like Mars is also having global warming. If Mars is getting warmer then how can it be mans fault? were not even on Mars yet.

 

[Lagboltz]

You are still missing the point. I only showed a graph. Where did I say anything about blaming man?

 

[steveox]

You didnt but these damn liberals will do anything to twist the truth around. Like Al Gore for example

 

[palerider]

This gives the sources:
https://en.wikipedia.org/wiki/File:Instrumental_Temperature_Record.svg

Any idea what the margin of error is for that graph?

 

[Lagboltz]

Any idea what the margin of error is for that graph?

The graph is the average of several hundred points points throughout the world. The averaging of many points increases the accuracy by the square root of the number of measurements. This is an excerpt of the abstract of the research.

Uncertainty estimates in regional and global observed temperature changes: A new data set from 1850

A comprehensive set of uncertainty estimates has been derived to accompany the data: Estimates of measurement and sampling error, temperature bias effects, and the effect of limited observational coverage on large-scale averages have all been made. Since the mid twentieth century the uncertainties in global and hemispheric mean temperatures are small, and the temperature increase greatly exceeds its uncertainty. In earlier periods the uncertainties are larger, but the temperature increase over the twentieth century is still significantly larger than its uncertainty.

 

[palerider]

The graph is the average of several hundred points points throughout the world. The averaging of many points increases the accuracy by the square root of the number of measurements. This is an excerpt of the abstract of the research.

Now that's interesting. In your posts above, you were all over steveox for supposedly missing the point of the original post. I ask very specific questions.....do you have any idea of what the margin of error is for that graph? You apparently missed the point of the very specific question asked in the original post and my very specific follow up question. First, your graph didn't provide an answer to the original question, you provided a graph of temperature anomolies which is not the global mean temperature and secondly, there were two possible answers to my question: 1) Yes I do, it is X degrees or 2) No I don't.

So again, do you have any idea what the margin of error is for that graph which, by the way, didn't answer any of the questions in the original post.

 

[Lagboltz]

I'm sorry I misread what you wanted. From the graph and references, I thought you could figure it out from there. The error for each red point is about +/- .2 degrees C. For the 5 year moving average on the blue curve, the error would be about +/-.05.

To answer your OP, the surface temperature over a ten year average is 14.51 deg C for the 2000's. The ten year average for the 1980's is 14.18 deg C. (Goddard Institute for Space Studies) Errors for the later two measurements are about +/- .1 deg C. That translates to 58.12 deg F now and 57.52 in the 1980's. I know you asked for the temperature for the "present", but nobody could possibly know that.

A further note that has nothing to do with your OP is that surface temperature is not always a good measure for some analyses of global problems. In the long run, the air temperature in your refrigerator is less important than the temperature of the stuff inside. I don't know of any study of that includes the thermal capacity of the earth mantel, the heat of fusion of ice, thermal gradients in the ocean, etc.

 

[Lagboltz]

Oops, the errors I gave above are from the HadCRUT data set and are only one aspect of the error. The NASA data set is clearer, and the errors are +/- .5 C annually. (See http://data.giss.nasa.gov/gistemp/graphs_v3/)