How is global temperature calculated?

Question

Specifically, what data has been used to show that the earth has been warming the last decade or so. What about the temperature data that has been used for pre 1970's?

Answer 1

Forget the b/s with computer models. With the recent cooling trend they are rendered useless.

I am also sick of hearing on how the economy is computer model predicted so climate modeling is right. WRONG: 80 %, the economy models are wrong. Greenspan just called out to the idiots that they should tweak their models for the uncertainty in the housing markets.

How about the computer model the US government Census Bureau spent millions of tax dollars on and it's only good for the scrap yard. Now they have to hire 600,000 part time workers to get the numbers right.

Give me a break!!!!

Answer 2

Regarding "How is global temperature calculated?"

It's simple.... if you use the Goresmatic Calculator, one can see that by examing Gore's bank accounts that the colder it gets, the lower his account balances are. The warmer it gets, the larger the balances in his accounts.

Answer 3

Since none of our resident AGW alarmists care to answer the question, I will.  They ignore the incomplete temperature record for most of the Earth from the 1800's through the mid-1900's.  How can you accurately calculate the global mean temperature when no one was taking accurate measurements over 75% of the Earth?  The answer is they couldn't.  Yet they claim they have proven man-made global warming.  

Read the attached article if you want an eye-opener regarding the calculation of the global mean temperature prior to accurate global temperature measurements.

Answer 4

The most reliable method is surface stations with a thermometer and proper methodologies for placement and monitoring. There are indeed thousands of such stations, the US has a large number placed around the country. In some cases the data they gather is influenced by their surroundings, such as placement too near a heat source or pavement, which soaks up sunlight and radiates that as heat. Walk barefoot on a road in the summer and you know the effect. Whether or not the readings from these stations is adequately adjusted for this effect is questionable. If you ignore the stations that have this effect, the Urban Heat Island, the global temp has not increased as much as reported. Looking at only rural surface stations also gives a lower overall reading.

As to the data collected prior to the 1970s, scientists armed with thermometers have been monitoring temp for a long time, just not in this organized fashion. There are far fewer monitoring stations in the oceans, which comprise the majority of the Earth's surface and contrary to media reports, the Earth is not warming universally, some areas are much cooler, some are much warmer. Overall, it hasn't yet topped the record set in 1998.

Answer 5

A variety of data sources is used, including land based stations, and satellites.  Independent research groups use slightly different data and methodology, they all get similar results.  Details here:

http://data.giss.nasa.gov/gistemp/2007/

discussed in detail, with confirmation, at:

http://tamino.wordpress.com/2008/01/24/g...

More about the methodology here:

Hansen, J., R. Ruedy, J. Glascoe, and Mki. Sato, 1999: GISS analysis of surface temperature change. J. Geophys. Res., 104, 30997-31022, doi:10.1029/1999JD900835.

The first website includes a graph with "error bars" representing the statistical uncertainty in the data.  Pre 1970 they're larger, of course, but the overall trends are still clear.

Before it comes up, I'll point out that numerous studies have shown the data is not contaminated by the urban heat island effect.  Examples:

David E. Parker (2006). "A demonstration that large-scale warming is not urban". Journal of Climate 19: 2882–2895.

T. C. Peterson (2003). "Assessment of Urban Versus Rural In Situ Surface Temperatures in the Contiguous United States: No Difference Found". Journal of Climate 16: 2941–2959

Also, reports of satellite data conflicting with surface data are old and incorrect.  It turns out the satellites sensors were mistakenly including information from the stratosphere, which is cooling.  That's another proof of CO2's role in global warming, the stratospheric cooling is due to CO2 intercepting heat.

Answer 6

There are thousands of temperature stations located all around the planet.  They've been measuring the global temperature with these stations since 1850.

Answer 7

Scientists use three closely connected methods to understand changes in Earth’s climate. They look at records of Earth’s past climates to see how and why climate changed in the past, they build computer models that allow them to see how the climate works, and they closely monitor Earth’s current vital signs with an array of instruments ranging from space-based satellites to deep sea thermometers.

Records of past climate change reveal the natural events—such as volcanic eruptions and solar activity—that influenced climate throughout Earth’s history. Today, scientists monitor those same natural events as well as human-released greenhouse gases and use computer models to determine how each influences Earth’s climate.

Answer 8

ask algor

Answer 9

If you really examine this detail you might find out they really have no clue about climate change because they ignore the geothermal flux warming the ocean. It is quite clear the ocean is being warmed a lot by geothermal heat and nothing is known at this time about how this effects the climate. So, if you dismiss as useless the entire geothermal flux you get the wrong answer whatever model you use.