Are surface temperature records reliable?
What the science says...
Select a level... |
![]() |
![]() |
![]() | ||||
The warming trend is the same in rural and urban areas, measured by thermometers and satellites, and by natural thermometers. |
Climate Myth...
Temp record is unreliable
"We found [U.S. weather] stations located next to the exhaust fans of air conditioning units, surrounded by asphalt parking lots and roads, on blistering-hot rooftops, and near sidewalks and buildings that absorb and radiate heat. We found 68 stations located at wastewater treatment plants, where the process of waste digestion causes temperatures to be higher than in surrounding areas.
In fact, we found that 89 percent of the stations – nearly 9 of every 10 – fail to meet the National Weather Service’s own siting requirements that stations must be 30 meters (about 100 feet) or more away from an artificial heating or radiating/reflecting heat source." (Watts 2009)
Temperature data is essential for predicting the weather. So, the U.S. National Weather Service, and every other weather service around the world, wants temperatures to be measured as accurately as possible.
To understand climate change we also need to be sure we can trust historical measurements. A group called the International Surface Temperature Initiative is dedicated to making global land temperature data available in a transparent manner.
Surface temperature measurements are collected from about 30,000 stations around the world (Rennie et al. 2014). About 7000 of these have long, consistent monthly records (Fig. 1). As technology gets better, stations are updated with newer equipment. When equipment is updated or stations are moved, the new data is compared to the old record to be sure measurements are consistent over time.
Figure 1. Station locations with at least 1 month of data in the monthly Global Historical Climatology Network (GHCN-M). This set of 7280 stations are used in the global land surface databank. (Rennie et al. 2014)
In 2009 some people worried that weather stations placed in poor locations could make the temperature record unreliable. Scientists at the National Climatic Data Center took those critics seriously and did a careful study of the possible problem. Their article "On the reliability of the U.S. surface temperature record" (Menne et al. 2010) had a surprising conclusion. The temperatures from stations that critics claimed were "poorly sited" actually showed slightly cooler maximum daily temperatures compared to the average.
In 2010 Dr. Richard Muller criticized the "hockey stick" graph and decided to do his own temperature analysis. He organized a group called Berkeley Earth to do an independent study of the temperature record. They specifically wanted to answer the question is "the temperature rise on land improperly affected by the four key biases (station quality, homogenization, urban heat island, and station selection)?" Their conclusion was NO. None of those factors bias the temperature record. The Berkeley conclusions about the urban heat effect were nicely explained by Andy Skuce in an SkS post in 2011. Figure 2 shows that the U.S. network does not show differences between rural and urban sites.
Figure 2. Comparison of spatially gridded minimum temperatures for U.S. Historical Climatology Network (USHCN) data adjusted for time-of-day (TOB) only, and selected for rural or urban neighborhoods after homogenization to remove biases. (Hausfather et al. 2013)
Temperatures measured on land are only one part of understanding the climate. We track many indicators of climate change to get the big picture. All indicators point to the same conclusion: the global temperature is increasing.
------
See also
Understanding adjustments to temperature data, Zeke Hausfather
Explainer: How data adjustments affect global temperature records, Zeke Hausfather
Time-of-observation Bias, John Hartz
Check original data
All the Berkeley Earth data and analyses are available online at http://berkeleyearth.org/data/.
Plot your own temperature trends with Kevin's calculator.
Or plot the differences with rural, urban, or selected regions with another calculator by Kevin.
NASA GISS Surface Temperature Analysis (GISSTEMP) describes how NASA handles the urban heat effect and links to current data.
NOAA Global Historical Climate Network (GHCN) Daily. GHCN-Daily contains records from over 100,000 stations in 180 countries and territories.
Last updated on 15 August 2017 by Sarah. View Archives
[DB] "There was in fact no warming between 1950 and 1980"
More cherries for BP:
[Source]
Pay no attention to that man behind the curtain...
[DB] Curious, that the temperature records show an inexorable rise every single year, isn't it? ;)
Let us not focus on the few cherry-flavored flat or declining spots lest we miss that overall rising signal in the noisy background:
[Source]
[DB] "Accurate?"
Nope. Not in the least. The various datasets (not just GISS) have been checked & rechecked, both internally and independently. Even amateur "scientists" have replicated the global rise in temperatures using as little as 10% of the station data because there is a global warming signal in the data.
You are repeating memes long ago proven false. Care to share where you heard this and why you bring it up here (meaning SkS; this is definitely an appropriate thread)?
[DB] Do you mean this graphic:
You seem to frequent disinformation websites, where the focus is on conspiracy theories and not on the primary literature itself.
No wonder you take the position you do.
[DB] "Not that I find what you say not credible, but I like to check things for myself."
Then you would be the first skeptic to actually follow through and do the hard work. However, I suggest you start here, with additional resources available here and here.
Please be sure to report back your results to us.
[DB] As someone new to SkS, you probably don't know how to best take advantage of all the resources this site has to offer.
There is an immense amount of reference material discussed here and it can be a bit difficult at first to find an answer to your questions. That's why we recommend that Newcomers, Start Here and then learn The Big Picture.
I also recommend watching this video on why CO2 is the biggest climate control knob in Earth's history.
Further general questions can usually be be answered by first using the Search function in the upper left of every Skeptical Science page to see if there is already a post on it (odds are, there is). If you still have questions, use the Search function located in the upper left of every page here at Skeptical Science and post your question on the most pertinent thread.
Remember to frame your questions in compliance with the Comments Policy and lastly, to use the Preview function below the comment box to ensure that any html tags you're using work properly.
Participants who take the time to ensure a less incendiary tone will also find a great deal of positive and contributory dialogue with other, more knowledgeable participants here (some of whom are actual climate scientists).