25 Years of Monitoring Global Temperatures from Satellites and an Interview with Christy and Spencer of UAH

It’s been 25 years since Spencer and Christy of the University of Alabama at Huntsvillle published their 1990 paper Precise Monitoring of Global Temperature Trends from Satellites.  The abstract reads (my boldface):

Passive microwave radiometry from satellites provides more precise atmospheric temperature information than that obtained from the relatively sparse distribution of thermometers over the earth’s surface. Accurate global atmospheric temperature estimates are needed for detection of possible greenhouse warming, evaluation of computer models of climate change, and for understanding important factors in the climate system. Analysis of the first 10 years (1979 to 1988) of satellite measurements of lower atmospheric temperature changes reveals a monthly precision of 0.01°C, large temperature variability on time scales from weeks to several years, but no obvious trend for the 10-year period. The warmest years, in descending order, were 1987, 1988, 1983, and 1980. The years 1984, 1985, and 1986 were the coolest.

“…no obvious trend for the 10-year period”, probably didn’t go over too well.

Also see Roy Spencer’s post 25th Anniversary of Global Satellite Temperature Monitoring.  There, Roy introduces an interview by Paul Gattis, published at AL.com, titled 7 questions with John Christy and Roy Spencer: Climate change skeptics for 25 years.   The interview begins:

The silver anniversary of Roy Spencer’s career-defining moment arrived with no expectation in March. He didn’t realize it until someone mentioned it to him.

For John Christy, he had no idea that a discovery announced in 1990 would not only still resonate 25 years later but would be at the center of a raging debate.

The date was March 29, 1990. That was the day – though unbeknownst to either Christy or Spencer – they publicly became climate change skeptics.

The scientists at the University of Alabama in Huntsville are known throughout the environmental community as being skeptical that climate change (or global warming) will have a catastrophic effect on the earth. The crux of the matter is that their research, using satellite data to measure temperatures in the atmosphere, disagrees with climate models they say that overstates the earth’s warming.

The rest of the interview is here.  It’s worth a read.  The comments on the thread there contain the usual exchanges between skeptics and the CO2 obsessed.


The current UAH lower troposphere temperature data do show rising temperatures since 1979.  See Figure 1, which is from the February 2015 Global Surface (Land+Ocean) and Lower Troposphere Temperature Anomaly & Model-Data Difference Update.

Figure 1

Figure 1

But, with all of the updates and corrections to the UAH TLT data since 1990, do they still show little warming during the period of 1979 to 1988 as noted in the 1990 paper?  The answer is yes.  As shown in Figure 2, during that period, the UAH TLT data have a very low trend compared to the surface temperature datasets.

Figure 2

Figure 2

Thanks to John and Roy.  I’m looking forward to the corrections in the next version.


About Bob Tisdale

Research interest: the long-term aftereffects of El Niño and La Nina events on global sea surface temperature and ocean heat content. Author of the ebook Who Turned on the Heat? and regular contributor at WattsUpWithThat.
This entry was posted in Lower Troposphere Temperature. Bookmark the permalink.

2 Responses to 25 Years of Monitoring Global Temperatures from Satellites and an Interview with Christy and Spencer of UAH

  1. Pingback: 25 Years of Monitoring Global Temperatures from Satellites and an Interview with Christy and Spencer of UAH - Perot Report

  2. Thanks, Bob, for a good look at the data. Always appreciated.
    Christy and Spencer did a great thing with the existing satellite resources. Their continued works have been helping reestablish scientific climatology.

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