The National Oceanic and Atmospheric Administration (NOAA) claimed that this past June was the warmest ever in its temperature records, which go back to 1880. The global average temperature in June was 61.1 degrees, or 1.22 degrees Fahrenheit above the 20th century average of 59.9 degrees. At face value, this appears to be consistent with the theory that global warming is caused by mankind’s use of fossil fuels. But face value can be deceiving, and the value is not what it appears to be.
In fact, the claim that June 2010 was the warmest on record has no value at all.
NOAA gets its temperature data from the Goddard Institute for Space Studies. They calculate the average temperature of the Earth using data from land-based thermometers and ocean buoy and ship measurements of water temperature. However, there is a major problem with how GISS measures temperature in a very large region — the Arctic.
The problem is that they don’t have any thermometers there. So they make it up. No, really!
Despite this lack of arctic temperature data, GISS shows that this June the area north of eighty degrees latitude was up to four degrees warmer than the long-term average. You must be asking: how can GISS show any temperature readings at all north of eighty degrees if they don’t have any data? Really, I’m not kidding — they make it up.
GISS uses measured temperature data from lower latitudes and then extrapolates them to the Arctic. Using this method, any readings warmer than average in the lower latitudes are pushed into the Arctic by a smoothing technique. GISS uses a 1,200 kilometer smoothing for its data, meaning that the temperature reading for one thermometer is used as the temperature for a 1,200 kilometer box in all directions from that location. Where there are more thermometers, the boxes overlap, and the readings of one thermometer are averaged with others around them. This reduces the effect of each individual thermometer.
But in data-sparse regions, the value of one thermometer takes on a much greater value.
In the case of the Arctic that one thermometer and the few that are on the fringe of the Arctic are used to calculate the average temperature of everything north of eighty degrees. When one uses a 250-degree smoothing factor for the data from GISS, the truth is suddenly and shockingly revealed: they don’t have any thermometers north of eighty degrees and very few north of sixty degrees. The 1,200 kilometer smoothing floods the Arctic with assumed temperature readings that don’t actually exist.
But it’s just one region that’s always terribly cold. That couldn’t have driven the June averages much higher, right?
Dr. James Hansen is the director of GISS. He has stated: (See correction below.)
The 12-month running mean global temperature in the GISS analysis has reached a new record in 2010. The main factor is our estimated temperature change for the Arctic region.
Without the very warm Arctic temperatures, June 2010 is nowhere near the warmest ever.
The evidence comes right from the source, with Dr. Hansen’s statement. But news outlets generally don’t know this, and assume that claims coming from NOAA must be true. In broadcasting there is an old saying: “Why let the truth stand in the way of a good story?”
We at PJM try very hard to ensure the accuracy of pieces we publish. When we want back and looked for a citation for the quote from Dr Hansen, it appears to have been misquoted; Dr Hansen’s original summary reads as follows:
(1) insight into why the GISS analysis yields 2005 as the warmest calendar year, while the HadCRUT analysis has 1998 as the warmest year. The main factor is our inclusion of estimated temperature change for the Arctic region. We note that SST change cannot be used as a measure of surface air temperature change in regions of sea ice, and that surface air temperature change is the quantity of interest both for its practical importance to humans and for comparison with the results that are usually reported in global climate model studies.
(2) 12-month (and n×12-month) running mean temperatures provide more information than the usual graphs with calendar-year mean temperature. The 12-month running mean fully removes the annual cycle, which exists even in temperature anomaly time series. The magnitude and duration of global temperature effects of volcanoes and the Southern Oscillation can be seen much more clearly in a 12-month running mean graph such as Figure 10.
(3) the 12-month running mean global temperature in the GISS analysis has reached a new record in 2010. The new record temperature in 2010 is particularly meaningful because it occurs when the recent minimum of solar irradiance (Frohlich, 2006; data at http://www.pmodwrc.ch/pmod.php?topic=tsi/composite/SolarConstant) is having its maximum cooling effect. At the time of this writing (May 2010) the tropical Pacific Ocean has changed from El Nino conditions to ENSO-neutral and is likely headed into the cool La Nina phase of the Southern Oscillation. The 12-month running mean global temperature (Figure 9b) may continue to rise for a few more months before the ENSO change causes the next decline. It is likely that global temperature for calendar year 2010 will exceed the 2005 record, but that is not certain if a deep La Nina develops quickly.
(Emphasis indicates the sentences that were included in the quotation.)
While the conclusion that GISS data adjustments account for a large part of the warming indicated still seem warranted, this misquotation clearly implies something Dr Hansen did not say. PJM apologizes to Dr Hansen and to our readers for the error.