WUWT readers may recall: Upside-Side Down Mann and the “peerreviewedliterature” at Climate Audit. Steve McIntyre wrote then:
“…there isn’t a shred of doubt that Mann et al 2008 used these proxies upside down from the Tiljander interpretation. “
It seems the use of “upside down data interpretation” has leaked into a White House official report. WUWT reader “Jimmy” says in Tips and Notes: Check out the interesting temperature graph on this economic post from the White House today, “Deviation from Normal Temperature”.
3. The first quarter of 2014 was marked by unusually severe winter weather, including record cold temperatures and snowstorms, which explains part of the difference in GDP growth relative to previous quarters. The left chart shows the quarterly deviation in heating degree days from its average for the same quarter over the previous five years. By this measure, the first quarter of 2014 was the third most unusually cold quarter over the last sixty years, behind only the first quarter of 1978 and the fourth quarter of 1976. In addition, there were four storms in the first quarter that rated on the Northeast Snowfall Impact Scale (NESIS). The right chart shows that no quarter going back to 1956 had more than three such storms.
Yes, while technically correct, showing heating degree days, it is upside down to the normal human interpretation of temperature, especially when the title says “Deviation from Normal Temperatures” while presenting degree days rather than a temperature plot. The other two largest positive spikes are the brutal winters of 1977 and 1978.
UPDATE: here is how I would have presented this graph. Simply changing the title removes the inverted thinking about “Deviation from Normal Temperatures” and leaves it technically correct without unnecessarily confusing the reader.
Most people looking at that graph don’t have a clue what a heating or cooling degree day is. In case you don’t, here is a definition from NOAA/NWS
Q: What are degree days?
Heating engineers who wanted a way to relate each day’s temperatures to the demand for fuel to heat buildings developed the concept of heating degree days.
To calculate the heating degree days for a particular day, find the day’s average temperature by adding the day’s high and low temperatures and dividing by two. If the number is above 65, there are no heating degree days that day. If the number is less than 65, subtract it from 65 to find the number of heating degree days.
For example, if the day’s high temperature is 60 and the low is 40, the average temperature is 50 degrees. 65 minus 50 is 15 heating degree days.
Cooling degree days are also based on the day’s average minus 65. They relate the day’s temperature to the energy demands of air conditioning. For example, if the day’s high is 90 and the day’s low is 70, the day’s average is 80. 80 minus 65 is 15 cooling degree days.
Heating and cooling degree days can be used to relate how much more or less you might spend on heating or air conditioning if you move from one part of the country to another. Of course you’d have to take into account how well insulated your new home will be in comparison to your old one and the different costs of electricity, gas or heating oil. You could also use records of past heating degree days to see if the money you’ve spent on insulation, or a newer furnace or air conditioner is paying off. To do this, you’d also need records of past energy use.
The heating degree season begins July 1st and the cooling degree day season begins January 1st.
But also of interest in the same report is this graph and summary, which does make sense. It seems the winter of 2013/2014 set a new record for snowstorms.
4. Within the first quarter, several key indicators were lower in January and/or February before rebounding strongly in March, suggesting that the severe weather had a disruptive effect that only began to abate at the end of the quarter. Light vehicle sales, average weekly hours, core retail and food service sales, and core capital goods shipments dipped starting in December and/or January before bouncing back in March, and so were left little changed for the quarter as a whole. One outside group has estimated that the elevated snowfall in the first quarter slowed the annual rate of GDP growth by 1.4 percentage points, with all of that lost activity to be made up in the second quarter.
With this severe winter behind us, I have to wonder if any similar WH economic report (or any U.S. government report) exists that shows anything close to “slowed the annual rate of GDP growth by 1.4 percentage points” for a warmer than normal period. The summer of 2010 would be a good candidate for such a report.
If readers know of one, leave a note in comments.