Climate-truthing in the Palmetto State

According to an article by Chelsea Harvey at Business Insider, "This Is The Climate Report South Carolina Spent Years Hiding."

It sounds ominous, and so I read the report, which left me feeling – unsurprisingly – that Business Insider had done a poor job of science journalism, and understanding why some appear to have resisted releasing the report.

Here is what Business Insider had to say about the report:

The document shows a history of rising temperatures, warming waters, and increases in severe weather events in the state, and also notes concerns for the future. The chart below shows how temperatures at the Greenville-Spartanburg airport have changed between 1895 and 2010.

There's a clear upward trend, especially from 1970 on.

The report actually analyzed four climate stations, as it notes:

To evaluate climate variability in South Carolina, a first-order analysis of the annual mean monthly USHCN [United States Historical Climate Network] temperature data was performed. Temperature data recorded at the Greenville-Spartanburg (GSP) Airport in Greer, University of South Carolina (USC) in Columbia, Beaufort and Georgetown were used to investigate trends in temperature variability. These stations were selected to represent the three major geographic divisions of South Carolina: mountains-piedmont, midlands-sandhills, and coastal plain.

And here are the four graphs the South Carolina Department of Natural Resources (DNR) report published:

Choosing just to publish the Greenville-Spartanburg airport graph in the upper left is convenient for alarmism, given how the data at Beaufort and Georgetown shows no sign of an overall warming trend since 1895, and the USC station shows temperatures back in the first half of the 20th century about equal to those seen over the past couple decades coupled to little – if any – overall warming.  Good science journalism either (1) shows all four graphs from the report, (2) chooses the most representative graph of the four, and/or (3) discusses in detail all the similarities and differences among the four graphs.  Business Insider chose none of these options, instead choosing to publish only the most alarmist, and non-representative, graph.

No wonder the public generally believes in climate hysteria: the mainstream media is giving them only the most alarmist pieces of the datasets.

Interpretational problems also exist in the DNR report.  The authors show the following figure and then make the associated claims:

Winter maximum temperatures demonstrated a slight warming trend for the period and conversely, minimum winter temperatures showed a very slight cooling trend.

Nope.  There is most certainly no warming trend in winter maximum temperatures over the past century, and the cooling trend is more than very slight since the early 1900s.  But note the language the DNR report used: "slight warming trend" to describe no warming trend, and "very slight cooling trend" to describe a substantial cooling trend.  Entirely backwards.

Thus, when the report states in the Executive Summary that "South Carolina climatological trend data, 1895-2010, has been analyzed and shows a warming trend that started during the 1970s continuing to the present," it is not accurately describing the data.  NOAA's National Climatic Data Center has the state's average annual temperature since 1895, and there is no significant trend since 1895, nor is there a significant trend over the last three decades.  These climate realism facts should have been explicitly provided to readers in the Executive Summary.

Later in the report it is claimed that "temperature and precipitation data provide a record of variations in South Carolina climate extending back into the late 1800s. Air-temperature data from 1970 to the present show a steady increase in mean annual temperatures."  Steady increase?  If there is no significant trend since 1984, how can the increase be steady?  It is not.  Looking at the state's historical temperature patterns, it is clear that temperatures have plateaued over the last 15 years, much as they did during the 1920s and 1930s.

This more general quote from the DNR report about climate change in the southeast is also problematic:

Current climate models predict continued warming across the southeast, with the greatest temperature increases projected in summer. Annual average temperatures are projected to rise 4.5 F by the 2080s under a lower emissions scenario and 9 F under a higher emissions scenario with a 10.5 F increase in summer.

There has been no significant trend in annual average temperatures for the southeast climate region since records began in 1895, or during the last 30 years.  Add to that the fact that during the past 15 years, the correlation is toward cooling – not warming.  We are also still waiting for the complete 2014 climate record in the southeast, but based on the January to November data available so far, one would expect this recent lack of statistical significance and a correlation towards cooling to be continued.  This last 30 years of data makes predictions of up to 9º F warming in the southeast by the 2080s seem far-fetched.  Perhaps the DNR report should have mentioned the warming hiatus in South Carolina and, more broadly, the southeast?

The same lack of statistical significance exists for trends in the southeast's summertime temperatures.  No sign whatsoever of any significant trends since 1895 or during the last 30 years.  The last 15 years – as with the annual temperature – have a negative correlation toward cooling.  Once again, these details – which should make us cautious about alarmist climate modeling projections – should have been discussed at length in the DNR report.

Stepping back and looking at the DNR report and associated climate data objectively, maybe there was a good reason this climate report should have stayed hidden.