Tony Heller Against the Globe

Another post in which Tony Heller (aka Steve Goddard) explains how researchers would be wrong, if only they used his own blinkered worldview. His post Climate Science – The Fact and Data Free Science , (archive), attacks a paper from April 2016, Emergence of heat extremes attributable to anthropogenic influences . Or rather he quotes an extract from a Climate Central article on the paper, Scientists Trace Climate-Heat Link Back to 1930s .

The paper's behind a paywall, but from the abstract and the Climate Change article it seems they modeled the likelihood that any given record breaking global temperature year would have been a record without human influence. They conclude that whilst it's almost certain that most of the records set after 1980 would not have been set without increasing CO₂, there is also a good probability, greater than 50%, that the records from 1937 through the 40s, would not have been set without human influence. As the abstract says:

We find a significant human contribution to the probability of record-breaking global temperature events as early as the 1930s. Since then, all the last 16 record-breaking hot years globally had an anthropogenic contribution to their probability of occurrence.

Emergence of heat extremes attributable to anthropogenic influences

Scientists Trace Climate-Heat Link Back to 1930s

I not sure about the emphasis on record breaking years, and it is surprising that the relatively small CO₂ rise in the late 30s had a detectable effect on temperatures. I think it's clear that CO₂ was not the main reason for the high temperatures. But the paper is not claiming it was - just that it would have been less likely to get a record high temperature without the additional boost of CO₂.

Tony Heller, naturally, thinks the whole report is not just wrong but insists the authors hadn't looked at any data, and were unaware of what the CO₂ levels were in the 30s. Both claims that are obviously wrong. He then makes the claim there is no correlation between CO₂ and temperature.

Had these scientists actually looked at any data, they would have known that the heat of the 1930's peaked at 310 PPM CO2, and the heat has declined as CO2 increased. There is no correlation between CO2 and heatwaves.

There may be an attempt to move the goalposts here, by quietly shifting to talking about heatwaves, when the paper is only talking about temperatures. He's also failed to notice that temperatures did not peak in the 30s, but in the 40s. He illustrates his claim about the lack of a correlation between CO₂ and temperatures with this graph.

Source: Climate Science – The Fact and Data Free Science

To get this he's had to exclude most of the data. First he's limited the graph to just the US, when the report is clearly talking about global temperatures. This has the usual problem that temperatures were much warmer in the US during the 30s than they were in the globe as a whole.

Secondly, Heller limits the graph to just summer months. The US heat of the 30s were mostly associated with summer, later warming more with winter. NOAA's figures show annual US temperatures increasing at almost twice the rate as US summer temperatures.

Thirdly, he only looks at maximum temperatures, rather than average daily temperatures. NOAA's figures show minimum summer US temperatures increasing at twice the rate as maximum temperatures.

Finally, he uses his own naive calculations rather than relying on official data such as from NOAA. His calculations seem to just take an average of all stations, which has many potential problems. NOAA's own figures still show a slight rise over the entire period in US Summer Maximum temperatures, whilst Heller's figures show a slight decrease. This is what the graph looks like if you use NOAA's figures rather than Heller's.

Comparison of US Summer (June - August) Maximum temperatures with CO_{2 (ppm)}

In both cases the correlation is not statistically significant, but the one using NOAA data is positive - the one using Heller data is negative.

If we look at the data that actually matters as far as the research goes, global annual mean temperatures, the correlation with CO₂ is obvious and statistically significant.

Comparison of Annual Temperature Anomalies (in °C) with Atmospheric CO_{2 (ppm)}

Of course, this doesn't prove CO₂ is the cause of global warming - just that the correlation exists.

Tony Heller does this all the time. He makes his own crude calculations based on a limited selection of the available data, and then claims that any research that doesn't agree with his figures is not just wrong, but a lie.