Climate Actually Changes! Film at 11:00!

Guest Post by Willis Eschenbach

Last month (April 2010), the US Environmental Protection Agency (EPA) put out a study called “Climate Change Indicators in the United States” (13 Mb PDF). I read through it … depressingly bad science.

To start with, they parrot the findings of the IPCC as their “evidence” that everything we see in the climate record is human-caused. They say:

The buildup of green- house gases in the atmosphere is very likely the cause of most of the recent observed increase in average temperatures, and contributes to other climate changes. (IPCC 2007)

Despite the “very likely” certainty of the IPCC, I see the current level of our knowledge of the Earth’s climate a bit differently, as shown in Figure 1:

Figure 1. Graph showing our understanding of the climate. Image is the painting by J. M. W. Turner, “Rain, Steam and Speed – The Great Western Railway”.

Having asserted that all changes are due to humans, they then list a bunch of changes, and consider their case as being established. Here’s how they put it:

The indicators in this report present clear evidence that the composition of the atmosphere is being altered as a result of human activities and that the climate is changing. They also illustrate a number of effects on society and ecosystems related to these changes.

Now, that particular statement is very carefully crafted. It is very painstakingly  worded so that no one can say that they claimed the changes in climate are caused by the changes in the “composition of the atmosphere” … but heck, if you mistakenly were to assume that, the EPA won’t get in your way.

In other words, CO2 is rising and climate is changing … stunning news.

But that’s just the start. The individual parts of the report are marked by plain old bad science.

Here’s one example among many. This is the record of “heat waves”, which they define as follows:

While there is no universal definition of a heat wave, this indicator defines a heat wave as a four-day period with an average temperature that would only be expected to occur once every 10 years, based on the historical record.

This indicator reviews trends in the U.S. Annual Heat Wave Index between 1895 and 2008. This index tracks the frequency of heat waves across the lower 48 states, but not the intensity of these episodes. The index uses daily maximum temperature data from the National Oceanic and Atmospheric Administration, which keeps records from weather stations throughout the nation. Approximately 300 to 400 stations reported data from 1895 to 1910; over the last 100 years, the number of stations has risen to 700 or more.

The index value for a given year could mean several different things. For example, an index value of 0.2 in any given year could mean that 20 percent of the recording stations experienced one heat wave; 10 percent of stations experienced two heat waves; or some other combination of stations and episodes resulted in this value.

Sadly, although they say they use NOAA data, they don’t say where the data that they used is located. Well, no, actually that’s not quite true. They say:

The data for this indicator are based on measurements from the National Oceanic and Atmospheric Administration’s National Weather Service Cooperative Observer Network. These weather station data are available online at: www.nws.noaa.gov/os/coop/what-is-coop.html.

Unfortunately, when you go to that URL, there’s no data. There’s just a description of the Cooperative Station Program entitled “What is the Coop Program?” … but I digress …

Regarding heat waves, they say:

The frequency of heat waves in the United States decreased in the 1960s and 1970s, but has risen steadily since then. The percentage of the United States experiencing heat waves has also increased. The most severe heat waves in U.S. history remain those that occurred during the “Dust Bowl” in the 1930s, although average temperatures have increased since then.

Having said that, Figure 2 shows their data for the Heat Wave Index, the linear trend over the entire period, and the change in atmospheric CO2 during the period.

Figure 2. “Heat Wave Index” (yellow line) and CO2 level (red line, right scale). Orange line is the linear trend for the entire period.

You’d think that the only reasonable conclusions from this chart would be that heat waves and CO2 are not related in the slightest, that there is no overall change in the US Heat Wave Index, and that there appears to have been a step change in the data in 1980 … but this being the EPA, you’d be wrong. This is all part of the ‘CO2 is rising and climate is changing’ mantra.

And you would also think that they would give us drought information to go with this. For example, I showed the change (or rather the lack of change) in the Palmer Drought Severity Index from 1895 to 2009 in my post “Come Rain or Come Shine“.

But strangely, rather than report that drought is no more common now than a hundred years ago, they say:

During the 20th century, many indices were created to measure drought severity by looking at trends in precipitation, soil moisture, stream flow, vegetation health, and other variables. This indicator is based on the U.S. Drought Monitor, which integrates several of these indices.

Why is the U.S. Drought Monitor a strange choice for their analysis? Well, because that particular drought indicator only contains data that goes all the way back to … 2000. Not even one decade of data. And of course, their conclusion is:

Because data from the U.S. Drought Monitor are only available for the most recent decade, there is no clear long-term trend in this indicator.

Well, duh … the USHCN maintains several long-term drought indicators which cover the period 1895 – present, so the EPA chose to only report on an indicator with a nine-year record, and then explains that the record is too short to show a trend.

I could give you many more examples, but my stomach won’t take it. This is the US EPA, however, so I suppose I shouldn’t be surprised. My tax dollars at work …