Sunday, June 11, 2017

The Hockey Stick and Breitbart

There are few things that will get anti-science climate change deniers in a froth more quickly than bringing up the hockey stick. Maybe it’s because the hockey stick shows, without question, that global warming is real. The graph even leads to the conclusion, with no other data necessary, that it’s caused by humans.

For a review, the hockey stick is a nickname given to a graph produced my Dr.s Michael Mann, Raymond Bradley, and Malcolm Hughes (NorthernHemisphere Temperatures During the Past Millennium: Inferences, Uncertainties, and Limitations)

The nickname is a result of the shape of the graph showing average global temperatures for the last several centuries. There was a gradual downward trend following the end of the Medieval Warm Period (MWP) in the 14th century until a very large upturn in the late-19th century. Here is the original graph:

Source: Mann, Bradley and Hughes, 1999
As you can see, there is no comparable uptick in temperature anywhere else in the graph and this change occurred as our industrial complexes were expanding, strongly indicating this uptick was caused by us. Of course, further research was needed to confirm this result. That research has been done and the hockey stick has been confirmed by multiple studies.

Source: Mann, et al, 2008

Interestingly, this paper has been scrubbed from the NOAA website. The science haters in charge of the government are trying, and failing, to hide the science.

You can read a good discussion concerning the hockey stick here.

With confirmation of the hockey stick comes confirmation of the conclusion. Yes, the science is settled – manmade emissions are causing global warming and the associated climate change.

So, it isn’t surprising to find deniers go into a tizzy every time someone mentions the hockey stick and to produce any number of arguments to try and discredit it. The latest was an article in the Notrickzone: Scientists Increasingly Discarding ‘Hockey Stick’ Temperature Graphs

[UPDATE: For an excellent review of how completely false the Notrickzone article is go here. I particularly like the summary:
We rank the claims made by both Breitbart and No Tricks Zone as false, because they dramatically misrepresent the findings of the scientists who conducted the research and utilize poorly-articulated straw man arguments to further misrepresent the significance of the work of those scientists. These studies were local in nature, narrow in scope, meant to address how the climate system functioned in the past, and pose no threat to the tenets of anthropogenic climate change.
Thanks to jmac for providing the link.]
It doesn’t take long to see what the problem is with this article, namely cherry picking. Cherry picking is selecting data to support your predetermined conclusion and ignoring data that doesn’t. Take a quick look at the article and you’ll see graphs for the western Mediterranean, the Spanish Pyrenees, northern Spain, Arctic summer temperatures, South China Sea, Alberta, Scotland, and more. In other words, the author of this piece went and found scientific papers that discussed some aspect of temperature for some given region and he then expanded it to mean global warming.

There’s two huge problems with this. The first is that we are discussing ‘global’ warming, not ‘Alberta’ warming. There’s the cherry picking. Given global warming, it is a fact of the laws of thermodynamics that some areas will actually see a cooling trend. As more heat is stored in the atmosphere, more work will be done. Weather can only occur when there is a temperature difference between regions. So, as more work is done in the form of weather, it is required that some areas be warmer than others. That is why we focus on global averages. We want to know what is happening to the entire planet. What is happening in the Spanish Pyrenees is important and is a worthwhile thing to study, but it doesn’t fall under the definition of ‘global’ warming.

The other problem is that some of these graphs, showing temperature trends for limited regions instead of global averages, still show the hockey stick is present, even for the isolated region in question. The author of this article is trying to prove the hockey stick isn’t real by showing examples of it actually existing. And, I’m sure he has no problem with that logic.

I’m not the only one to find this article doesn’t pass any kind of scientific muster. You can read a much better review, conducted by five scientists, here.

I also refer you to this comment that was submitted:

This is just another giant cherry pick by "nottickszone" of the earths average annual air temperature. These cherry picks are typical of "notrickszone" and other denier blogs. Nobody has said that every region of the earth will warm at the same rate.
“Global warming” means Earth's average annual air temperature is rising, but not necessarily in every single location during all seasons across the globe.

"Temperature trends across the entire globe aren’t uniform because of the diverse geography on our planet—oceans versus continents, lowlands versus mountains, forests versus deserts versus ice sheets—as well as natural climate variability. When you’re zoomed in on a particular place, you may not be able to see the overall trend.

It is only when scientists calculate the average of temperature changes from every place on Earth over the course of a year to produce a single number, and then look at how that number has changed over time that a very clear, global warming trend emerges. In other words, it’s only when we “zoom out” to the planet-wide scale that the trend is obvious: despite a few, rare areas experiencing an overall cooling trend, the vast majority of places across the globe are warming.
Observed trend in temperature from 1900 to 2012; yellow to red indicates warming, while shades of blue indicate cooling. Gray indicates areas for which there are no data. There are substantial regional variations in trends across the planet, though the overall trend is warming. Map from FAQ appendix of the 2014 National Climate Assessment. Originally provided by NOAA NCDC.

The reason a “zoomed out” view makes the long-term trend so clear is that Earth's annual average temperatures from year to year are found to be very stable when nothing is forcing it to change. Today, though, every decade since 1960 has been warmer than the last, and the last three decades each have been the warmest on record. Relative to geologic time, the warming that has occurred—1.5°F (0.85°C) over a span of 100 years—is an unusually large temperature change in a relati vely short span of time.

However, not all land masses and oceans have experienced or will experience a constant, identical rate of warming. Natural variations in our climate system cause temperatures to vary from region to region and from time to time, leaving sporadic fingerprints in the long-term temperature record. When you consider the global map above, you can see that in a few parts of the world temperature trends were basically ”flat” over the last century."

In conclusion, I have to wonder why this guy would write an article that is so easily debunked. I guess there are people who will believe anything that affirms their hatred of science, but why would you be willing to make such a fool of yourself in the process? But, then again, I guess that's what they specialize in at Breitbart.

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