As I mentioned earlier, some denier comments were submitted to the post about Extreme Denial. This blog isn’t about spreading denier claims, it’s about exposing them, so their comments will get exactly the focus they deserve.
First up was “Owen Suppes,” who said:
What is a climate denier. Most deniers I encounter agree the world is warming as well carbons radiative forcing contributes to a warming trend. But where we deniers differ from the CAGW crowd; context. The writer offers us a picture displaying a modern warming, when the pictures takes in a longer view we discover two similar warming events within the same century. The dramatic picture once contextualized looses it’s flare. CAGW is tenuous hypothesis at best, losing ground to empirical evidence.
First things first: Mr. Suppes is changing the subject. The post was about how deniers so often pick an extreme as their starting point and leave out the context of what came before so they can misrepresent the underlying trend.
It’s worth emphasizing one of the key methods for spotting denier bullshit: that when it’s exposed, what they most want to do is change the subject.
He also implies that I left out the early 20th century to conceal a “similar warming event.” The reason I started with 1950 is that in the model for exogenous factors I quantified the el Niño effect using the Multivariate el Niño Index (MEI), and those data start at 1950. The MEI has been extended further back, but the “standard” MEI doesn’t predate 1950, so that’s when I started.
Mr. Suppes tried to pull the wool over your eyes with his talk of a “similar warming event.” Let’s take a look (some of the “context” he claims deniers are famous for when their specialty is being out of context). Here’s NASA temperature data since 1880, which certainly includes the century he flaunts:
We can reduce the noise, and we don’t even have to model exogenous factors (like el Niño, volcanic eruptions, and solar variations) to do so, all we have to do is smooth the data — reducing the noise influence is what that does. I’ll use two methods: a lowess smooth, and a piecewise-linear model based on changepoint analysis. Together they’ll show what we can actually know with confidence about what the trend has been doing, and they look like this:
Let’s focus on the trend, by plotting just the smooths:
Notice that I’ve labelled the two warming “events” since 1900, which Mr. Suppes claims are “similar.” How similar are they?
The first, using the piece-wise linear fit, goes from a low of -0.348°C up to +0.012°C, for a net rise of 0.36°C, while according to the lowess smooth ranges from a low of -0.344°C up to +0.011°C for a net rise of 0.355°C. The second, according to the piecewise-linear fit goes from -0.046°C to +0.806°C for a net increase of 0.852°C, according to the lowess smooth from -0.049°C to 0.826°C for a net increase of 0.875°C.
Not only has the second episode shown a net increase 236% or 246% bigger than the first, it has also lasted longer, at least 45 years, some 60% longer. No, sir, they are not “similar” in the sense you imply, despite both being warming episodes.
Perhaps Mr. Suppes thinks he’s surprising us with his claim. He’s not; we’ve heard it before many, many times (that’s the way zombie arguments are). The only “surprise” is that he and so many of his fellow deniers expect us to believe that a previous warming event, one which is less that half as big as the ongoing one (the one that’s not done yet), somehow makes climate science wrong.
True irony about the whole thing is that Mr. Suppes responds to a post which is, among other things, about deniers leaving out context (when they claim “no global warming for XX years), by claiming that his fellow deniers are paragons of context.
Before we go, a special note to commenters “ETW” and “co2isnotevil”: don’t worry guys — your turn is coming.
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