Alexander the Great Explains The Drop In Extinctions

Guest Post by Willis Eschenbach

In a recent post here on WattsUpWithThat called The Thirteen Worst Graphs In The World, Geoff Chambers explores the graphs in a new book called “10 Billion”, by Stephen Emmott. The book appears to be Emmott’s first entry in the “Future Failed Serial Doomcaster” competition. I thought I’d take a look at one graph, the graph of extinctions. I know a bit about this subject, with both a detailed blog post called “Where Are The Corpses” and a journal article co-authored with Dr. Craig Loehle on the subject. Figure 1 shows Emmott’s graph in all its primordial glory.

Figure 1. Unlucky number 13 of the “13 Worst Graphs” of Stephen Emmott. SOURCE  The citation says “13. Adapted from S. Pimm and P. Raven, Biodiversity: Extinction by numbers, Nature, 403 (2000); A. barnosky [sic] et al. Has the Earth’s sixth mass extinction already arrived?, Nature, 471 (2011).  

I’ve located non-paywalled copies of the Pimm and Barnosky papers. I’m sure the alert reader can see a few problems with Figure 1 at first glance, including chartsmanship of the highest order. The things that caught my eye were the use of the logarithmic vertical scale; the lack of units on the vertical scale; the short level section followed by the abrupt jump around 53,000 years BC; the huge increase at the end; and oh, yeah, see the little hash marks ” // ” along the bottom time scale to the right of -50,0000?

As is my practice, I digitized this. Took about five minutes, because on a simple uncluttered graph you can use the automated features of the digitizing software. But before I discuss that, let me make some general comments.

Now, you recall I pointed out the hash marks in the time scale in Figure 1? Usually, that just means they’ve left out a chunk of years, it’s a common and legitimate technique used to show two separate time periods on the same graph. But they usually don’t splice the graph lines for the two periods together as he has done.

In addition, in this case the hash marks don’t mean just that. In this case, it also signifies a change in the time scale itself. So on the left side of the hash marks, the graph shows a span of about ten thousand years. On the right side of the hash marks, on the other hand, it shows a span of only about two hundred and fifteen years(1835-2050). Bizarre. The consequences of this are displayed and discussed later.

Next, regarding units, the extinction rates are usually given in units of extinctions per million species per year, or E/MSY. This makes comparisons awkward because we don’t know how many species there are. We can reduce the inexactness somewhat by noting that the Red List shows 207 extinctions of birds and mammals over the last 500 years. And in total, they list 15,565 species of birds and mammals. That gives us a raw rate of about 25 extinctions per million species per year (E/MSY). And that’s roughly the number that they give for the recent part of the data. So it seems that they are using the standard units, E/MSY.

The problem, as always, is in the interpretation of the data. As usual, humans are to blame, and I say that in all seriousness … just not the way the alarmists claim. For example, I’ve shown that the coral atoll damage ascribed to rising sea levels from human CO2 is actually due to human interference with the reef. Humans were the cause, but not from CO2.

And I’ve shown that the damage ascribed to human-caused warming in the Alaskan “climate refugee” village of Shishmaref is actually a combination of poor site selection (it’s on a barrier island), erosion due to poorly designed shoreline reinforcements, and human-habitation-and-road caused permafrost melting. Again humans are the cause … and again, from something other than CO2.

In the case of extinctions, once again humans are indeed the cause … but again, not through the mechanism they claim, that of habitat reduction. Instead, humans have caused widespread extinctions through the introduction of “alien predators” into new areas which had never before seen them. These alien predators were and are a wide variety of species, humans among them. The list includes dogs, cats, rats, rabbits, foxes, mongoose, gray squirrels, brown tree snakes, and a host of other species including funguses and diseases. Heck, in a wonderfully strange case of environmental recursion, it turns out that for a while the lovely Central American frogs were being helped to extinction by the fungus unknowingly spread by the very biologists studying their extinction … introduced predators.

And those introduced predators have wreaked untold damage, including but not limited to both species extinctions and local extirpations of the native species in Australia and the islands around the planet. The changes are not limited to the extinctions because, for example, when you introduce foxes to an Arctic island, the entire ecosystem changes, all the way down to the very plants covering the landscape.

But there’s an oddity in that kind of extinctions, those caused by introduced alien predators. It is reported, perhaps apocryphally, that when Alexander the Great saw the extent of his domain he wept because there were no new worlds left to conquer. And the same is true regarding extinctions from introduced predators. Most of those extinctions occurred in several waves. First there were early extinctions in the Caribbean in the 1500s. Then extinctions rose again during the first wave of expansion and exploration in the 1700s, and then again during the age of empires after 1850. Since peaking at the start of the 20th century, they’ve generally declined. Here’s the data from my earlier post .

Figure 2. Bird and mammal extinctions. Note that the units (extinctions per year) are different from the units in Figure 1 (E/MSY). ORIGINAL CAPTION: Stacked graph of the historical extinction rates for birds (grey) and mammals (black). 17 year Gaussian average of the data from Red List (birds) and CREO (mammals). Note the peak rate of 1.6 bird and mammal extinctions per year, and the most recent rate of 0.2 extinctions per year.

But in 2013, as with Alexander, there are few new worlds left for alien predators to conquer—there’s not much of the planet that hasn’t already seen invasive alien predators of many kinds. There’s no Terra Incognita that hasn’t been visited by the European or other explorers. And as a result, the worst of the extinctions from introduced predators are behind us.

Now, if we leave out the extinctions by introduced predators, then out of the 207 bird and mammal extinctions there are only 9 extinctions in 500 years, three mammals and six birds. This means that other than extinctions from introduced predators the extinction rate is only 1.2 extinctions per MSY … very low.

So with that in mind, here is the underlying data from Emmott’s graph in the normal form, showing both the early and late data.

Figure 3. Emmott’s data from his 13th graph, in the normal form, but still with a logarithmic scale.

Pretty hilarious, huh? When the Emmott data is put into its normal form we see the lunacy of the graph that he has spliced together and present. There is some data from 60,000 to 50,000 BC, then a huge gap in the middle followed by a few more years of data at the end. In order to understand it, let me divide it into the ice age record, and the modern and predicted record, and show each one separately.

Figure 3. Ice age extinctions, from 60,000 BCE to 49,500 BCE. This shows the normal presentation without the logarithmic scale

Now that, I have to call hokey. It has a huge jump between 53000 and 52000 years BCE, and while I imagine that it is supposed to reflect the so-called “Late Quaternary Extinctions” of the megafauna, I’ve never seen it represented like that. Nor do I have any idea why it would jump up and not come back down again … and I can’t find any such jump in the two works he cites, Pimm and Barnosky.

Moving on to the modern era and the future, here’s that chart. Since I don’t know what extinctions he’s talking about, I fear I can’t give the proper background of extinct animals. In Figure 4, you can see that the man is truly barking mad:

Figure 4. Modern and future extinctions, as Emmott would have us believe. Note what happens when we use the normal scale instead of the logarithmic scale.

Here’s the looney part. From 1835 up until the present (2013), the extinction rate is claimed to increase slowly from 16 E/MSY at the start to 28 E/MSY in 2013. Over the next 30 years, to 2043, this slow increase is supposed to continue at the same rate, with the 2043 value estimated at 37 extinctions per million species per year. Then, in seven short years, by 2050 it’s supposed to increase more than a hundred fold, to 4,600 in 2050. Does he really believe this pseudoscience?

First off, there’s no indication that the extinction rate has been rising steadily since 1835 as he claims. Compare his claims in Figure 1, to Figure 2 for what the data actually shows about the historical waxing and waning of extinctions over the years.

More to the point, my goodness, what’s supposed to happen in 2043 to drive extinction rates up by a factor of more than a hundred, two full orders of magnitude, up from 37 extinctions to 4,600 extinctions per MSY? A nuclear winter? A meteor strike? Runaway gene-spliced chimeras? The world wonders …

Finally, some of these numbers are supposed to be “after” Barnosky et al. That paper says:

The maximum observed rates since a thousand years ago (E/MSY ≈ 24 in 1,000-year bins to E/MSY ≈ 693 in 1-year bins) are clearly far above the average fossil rate (about E/MSY ≈ 1.8), and even above those of the widely recognized late-Pleistocene megafaunal diversity crash.

However, recall from above that other than extinctions from introduced species, which will never again reach the high values of the past, the current rate of extinctions is only about 1.2 extinctions per million species years … not different from the fossil extinction rates.

So in summary, Emmott took three different datasets. One was a bogus dataset regarding the middle of the last ice age. The second was a bogus estimate of modern extinction rates. The third was a colossally ridiculous estimate of the future changes in extinction rates. He spliced them all together and voila! The famous extinction hockeystick is born, the 13th unlucky bastard step-child of one Stephen Emmott.

Sometimes, these guys are beyond parody.

w.

Spreadsheet containing the digitized data and graphs is here.

PS—Yes, I know there are many other factors to consider in figuring historical extinction rates, it’s in the journal article. These are rough, raw, “order-of-magnitude” estimates. However, when everything is considered, the modern extinction rates (absent introduced predators) is not statistically any different from the historical rates. In other words …

The claimed “Sixth Wave of Extinctions” is a total fabrication.

Extinction rates are little changed from fossil rates, except for the historical wave of introduced predator extinctions, which are now safely in the past since there are no more empires left for Alexander the Alien Predator to conquer.

PPS—There’s a good discussion of the Emmott graphs over at Donna Laframboise’s excellent blog NoFrakkingConsensus. Geoff Chambers has much more information on Emmott at his blog. And at ClimateResistance there’s a very readable fisking of the individual claims.

PPPS—For an example of the “Sixth Wave of Extinctions” pseudoscience coming from a major environmental NGO, see the WWF … sad.