Climate and the Media: II

The Incredible Shrinking Horse

The title of the story was "Watch out: Mammals shrink when Earth heats up, study says." The story reported evidence that, at a period when global temperatures were high, a number of ancient mammals became smaller, by fourteen percent in one case, by four percent in another.

There were two things wrong with the story. The first was the repeated use of the term "shrinking." What it was describing was evolutionary change over a period of several million years. The wording made it sound as though animals were actually shrinking and that is how I would expect a casual reader without much scientific background to read it. How else would you interpret

At least twice before in Earth's history, when carbon dioxide levels soared and temperatures spiked, mammals shriveled a bit in size.

The second was the picture that accompanied the story. It shows a modern horse, a Morgan, contrasted with Sifrhippus sandrae. The visual impression is of enormous shrinkage, the modern horse being nearly a hundred times the weight of the ancestral horse. But the change was happening many millions of years before there were any modern horses

My conjecture is that the article was designed to scare casual readers about the effects of global warming, to make them imagine that it would shrink them by a similar amount. It is possible that I am mistaken, that the author did not care about politics and was merely trying to write a story people would read. Shrinking from the size of a horse to the size of a cat is a much more dramatic story than evolutionary change of an ancestral horse from the size of a large cat to the size of a medium cat, which is what the article on which the story was based was describing.

Ocean Acidification

The pH of water is a measure of how basic or acidic it is. Pure water is neutral, has a pH of 7, meaning that it has an equal number of H+ and OH- ions, produced by the disassociation of water molecules: H₂O → OH- + H+. Water with more OH- than H+ is basic, pH>7, water with more H+ is acidic, pH<7. Sea water is basic, with a pH of about 8.1, down from about 8.2 two hundred years ago. It is getting gradually less basic by having CO₂ molecules dissolved in it.

Referring to the process as acidification is technically correct but misleading, since lowering the pH of ocean water presently at pH 8.1 moves it towards neutral; only past 7 does it become acidic. At the present rate of decline, that would take almost seven hundred years. Strong acids are dangerous, so “acidification” sounds scary. Neutralization does not sound scary. That is a good reason to call pH reduction acidification if you want to scare people. Lowering the pH of the ocean might cause problems but the reason is that oceanic organisms are adapted to their current environment not that it makes ocean water corrosive.

As evidence of the rhetorical use of “acidification” …

Parts of the Pacific, for instance, are already so acidic that sea snails' shells begin dissolving as soon as they're born. Meet the tiny, translucent "sea butterfly," whose home is currently being transformed into an acid bath.” (Vice, May 1, 2014)

It may well be true that pteropods function less well when their environment becomes less basic but it is not because they are now in an acid bath.

And here is another from the same source, still using “acidify” for its misleading implication but adding some false factual claims.

The Last Time Oceans Got This Acidic This Fast, 96% of Marine Life Went Extinct

(Vice, 4/9/2015)

Compare the headline to the first line of the story.

The greatest extinction event in the history of the planet was driven by oceans acidifying about as fast as they are today.

There is a difference between “got this acidic” and “acidifying about as fast.” CO₂ release during the Permian-Triassic extinction, which is the event the story is talking about, was at a rate comparable to current CO₂ release but it went on for about ten thousand years, as did the resulting reduction in ocean pH (“acidification”) described in the article that the story links to. The total amount of CO₂ released was about a hundred times the amount we can be expected to release over the next century or so,¹  much more than would be released by burning all known fossil fuels.²

Both the title of the story and the first line are false, but in opposite directions. The article linked to estimates the change in pH as .6-.7 over about 10,000 years, or about .0006-7 per decade. The IPCC estimates current pH change as about .016/decade, more than ten times as fast but, so far, for a much shorter time. The article does not give a figure for pH, only for change in pH, so does not say whether the ocean was “this acidic,” but the total change it estimates is six to seven times the decrease in pH over the past two centuries.

Climate Nuts vs the IPCC

In one climate thread online³ some years ago I was informed, by three different people, that global warming would:

Create two billion climate refugees

Flood most of the world's large cities

Destroy civilization.

The simplest rebuttal to such claims was the latest IPCC report, which at the time was the fifth. The IPCC, which had been doing its best to persuade people to support action to slow global warming, was unlikely to minimize the problem. But if you looked not at the rhetoric but at the factual claims the impending climate catastrophe looked like a wet firecracker.

The same evidence can be used against nuts on the other end of the spectrum, such as the gentleman in one thread who claimed that the IPCC had a budget in excess of twelve billion dollars. Pointing out to him that the actual budget, available on the web, came to about eleven million dollars had no effect. If, as he confidently believed, the IPCC is a massive fraud, inventing global warming out of thin air for its own sinister purposes, why should we be so naive as to believe their account of their budget? Pointing to webbed data on global temperature, which had increased by about one degree C since 1910, would be no more effective since he can, and probably would, claim that the data are fake. 

What he could not explain away so easily was the modesty of the IPCC's claims. If they are trying to scare people into doing something about global warming and if, as he believes, they are unconstrained by actual evidence and science, why don't they tell a better story? Two degrees of warming over the next 86 years, a foot or two of sea level rise, are not very impressive threats, despite all the rhetorical efforts of the IPCC and its supporters. Why don't they make it ten degrees and ten feet? Twenty feet? A hundred feet? Why don't they tell something closer to the story that their supporters want to believe?

If Life Gives You Peaches

The graph shows that while global temperature is currently rising, it is still well below what it was for most of the past two hundred and fifty million years and would have to rise by another 13°C to get back to the peak level of about sixty million years ago. 

The headline of the news story I found it in:

A 500-million-year survey of Earth's climate reveals dire warning for humanity

If life gives you peaches, make cyanide from the pits.

1. Dan Rothman of the department of Earth, Atmospheric and Planetary Sciences (EAPS) at MIT said:

“The rate of injection of CO₂ into the late Permian system is probably similar to the anthropogenic rate of injection of CO₂ now. It’s just that it went on for 10,000 years.” (Earthsky, November 25, 2011)

“An acidification event of ~10,000 years is consistent with the modeled time scale required to replenish the ocean with alkalinity, as carbonate deposition is reduced and weathering is increased under higher Pco₂ and global temperatures.” (Clarkson et. al., Ocean acidification and the Permo-Triassic mass extinction,” Science vol. 348, 10 Apr 2015, pp. 229-232. This is the article linked to in the news story.)

2. Dan Rothman, who calculated the average rate at which carbon dioxide entered the oceans and atmosphere at the time, finding it to be somewhat less than today’s influx due to fossil fuel emissions, said the total amount of CO2 pumped into Earth’s atmosphere over this time period was so immense that it’s not immediately clear where it all came from. He said: “It’s just not easy to imagine. Even if you put all the world’s known coal deposits on top of a volcano, you still wouldn’t come close. So something unusual was going on.” (Earthsky November 25, 2011)

“Specifically, the required model perturbation of 24,000 PgC exceeds the ~5000 PgC of conventional fossil fuels and is at the upper end of the range of estimates of unconventional fossil fuels (such as methane hydrates). We show that such a rapid and large release of carbon is critical to causing the combined synchronous decrease in both pH and saturation state that defines an ocean acidification event.” (Clarkson et. al., op. cit.)

3. On Google+, probably in 2014.