A favorite shortcut employed by many in trying to decide between hypotheses is to enlist Occam’s Razor–that the simplest explanation for something is most probably right. Now this has strength because humans are pretty good at rationalizing notions they put forward, adding in new ingredients to keep a favored explanation from collapse. But a theory that has probably passed its must-use-by date will have enough extra bells and whistles to discourage Rube Goldberg from trying to get it to work.
However, there is nothing that says Mother Nature had to be supremely parsimonious. In a complex system like Earth, there can be odd coincidences that are meaningless (like the Moon and Sun sharing the same apparent diameter from Earth’s surface) and outcomes that might be highly improbable (taking over 500 million years to get intelligence after making complex animals with hard parts seems like dawdling, especially when burning most of that time on dinosaurs). Even so, Occam can be a help if used with care.
But lots of times you can face competing hypotheses that lack Occam-style clues. For instance, which is simpler: that post-5 Ma erosion of the High Plains of the U.S. was caused by an eastward tilt, or that this was the product of a changing climate? Both are pretty easy to describe; both have issues. Yet many earth scientists feel pretty comfortable arguing that one is correct; what is the basis of such assurance?
Arguably the most common discriminator used by earth scientists is the principle of least astonishment. What surprises you least feels, in an Occam kind of way, like the interpretation that is most likely. The problem is, we all are astonished differently.
If you are a sedimentologist, you might look at the problem of the High Plains as one of depositing the Ogallala Group in the Miocene as crucial. Could you possibly deposit something like that on a slope like that we have today? This seems so astonishing that if can’t be right; the original slope had to be lower.
But maybe you are a geophysicist looking at the ways to create a tilt about 5 million years ago over something like 1000 km. That looks really hard to do, especially if dynamic topography from flow under the lithosphere is ruled out. It would be astonishing if that happened; it must be that the grade was already there much longer ago.
Skepticism from both geoscientists is warranted; either of these seems really hard to do. Data is gathered by both sets of experts. Margaret McMillan and colleagues measure paleogradients in the Ogallala using a widely applied approach and find there must have been a lot of tilting. Will Levandowski and colleagues (including GG) look at geophysical measurements and find support for the elevations comes from within the crust, where changes over the past 5 million years seem exceptionally implausible.
Could these be resolved? Well, you could posit that prior to 5 Ma there was dynamic subsidence holding the western end down and once that was released, the crustal buoyancy expressed itself. But now Occam detectors are flashing red–this feels ad hoc. Of course, there could be mistakes in the measurements of paleogradient, or in relating seismic wavespeeds to densities–each side has poison darts to shoot at the other side.
What makes this frustrating is what makes this interesting. After all, in the end somebody will be astonished–the earth did something they didn’t expect.
And a funny thing, shoes flip feet in the Sierra, where those studying the sediments argue for no tilting despite deposition at an even steeper grade than modern-day Ogallala, while geophysicists feel they have good evidence for a very recent change in the buoyancy structure of the region.
Are you astonished yet?
Imagine, if you will, that a Congressional committee on transportation decides to have a hearing focusing on improving our transportation infrastructure. The session opens with the committee’s chair noting that there is considerable controversy in the engineering community on the use of steel beams in building overpasses, and so we should refrain from building overpasses until the community agrees on the need for steel beams. A highway engineer then testifies that no, there is no such controversy; at most, there are some disagreements on some details about anchoring beams and such not, and regardless of the choices made, new overpasses with steel beams are far better than the overpasses we continue to use today. A committee member then pipes up suggesting that overpasses are collapsing because of the weight of birds’ nests in the nooks and crannies on the overpasses. Nothing is done and roads continue to crumble.
You’d wonder just when Congressmen became such experts in engineering and marvel at their ability to keep anything from being done. And yet hardly anybody bats an eyelash these days when this scenario plays out with the House Committee on Science, Space and Technology’s hearing on “Using technology to address climate change” , where committee chair Lamar Smith added to his already considerable collection of misrepresentations of the science by claiming that humanity’s role in climate change is unknown and that there is “legitimate concern” that climate scientists are cooking their studies to get desired results (as opposed to, say, certain politicians misstating the science to get desired outcomes). Perhaps best of all was the suggestion from Alabama Congressman Mo Brooks, who offered that rocks falling into the ocean could be driving rising sea level.
Well, to be fair, Brooks actually asked about all the material being dumped into the oceans from rivers and such not, which at least isn’t unscientific. But these questions are often posed as though nobody had thought of that (the answer is that of the >3 mm/yr rise we see today, perhaps 0.02 mm/yr is from sedimentation). No doubt we’ll soon get pop quizzes from Congressmen about plate tectonics, glacial rebound (which is a player, but actually dropping sea level at about 0.3 mm/yr), the rise in sea level from more and more boats, etc. Yes, the people whose careers are spent worrying about this stuff have indeed thought about this stuff. We’re still waiting for the day when a Congressman’s question reveals a truth about science previously overlooked by scientists.
What was more disingenuous was Smith’s display of plots of fossil fuel use and sea level rise over time and saying that obviously the rates were so different that a connection was unlikely. (Phillip Duffy’s response kind of missed the point). Um, OK, time for a science experiment at home. Take a pot of water, put it on a gas burner. Turn on the burner–what is the rate of use of fuel? Pretty high right away, no? How about the temperature of the water? Um, still pretty cold, no? If you plotted them up, you’d probably find that while the rate of gas usage might be constant, the temperature of the water in the pot gradually increased. Obviously these are unrelated since they look different. (And the real world version involves 2 more levels of integration–first as CO2 levels increase, which is an integral of the fossil fuel use rate, then the change in heat in the atmosphere and oceans, which has both some integration and lag time, and finally the connection of that to sea level rise similarly has a lag and integration of sorts as thermal expansion is aided by melting ice. Yes, the curves will look different).
There are precisely two explanations for the kinds of misrepresentation engaged in by several members of Congress. Either they are stupid or they are crooked. GG actually doubts stupid; getting elected and managing a staff and doing all the fund raising and everything else requires some basic level of competence. This leaves crooked, and by that GG means that they need a certain result for reasons not being shared with the public and so seek to obfuscate. No doubt all or nearly all politicians make public pronouncements they know to be false as a means of appealing to their constituents, but one has to wonder at this point who this charade is for when significant majorities of Americans think the government is doing too little to deal with climate change.
Few if any scientists are wild about the modern funding environment. With the exception of some big planetary probes, where the shear cost of the probe ensures some long term funding, nearly all science is funded on a 1 to 3 year timescale. Competition can be fierce and news of getting funded is often accompanied by a request to reduce the budget some amount.
GG reminds you who read this that this was not the sort of environment originally envisioned for NSF.
Even as this environment might not nurture an Einstein or Newton, one could argue that it rapidly prunes away uninteresting science. Such a view would not find comfort in the last paragraph of a perspective in Science on new research into the response of C3 versus C4 plants in a higher CO2 world (research that appears to challenge if not overturn the assumption that C3 plants will do far better than C4 plants):
Reich et al. were only able to make their discoveries because their experiment ran uninterrupted for two decades. This is extremely rare globally, showing that funding for long-term global-change experiments is a necessity. The experiment relied on a concerted effort to continually apply for funding, given the largely short-term nature of funding cycles. Because most funding agencies place a value on innovation and novelty, scientists are forced to come up with new reasons and new measurements to keep existing experiments running. The tenacity of Reich et al. and their ability to keep their experiment running has overturned existing theory and should lead to changes in how we think about and prepare for Earth’s future. Who knows how many processes remain undiscovered because of the unwillingness of funding agencies to support long-term experiments?
Frankly, similar long term programs in very diverse fields have been terminated for similar reasons, including solid earth science, so this isn’t just biology or climate change. For instance, the USGS has pulled a large number of stream gauges over the years in the western U.S. under the logic that we had seen enough to know what we needed to know–an absolute travesty given both long-term climatic oscillations, the reality that rainfall in arid and semi-arid areas is highly erratic, and the real possibility that a long term set of observations would be crucial in better understanding impacts of global warming on the hydrologic cycle. And that is for an agency that has monitoring as part of its mission; individual scientific projects are even harder to keep going. It would seem we really need a program for taking the long view–something few in politics ever do.
It is impressive within a few hours to see different facets of the current administration’s desire to sideline science within what we should now call the Environment Plundering Agency. On one front, there is effectively an implementation of the gruesomely misleading HONEST act that Lamar Smith pushed awhile back under the guise of “sound science.” Basically this will throw away a huge amount of peer-reviewed science on the environmental and health impacts of various pollutants. That the EPA really wanted to bury this news is that their own press release was just a pointer to a Daily Caller interview with administrator Pruitt, a result that led the National Association of Science Writers to write a letter complaining about the failure to respond to questions and the use of partisan publication for the sole source for policy information. All this as the agency claims it is pursuing “transparency” (which, it would seem, they take to mean something you don’t ever see).
While this is the most pernicious move, at the same time the EPA is engaging in false equivalence in their latest talking points guidelines, which try to say that we don’t really know how much human activity contributes to global warming.
It bears repeating that pursuing ignorance as government policy is profoundly stupid, and amplifying it is inappropriate.
Although in some ways overexploitation of water resources has faded out a bit as climate change has caught the focus of those worried about the sustainability of civilization, it hasn’t gone away. Water managers in the western U.S. have probably paid closer attention to the possible changes in climate than…well, nearly everybody. And unlike many others, they are looking to act. But how?
The California drought that ended in early 2017 was a preview of all the problems climate change is apt to generate. While the snowpack and rainfall amounts were not as low as in the late 1970s drought, the heat was noticeably greater, and research found that the intensity of the drought on vegetation was greater than the older, drier drought because of the higher amounts of evaporation and transpiration. And then the drought ended in dramatic fashion, with big snowpacks and rainfalls leading to the erosion of the spillway of the Oroville Dam in late winter of 2017. Basically feast or famine.
So what is the rational response to this? Frankly, it is to have more water storage, ideally with less evaporation. And, somewhat oddly, increasingly variable precipitation puts pressure on the usual alternative of improved water conservation.
GG has pointed out here and in The Mountains that Remade America that the Sawyer decision that ended hydraulic mining in most of the Sierra Nevada is a very interesting precedent when you consider global warming and oil and gas companies. We’re getting closer to seeing if the comparison will withstand real scrutiny, as the City of New York has filed suit (joining a number of smaller jurisdictions, including Boulder) against the five largest oil companies. As with the plaintiff in Woodruff v. North Bloomfield, the New York City case alleges material damages, and as in the older case, this was a consequence of the action of several companies. And as in that case, the only way to mitigate damage would be to leave large economic reserves of a mineral (as legally defined) in the ground. Arguably the 1884 decision recognized that the damage to a growing economic sector (agriculture) outweighed damage to a stagnant sector (gold mining). We’ll see if any judge in the U.S. wants to walk in Judge Sawyer’s footsteps….