The Science is Settled

Last week in major cities across the country, the Left marched in large numbers in support of science. On its face that's a very good thing, but when those same people argue that any discussion of climate change is moot because "the science is settled", their advocacy for the scientific method breaks down rather badly. Anyone who has any knowledge of science understands that science is never "settled." We learn more, we improve understanding, we create better analytical and empirical methods, and sometimes, conventional wisdom is jettisoned as a result.

Jeremy Samuel Faust summarizes the marches nicely when he writes:

... Little of what I observed [at the marches] dissuades me from my baseline belief that, even among the sanctimonious elite who want to own science (and pwn anyone who questions it), most people have no idea how science actually works. The scientific method itself is already under constant attack from within the scientific community itself and is ceaselessly undermined by its so-called supporters, including during marches like those on Saturday. In the long run, such demonstrations will do little to resolve the myriad problems science faces and instead could continue to undermine our efforts to use science accurately and productively.

Using science "accurately and productively" demands that one never utter the phrase, "the science is settled." A case in point:

Bradley Fikes reports on the results of a major medical study:

In another blow against decades of accepted medical wisdom, one of the most prestigious, long-running studies reports that lowering sodium intake doesn’t reduce blood pressure.

The study also implies that most Americans are consuming a perfectly healthy amount of salt, the main source of sodium. But those who are salt-sensitive, about 20 to 25 percent of the population, still need to restrict salt intake.

Consuming less than 2,500 milligrams of sodium daily is actually associated with higher blood pressure, according to the Framingham Offspring Study report, given today. The American Heart Association recommends consuming no more than 2,300 milligrams of sodium daily, equal to a teaspoon of ordinary iodized table salt.

High blood pressure is a known risk factor for heart disease and stroke. Hence, lowering salt intake is supposed to lower blood pressure and thus reduce the risk of cardiovascular disease and stroke. But the study found that supposition to be unfounded.

Moreover, the lowest blood pressure was recorded by those who consumed 4,000 milligrams or more a day — amounts considered dangerously high by medical authorities such as the American Heart Association.

But ... but ... but ... science said that salt was bad for you and many believed that the science was settled, right?

An assessment of the effects of salt on blood pressure is orders of magnitude (I suspect that many of the marchers have no idea what that phrase means) less complex than the effects of dozens of parameters and their quantitiative impact on global climate. If blood pressure's affects were not settled science, I think it's reasonable to assert that the underlying drivers of climate change are also not settled science. To state otherwise is a profound display of ignorance, even if the statement is made by a "scientist."