One of the emptiest slogans littering the climate change debate is “it’s basic physics,” which puts doubters on a par with those who dispute the times table, periodic table or a round Earth. In our video tackling the "Simple Physics slogan", Professor William van Wijngaarden observed that no one really knows how clouds will respond to greenhouse warming. So what’s behind climate models’ confident projections of how the weather will change? It’s simple, all right: they guess. Specifically, a recent study in the journal Atmospheric Research notes, cloud physics operates on microscopic scales while climate models’ smallest “chunks” are hundreds of kilometers wide. So instead of using real equations describing clouds and precipitation, modelers invent approximations called “parameterizations” that can’t be checked, and jury-rig today’s data in ways that may not work tomorrow. Does it matter? Only if getting reliable answers does.

The Atmospheric Research authors write: “Blind tuning until the model yields a ‘reasonable’ output, or tuning a single parameter or process may ‘remove the symptom but not the cause’… Understanding the extent of the simplifications in the parameterization is also relevant for atmospheric research because it may result in the model being in reasonable agreement with observations but unphysical, or right for the wrong reasons because of compensating errors.”

It’s not a small problem. Climate model projections rather than actual observations lie at the heart of climate alarmism and hence of climate policy. The incredibly costly experiments we are now living with (high electricity prices, landlocked oil, attempts to stop 3^rd world electrification, to name but a few) result from world leaders being shown scary projections from climate models which, no matter how much they fail to match reality over the intervals where forecasts and observations are both available, are said to be unchallengeable because they’re built on “basic physics.” Except they aren’t. They are based on tuning and approximating, licking and pasting, hocus and pocus, hoping some of it is somewhat valid and pay no attention to that man behind the curtain.

Articles like this one in Atmospheric Research sound like bombshells. But in fact they only state things well known among the experts, namely that the physics underlying key climate processes, like cloud formation and precipitation, is at best only partially understood and cannot be derived from first principles in ways that can then be applied by climate models for many reasons including, when it comes to clouds, the issue of scale.

The modelers use approximations not because they are lazy or ignorant; they do it because it’s the only way to create models at all given the magnitude of the scientific problem. But they should be honest with us about what they’re doing, why, and its limitations. Instead, lest they should fuel skepticism, they cover the duct tape and baling wire with a shiny coat of PR about “basic physics”.

In truth there nothing “basic” about any of this. Here, as in so many other places, the empty slogan conceals a reality that is the exact opposite of the popular line.