By Dr. Robert Thorson

I may be one of the few people left on Planet Earth who shudders slightly whenever they hear the phrase “global warming.” Its mention triggers a flood of inconvenient thoughts that must be allowed to subside before I can proceed with logical thinking. Paraphrasing Elizabeth Barrett Browning:

How do I misunderstand thee?

Let me count the ways.

My threefold path to misunderstanding involves technical inaccuracies, value judgments and freighted connotations. Technically, a globe is a geometric shape, describing any round or spherical object. It’s hard to warm or cool a shape. In less precise usage, a globe is a scale model of a planet, moon or star. Which globe in “global warming” are we referring to?

If we’re talking about El Sol, we’re talking sense because the sun’s globe has been heating up for 6 billion years. If we’re talking about the Earth’s globe, then we’re talking nonsense because our planet has been cooling down ever since its fiery birth and baptism by glowing lava during the Hadean Eon. Only a tiny fraction of the planet — its lower atmosphere (troposphere) and the uppermost part of the liquid ocean and solid crust — have alternately warmed and cooled.

In terms of value judgments, some like it hot. Opossums like warmth because their habitat range is limited by cold. Penguins like cold because their range is limited by warmth. The same applies to extinct species, with dinosaurs giving thumbs-up to heat and woolly mammoths thumbing down (OK, they don’t really have thumbs).

Some tourists like it hot as well, preferring the glaring earth tones of the American desert to the shade-dappled world of the deciduous forest. A chronically chilled resident from a rural place with sufficient water would probably look forward to global warming.

The connotation of the phrase “global warming” is often more potent than its denotation, especially in the popular media. Warming has become shorthand for the meteorological and hydrological consequences now unfolding as ecological and social ones. Politically, global warming connotes one more plank in a left- leaning worldwide environmentalist platform, right up there with biodiversity and the less sexy plague of synthetic agricultural pesticides.

My most recent concern about global warming is the false connotation that joining the scientific consensus is simply the fashionable thing to do. The majority of scientists (including myself) joined the consensus — that warming is a grave concern, is partly anthropogenic and that reductions in emissions are needed — because the weight of evidence tipped them in that direction. Cats may hang out together, but they never herd or flock. Scientists are like that too.

Fuzzy thinking about climate change today involves the notions that global warming from fossil fuel emissions is a fairly new idea, that it’s a bad thing and that its validity derives from consensus. These ideas are turned on their heads by the example of Svante Arrhenius, the Nobel prize-winning Swedish genius who invented the concept of anthropogenic global warming more than a century ago.

After a successful career as a physical chemist, he flew solo scientifically with an article in 1896 and a book in 1908 identifying and explaining the CO[subscript 2] greenhouse effect. He quantitatively explained the dramatic oscillations between glacial and interglacial periods, and pointed out that burning fossils fuels would forestall the next ice age, clearly a good thing. For the next half-century, his ideas were tossed out in favor of the consensus view that astronomical changes caused the ice ages. We now know that such orbital influences are solar toggle switches for Earth-based climate feedbacks caused largely by greenhouse gasses and glaciological factors.

Svante’s story illustrates: that global warming is an oversimplified misnomer; that concerns about it are value judgments; that it’s century-old grist for the modern mill; and that consensus thinking can be good and bad.

So how do I really feel about the phrase “global warming?” I think it’s fine, provided you mean a long-term, statistically significant, net increase in the average temperature of the planetary troposphere. Otherwise, think of me as a global warming skeptic — a literary one.

Remember. The globe isn’t warming. The troposphere is. So is the politico-sphere.