How Our Understanding of Climate has Evolved over 100 years (or 110, depending how you count).
The 1922 Encyclopedia Britannica is a fascinating document. Or perhaps I’m just an incredibly boring person. Whatever the equation, it’s something I like to check now and then. If I may argue the case for the former, the 1922 Encyclopedia Britannica is in the public domain and is a one hundred year-old snapshot of human knowledge and thought. It’s marvelous. Although it also has some profoundly uncomfortable parts. Imperialism and casual racism abounds. In an encyclopedia. I mean, dude. By today’s standards, it’s appalling how causally and confidently racist a supposedly educational article can be. However, it was a product of its time and was an intellectual stepping-stone for anyone who could afford it. It does not have an entry on Climate Change. It does, however, have one on climate. The entry on Climate is remarkable:
““Climate” is the average condition of the atmosphere. “Weather” denotes a single occurrence, or event, in the series of conditions which make up climate. The climate of a place is thus in a sense its average weather. Climatology is the study or science of climates.” (Encyclopedia Britannica, 11th edition, 1911.)
Yes, I know it says 1911, not 1922. The definition didn’t change even as the new editions got cranked out. Whether you want to fuss about which is the proper date, by today’s standards, the above definition is incorrect. Climate is not static and the averages can shift depending on a multitude of complicated factors. Generally, we think of climate as has having 30-year averages rather than being fixed. On longer timescales, everything from the brightness of the sun (which varies a bit) to the eccentricates of the Earth’s orbit (which varies a bit) to volcanic activity and human-caused climate change. Yes, apologies, climate change is caused by humans. How, you may ask. Well, here is another telling moment from the definition of climatology in 1922:
“Climatology has to deal with the same groups of atmospheric conditions as those with which meteorology is concerned, viz. temperature (including radiation); moisture (including humidity, precipitation and cloudiness); wind (including storms)… and also, but of less importance, the composition and chemical, optical and electrical phenomena of the atmosphere” (Encyclopedia Britannica, 11th edition, 1911.)
What is fascinating about this part of the 1922 climate entry is that they do have all of the basics. Where they are wrong, however, is which elements of climate are the most important. The chemical phenomena of the atmosphere is one of the most critical parts of determining the climate of the Earth. Greenhouse gasses, chemical components that absorb radiation and heat the atmosphere, are the critical problem facing our climate, and changing how we release greenhouse gasses into the atmosphere is the key to preventing unmanageable climate change.
Isn’t it remarkable how much we’ve learned in 100 years? Fine, 110 years. Again, however you do the counting, we have seen a world of progress. Flawed and uneven progress, to be sure. But progress all the same. From thinking that the Earth’s climate was fixed and immovable by humanity, to realizing our climate and atmosphere have a delicate balance that we can upset without intending it or even realizing it in some cases. Progress may not be consistent, or even, but reading an encyclopedia from a hundred years ago makes me realize how much can change, and how extraordinary things might be in 2122.