xkcd – The Word Sustainable is Unsustainable – http://xkcd.com

Transcript

Y axis: Frequency of the use of the word “sustainable” in US English text, as a percentage of all words, by year. Source: Google ngrams
2036: “sustainable” occurs an average of once per page
2061: “sustainable” occurs an average of once per sentence
2019: all sentences are just the word “sustainable” repeated over and over.

Vocabulary

frequency (n) /ˈfriːkwənsi/ the number of times something happens
sustainable (adj.) /səˈsteɪnəbl/ 1. able to continue over a period of time. 2. causing little or no damage to the environment and therefore able to continue for a long time
Google ngrams (n. phrase) a tool that allows you to see the frequency of certain words over the years. Try it out here.
occur (v.) /əˈkɜːr/ (formal) to exist or be present in a particular place or group of people (or, to happen, to take place)

Over the last few years, more and more people use the word “sustainable.” The initial use of the term was connected to the idea of protecting the environment: if something is sustainable, humans can keep doing it without damaging nature. However, more and more people started to use this word even though their actions or behavior was not environmentally sustainable… They still considered it was ok to use the word arguing that the definition is not only limited to the environmental definition.

Words start appearing at a certain point in time and also die out sometimes. When you learn English, it’s important to know when words are “archaic” (which means that the word is not used any more in today’s English). When you are not sure, you can check a dictionary, but you can also look it up in Google ngram to have more information.