When giving an example of an exponentially growing production curve, I used to cite cement production. Look at the data up to 2013: a beautiful growing curve with a doubling time of — very roughly — 10 years. Then, if we assume that the current concrete covered area in the world is about 2% (an average of the data by Schneider et al., 2009 and the Global Rural-Urban Mapping Project, 2004) then we would get to Trantor — bowling ball planet — in some 50 years.
Of course that wasn’t possible, but it was still a surprise to discover how abrupt the change has been: here are the most recent data (the value for 2018 is still an estimate from cemnet.com)
Impressive, right? Steve Rocco, smart as usual, had already noticed this trend in 2017, but now it is clearer. It looks like a peak, it has the shape of a peak, it gives the impression of a peak. Most likely it is a peak — actually, it could be the start of an irreversible decline in the global cement production.
Now, what caused the decline? If you look at the disaggregated data, it is clear that the slowdown was mainly created by China, but not just by China. Several countries in the world are going down in terms of cement production — in Italy, the decline started in 2010.
My impression — that I share with the one proposed by Rocco — is that this is not a blip in the curve, nor a special case among the various mineral commodities produced nowadays. It is a symptom of a general problem:
