The book Limits to Growth was published in 1972¹ and caused uproar. It proposed that the earth was a finite resource and that digging stuff up could not continue for ever. Mined stock would become increasingly difficult to extract and prices would rise. The models included the possibility that minerals could actually run out, but in reality the rising prices would be likely to break the economy before that happened. The advice in the book was that economic growth should be curbed. In the furore that followed, the business world mounted a spirited defence of the status quo and little action was taken.

In 2015 Kristín Vala Ragnarsdóttir and Harald U Sverdrup published an update paper ² showing that the predictions in the original book were being validated by real data, that there really were such limits, and that, for many minerals those limits are already apparent. We can see some of these in action now: deep mining of coal has gone out of fashion, and manufacturing has moved to countries where cheaper, more accessible, coal can be had; oil reserves are becoming more focused in particular parts of the world and the USA, and to some extent, the UK, are looking at fracking to provide independence.

What we need to be aware of is that many of the minerals examined by Ragnarsdóttir and Sverdrup are likely to reach scarcity in mere decades, even allowing for recycling. Some of these minerals are essential for current technologies: batteries, computers, chemical processes. The high tech world we live in is going to become very expensive.

One face of it, running out of helium (9 years, apparently), or lithium (25 years) is not going to contribute to climate disruption, biodiversity loss or any of the other issues relating to planetary boundaries³. Mining more low-grade sources might well cause problems, but we might assume that any destruction would be localised. There are two issues that come out of this, though.

The first point is that running out of resources has a familiar feel to it. It seems to run in parallel with the global system disruptions that we started out with, and ultimately, all of these things boil down to economic growth. The more stuff we use, the more we need to dig up, and, since stuff has to be made and transported, the more stuff we use, the more we pollute. At first sight, the adaptations we need to make look much the same.

The second point, though, is that running out of minable minerals will severely limit our ability to build technology solutions, whether they be more wind farms or vertical city gardens. The limits need to be observed if any practical action is to be taken.