Much public discourse in global warming centres around the oft-quoted rise in temperature of approximately 1.1°C in global average temperature in the post-industrial period. This is considered in some quarters to constitute a “Climate Emergency” demanding “Climate Action”. In this paper we first dissect the background behind this number and what it means. Second, we use the Epica-Vostok Ice core dataset, a single proxy dataset for temperature data sampled every century for the last 800,000 years or so and ask the question “Is a 1.1°C temperature rise in a century unusual in this dataset?”
The answer is surprising. By considering interglacial onsets and decays as well as intermediating Ice Ages, it turns out that a rise of this amount would have been considered unusual more than 200,000 years ago, but this rise is not unusual in the current interglacial which started some 20,000 years ago with around 16% of all centuries since the last Ice Age exhibiting a temperature rise of at least 1.1°C. None of these could have anthropogenic components as they pre-dated the industrial era. This result suggests that attempts to partition the current rise into anthropogenic and non-anthropogenic components are questionable given that it is not even unusual.