I propose a basic classification system for human pauses that is based on how widespread (spatial extent), sustained, and pronounced (magnitude), reductions in human mobility are (Fig.1b). Importantly, I recommend that anthropause be reserved only for events of high scale at any time and on a global or continental scale. This definition states that the Black Death pandemic, early COVID-19 lockdowns, and the Chernobyl catastrophe caused anthropauses. This can be compared with other events using a schematic classification cube (Fig.1b). But first, let’s clarify a few points.
First, it is essential to ensure that terminology and processes are closely linked. Some authors use the term anthropause to describe positive environmental changes that are caused by lockdowns. While it is understandable to initially focus on the potential benefits, conflating cause (changes of human mobility) and effect(environmental responses), is not helpful when using the term scientifically. In fact, the original anthropause concept made no assumptions about the sign of conservation impacts and environmental responses.1 (Fig.1a). Evidence from the COVID-19 pandemic shows a wide range of lockdown effects.2,3.
Second, we must define human mobility. COVID-19 lockdowns resulted in notable reductions of pedestrian counts, road, water and aircraft traffic (and associated pollutant outputs), all of which could have had adverse environmental impacts.1,2,3,4. It is reasonable to consider changes across all dimensions of human mobility for modern human pauses. However, comparisons with preindustrial events must focus on the environmental presence and impact of humans. It is important to note that humans can disappear from an area if they move elsewhere, perish, or shelter there. Changes in human mobility can also be caused by natural and anthropogenic catastrophes and conflict.5. Although important research targets, the ultimate drivers and proximate factors that influence changes in human movement are not part Fig.1b. It is important to remember that many events will be associated in some way with human tragedy or suffering.1.
Third, operational definitions of the schemes spatiotemporal scalars are required. While human pauses can be ordered by their duration, they are more easily classified according to their spatial extent. This is both for practical and conceptual reasons.7. The categories presented here are pragmatic and cover four orders (Fig.1b). This will allow for meaningful comparison of environmental impacts caused different types of human pauses.
It is important to understand how the magnitudes of events should be measured. Human mobility has increased dramatically over the past century and will likely continue to increase in the future. Therefore, it is important to compare the magnitude of human pauses against baseline levels for the area and time period under consideration. This is not an absolute measure. The COVID-19 pandemic has shown that human mobility does not always drop to zero after an anthropause. There can also be significant spatio-temporal variation between response levels. Preliminary analyses show that approximately 57% were in partial or full lockdown at the start of April 2020.2There were noticeable local increases in mobility when governments allowed personal exercise1.
