I propose a basic classification scheme for human pauses based on how widespread (spatial extent), sustained (duration) and pronounced (magnitude) reductions in human mobility are (Fig. 1b). Importantly, I recommend that the label anthropause be reserved for events of high magnitude at continental to global scale (and of any duration; Fig. 1b, Supplementary Note 1). According to this definition, the Black Death pandemic and early COVID-19 lockdowns caused anthropauses, while the Chernobyl disaster was followed by a regional human pause. A schematic classification cube can be used to compare these and other events (Fig. 1b); but first, a few points need clarifying.
First, it is crucial to ensure that terminology is firmly tied to underlying processes. Some authors have used the word anthropause as a synonym for positive environmental change caused by lockdowns. While an initial focus on potential benefits is understandable, conflating cause (change in human mobility) and effect (environmental responses) is unhelpful when using the term in a scientific context. Indeed, the way the anthropause concept was originally framed, it makes no assumptions about the sign of environmental responses and any associated conservation impacts1 (Fig. 1a). Emerging empirical evidence from the COVID-19 pandemic indicates a broad range of lockdown effects2,3.
Second, human mobility must be defined. COVID-19 lockdowns caused notable reductions in pedestrian counts and road, water and air traffic (and associated pollutant outputs), all of which likely caused environmental impacts1,2,3,4. For modern human pauses, it is reasonable to consider changes across the full range of human-mobility metrics, but comparisons with pre-industrial events inevitably need to focus on the environmental presence of people. In this context it is worth noting that humans might disappear from an area because they shelter, move elsewhere or perish, and that changes in human mobility can be driven by a variety of factors, including disease, natural and anthropogenic disasters, and conflict5. The ultimate drivers and proximate mechanisms affecting changes in human mobility are important research targets, but not part of the classification scheme itself (Fig. 1b). It is important to be mindful of the fact that many events will be associated with human tragedy and suffering1.
Third, operational definitions are required for the scheme’s spatio-temporal scales. While human pauses are easily ordered according to their duration, classifying their spatial extent is more challenging, for both conceptual and practical reasons7. The categories proposed here are pragmatic — spanning four orders of magnitude (Fig. 1b) — and will enable meaningful comparison of the environmental impacts caused by different types of human pauses.
Finally, it is important to clarify how the magnitude of events should be measured. Since human mobility dramatically increased over the past centuries, and will likely change further in the future, the magnitude of human pauses should be assessed against baseline levels for the time period and area under consideration, rather than in absolute terms. As illustrated by the COVID-19 pandemic, human mobility is not necessarily reduced to zero during an anthropause, and there can be substantial spatio-temporal variation in response levels. Preliminary analyses indicate that ~57% of the world’s population were under partial or full lockdown in early April 20202, and there were conspicuous local spikes in mobility once governments started allowing personal exercise1.
Source: Ecology - nature.com
