  During COVID-19, draconian countermeasures forbidding non-essential human
activities have been adopted worldwide, providing an unprecedented setup for
testing sustainability policies. We unravel causal relationships among 16
environmental conditions and human activity variables and argue that, despite a
measurable decrease in NO2 concentration due to human activities, locking down
a region is insufficient to significantly reduce emissions. Policy strategies
more effective than lockdowns must be considered for pollution control and
climate change mitigation.
