The coronavirus has achieved in months what continual attempts at environmental treaties have failed to deliver: clean and breathable air. The World Health Organisation considers an air quality index of over 25 to be unsafe. Before it enforced lockdown, in the world’s most polluted city, Delhi, the AQI level was usually a severe 200 on a good day, though during peak pollution periods last year they soared well into a life-threatening 900 and sometimes off the measurable scale. But as cars were taken off the roads and factories and construction grounded, AQI levels have now fallen below 20 and blue skies are to be seen again over the previously smogbound city. It’s been the same in such previously toxic capitals as Bangkok, Beijing, Sao Paulo and Bogota, all of which have seen similar transformations in air quality, while, for the first month of the outbreak, pollution levels in China fell 25 per cent across the country despite Hubei province being the only area under quarantine.

However, there are some downsides to all this － one very obvious being that, having been confined to barracks, the citizens of these countries are not at liberty to enjoy these much improved conditions.