In tragedy comes unforeseen enlightenment. Three days in September 2001, for instance, bolstered the theory that contrails had a role in global warming. With planes grounded across the United States, the line-shaped clouds vanished from the skies, causing the daily variations in high and low temperatures to increase by 1.1°C. Nineteen years later, this chance detail of the 9/11 lockdown would prove to be a microcosm of Covid-19 and the raft of natural phenomena it has caused.

Exploring this is The Year Earth Changed, which is the latest documentary reflection on our strange times. In a series of case studies, we see how lockdowns have affected the environment and the many different species with which we share it, from dolphins and deer to turtles and jackass penguins.

Beautiful images flood the screen, from gliding shots of deserted international cities to close-ups of gorillas pottering in the lush Ugandan wilderness. Meanwhile, David Attenborough’s narration guides us through each story with sobering figures. Within days of the lockdown, we are told, Los Angeles recorded its lowest air pollution in 40 years. In China, toxic gases halved. And in the Punjabi city of Jalandhar, the Himalayas became visible for the first time in 30 years.

The Year Earth ChangedMore curious than this, however, is the effect our absence has had on animal behaviour. For example, the engines of desperate safari tours no longer drown out Cheetahs calling to their cubs, making it easier for the big cats to feed their litter and evade nearby lions and hyenas. Gone too are the immense tourist ships off the Alaskan coast, prompting humpback whales to communicate not only more often but in ways hitherto unseen by local researchers. Most unusual is how some mothers have left their calves alone, heading off to feed with other adults safe in the knowledge that their offspring are within earshot.

As we learn of stories from every corner of the world, there is a nagging concern that all of this is temporary. With the end of lockdown now in sight, there will soon no longer be 114 million fewer tourists, a 17% reduction in shipping, or a 6% fall in C02. But can we maintain at least some of this newfound harmony with the natural world? Yes, but the answers are found in regulations and restrictions, which are anathema to many. Hopefully, this urgent and typically beautiful documentary will give a sense of perspective to its viewers. It did for me.

The Year Earth Changed and second seasons of Tiny World & Earth At Night In Colour are releasing on Apple TV+ on 16th April.