Lockdown is a unique chance to see how human activity affects

WHEN I sat down at my kitchen table at the tail end of winter to write my first column under lockdown, I didn’t think I would still be there come midsummer. That piece was about the health benefits of contact with nature and how to get them in a locked-down world.

I was reminded of this last week during a bike ride with my wife through the still-quiet streets of central London. We swung through St James’s Park and stopped at the lake to admire the pelicans. The sun was shining, the water was