As some of you know, I live in the centre of Brussels, where green space is scarcer than the hair on my old math professor’s head in the second year of university. I, therefore, was a bit shocked that a couple of weeks ago, a fence blocked off part of the already limited patch of greenery around the corner. ‘Dog zone’, the plaque on the newly installed enclosure read.

I truly was a tad annoyed at first. But when I saw two four-footers testing out their new playground, I just could not hold back a smile at the sight of their playful fight. Grumpiness gone. Nonetheless, the whole situation had sparked a question. While it is easily measurable how much green space we give away to pets in our cities, it is less obvious how much of humankind’s carbon budget is eaten away by them –literally.