First, the data: 8,233,788. These are the inhabitants of Catalonia as of this Thursday. Up to 72,150 more people than a year ago and 32,000 more than six months ago. We continue to grow due to the arrival of people from abroad. If it were for the birth rate of the natives, we would lose population. Right now there are 2.15 million citizens born outside the State, 26.2% of the total. That is, one in four inhabitants.

A 2017 scientific study claimed having one fewer child was the most effective way to fight climate change – more impactful than going vegan or ditching your car. A small but growing number of people have consciously chosen not to have children to help the planet. Yet sacrifice may prove unnecessary. After half a century of population explosion and global overpopulation alarms, the problem now appears reversed: population decline. "We're not preparing for what's coming. Just as rapid population growth disrupted the world, the coming population drop will be equally – or more – swift and disruptive", warns Darrell Bricker, Ipsos researcher and co-author (with John Ibbitson) of Empty Planet.