The planet’s wildernesses are shrinking so fast that they could vanish within a century, a report has warned. According to the study, 1.3 million square miles of once pristine landscape have been tarnished by large-scale human activity in the last 25 years – about a tenth of the total worldwide. Almost a third of that was in the Amazon, despite deforestation in Brazil having slowed in recent years. Central Africa, home to thousands of endangered species including forest elephants and chimpanzees, accounted for a further 14%. Although around 20% of the world’s land – equivalent to around 11.5 million square miles – is still classed as wilderness, the report warns that any further reductions could be catastrophic. As well as losing many animal and plant species, the consequences for climate change would be devastating, since so much carbon is stored in forests. “Without any policies to protect these areas, they are falling victim to widespread development,” said Dr James Watson of the University of Queensland. “We probably have one or two decades to turn this around.”

In this context the pros and cons of tourism are a conundrum. One can argue that tourism helps pay to keep the wild places of the world wild. It helps pay for the soldiers who now have to guard the rhinos and elephants in Botswana and Namibia, for instance. Indeed, the tourist income is so important that protection of wildlife is a national priority. On the other hand, if my sister and her husband had not been to Namibia years ago, I would have known nothing about it. In general, I am in good company. So when my wife and I had a (spectacular) visit to Namibia this summer I was surprised to see so many people. The number of visitors climbs every year, as do the number of game lodges. I took a photos of what looked like an army climbing single file up one of the famous giant sand dunes. My point? How long can Namibia, for instance, maintain its wonderful deserts and its wild life? I am part of the problem; maybe you are too?