These days we have received some news from Brazilian friends we visited a few years ago. They live in Foz do Iguazú, a sleepy Brazilian town next to one of the seven wonders of nature, the Iguazú Waterfalls. The town is now even more ghostly than usual due to the lack of tourists, its primary source of revenue. The national park enclosing the waterfalls was closed in mid-March. And apart from visiting the waterfalls, there is not much you can do in the town. There is a beautiful animal park of tropical birds; the ITAIPU hydropower plant, one of the largest hydropower plants in the world, is a twenty-minute bus ride away; and the triple border, where you can look at three countries, Brazil, Argentina and Paraguay, at the same time.

So, no more tourists in Foz do Iguazú! But this was not the main story our friends had in store for us. They sent us pictures of the waterfalls that were hardly recognisable. Instead of hundreds of waterfalls with masses of water plunging dozens of meters into the depths, the current images show brown cliffs, exposed rocks and a thin stream where once a mighty river flowed. The abundance of water that covered the entire valley had subsided, giving way to a brownish, desert-like landscape. The Iguazú River is experiencing a major drought. While droughts in these months of the year are not unusual, and the water flow of the Iguazú River and the waterfalls always decreases in these months, the current pictures do not conform to the usual weather patterns. Instead, the desolating pictures of the dried-up waterfalls are another set of pieces in the larger mosaic of climate change. The entire south of Brazil has experienced historically low rainfall over the last few months.

Over the last few weeks, I have read lots of reports about the positive environmental effects of COVID-19. In fact, air pollution has decreased substantially due to the near-collapse of air travel, abandoned cars, halted industry production and slowed down agricultural production. But despite the frantic news reports emphasising time and again that COVID-19 is the crisis of a century, I have the unpleasant feeling that COVID-19 will pale into insignificance when compared with the climate crisis lurking in the background.