The Amazon in Brazil is on fire – how bad is it?

Thousands of fires are ravaging the Amazon rainforest in Brazil – the most intense blazes for almost a decade.
The northern states of Roraima, Acre, Rondônia and Amazonas have been particularly badly affected.
However, images purported to be of the fires – including some shared under the hashtag #PrayforAmazonia – have been shown to be decades old or not even in Brazil.