"Brazil's indigenous people face a serious threat to their survival with the Covid-19 pandemic," writes the 76-year-old photographer, who demands that Bolsonaro guarantee the indigenous people's safety and stop the intrusion into their lives.
The letter also has a digital name collection with more than 50,000 signatures, including from a number of celebrities such as Madonna, Brad Pitt, Paul McCartney and Meryl Streep.
The Amazon is one of the regions in the country that has been worst hit by the pandemic.
Even before the pandemic, Sebastião Salgado had plans for a new large photographic suite about the Amazon - to engage the world in saving the rainforest.