A combination of clouds, smoke and a cold front left the Western Hemisphere’s largest city under the cover of darkness in the middle of the day on Monday, according to The Washington Post.
“The smoke didn’t come from fires in the state of Sao Paulo, but from very dense and wide fires that have been happening for several days in [the state of] Rondonia and Bolivia,” said Josélia Pegorim, a meteorologist with Climatempo. “The cold front changed direction and its winds transported the smoke to Sao Paulo.”
The number of forest fires in Brazil has risen 80 percent this year, according to the National Institute for Space Research (INPE), as the region “has been undergoing a prolonged drought.”
The Post noted that the Amazon was largely considered fireproof in the past, but due to climate change and deforestation, the area has witnessed a dramatic increase in wildfires.
“Wildfires in the Amazon are not natural events, but are instead caused by a combination of droughts and human activities. Both anthropogenic climate change and regional deforestation are linked to increases in the intensity and frequency of droughts over Amazonia,” according to British researchers writing earlier this year in the Conversation.