Extreme heat and fires linked to climate change in Brazil

Over 60 million people in Brazil will contend with extreme temperatures from August 22-25, as devastating wildfires continue to destroy forests and wetlands ecosystems, affecting human health and disrupting daily life. The heat that Brazilians will experience in the coming days has a clear connection to climate change, with forecasted high temperatures made 5 times more likely due to global warming, primarily caused by burning fossil fuels.

Impacts: 

• Temperatures as high as 39°C are well-above the late August normal, with some locations in Central Brazil (Centro-Oeste) experiencing temperatures 7°C above what is normal for this time of the year. Northern regions (Norte) will face temperatures up to 6°C above normal.

• So far this year, more than 760,000 hectares of land have burned in the Amazon and 1.3 m hectares in the Pantanal region, which are now impacted by the climate change-driven heat. Climate change made the wildfires in Pantanal 40% more intense, a recent study found. Long-term, persistent dry air and deforestation has reduced moisture for rainfall, heightening fire risk. 

• On August 20, the concentration of microparticles known as PM2.5, a cancer-causing pollution from heat-induced fires, reached levels 11 times higher than World Health Organization recommendations. Smoke from fires in the Pantanal and Amazon regions reached at least 10 Brazilian states, as well as Bolivia, Paraguay, and Peru.

• Increased cases of asthma, pneumonia, and sinusitis have been reported due to the deteriorating air quality.

• In addition to heat, severe drought conditions persist across much of Brazil, with worsening impacts on agriculture and water supply expected.

Heat Risks: 

• Daily average temperatures are expected to reach Climate Shift Index (CSI) levels of 5 for at least a day, in cities including São Paulo, Campinas, Guarulhos, and Jacarei in São Paulo; Manaus in Amazonas; Natal in Rio Grande do Norte; Belém in Pará; Macapá in Amapá; Campo Grande in Mato Grosso; Sorriso in Mato Grosso do Sul; Porto Velho and Ji-Paraná in Rondônia; and Boa Vista in Roraima.

  •  A CSI level 5 indicates that human-caused climate change made this extreme heat at least 5 times more likely, signifying an exceptional climate change event. 

  • Temperature anomalies of up to 8°C above normal are expected in cities in the central and northern regions of Brazil, while anomalies up to 10°C will be possible in parts of the state of São Paulo. This means that temperatures are expected to be up to 10°C above the usual average for this time of the year because of climate change.

See table below for some of the cities most impacted by the extreme heat driven by climate change. 

Use the Climate Shift Index global map to see CSI levels in your city and region, and see our FAQs to learn about the CSI in both English and Spanish. 

What do experts say?

Dr. Andrew Pershing, VP of Science at Climate Central, said: 

"Brazil is facing extreme temperatures despite being in the middle of winter. This stark reality highlights the clear impact of climate change,” said Andrew Perching. “As long as we continue to burn fossil fuels, we will continue to see these alarming heatwaves and the devastating wildfires they fuel."

To request an interview with a Climate Central scientist, please contact Abbie Veitch at aveitch@climatecentral.org