Climate Risk Assessment - Rio Branco, Brazil

1. Pollutants in the air we breathe are detrimental to human health. Long-term exposure to air particulate matter in Acre, Brazil, has decreased the average life expectancy by an estimated 2–3 years. Smoke from rural fires is the major source affecting air quality at Rio Branco. 2. Observations of fine particulate matter (PM2.5) have become available in Acre through the Purple Air project. Uncorrected data shows that in Rio Branco, an estimated 125 days exceeded the WHO’s daily guidance for PM2.5 levels during the dry season in 2019. 3. Satellite observations indicate that rural fires are densely distributed around Rio Branco itself, North Rondônia, as well as northeastern and central Bolivia. 4. The source of the smoke arriving at Rio Branco within 6 days comes from nearby areas to the north and east (64% of the time), from the south (31% of the time) or from the east (5% of the time). The average 6-day air parcel spends half of its time inside a radius of just 266 km around Rio Branco. 5. Rural fires around Rio Branco are expected to increase due to changes in climate by 38% within 500 km by 2090, under the fossil fuel intensive IPCC scenario. Our analysis also shows that the number of smoke-producing rural fires within two days of wind transport of Rio Branco is expected to increase by a third by 2090. This does not include the effect of increased tree mortality in the region or changes in land cover and land use. 6. To improve air quality, fires must be reduced now from their present level. For more information about this analysis, or Woodwell’s other climate risk assessments, please contact us at policy@woodwellclimate.org. To learn more about Woodwell, please visit our website at woodwellclimate.org.