southeast-brazil-drought-2014-2015

The study investigates the 2014/15 drought in southeast Brazil, specifically focusing on the impacts in São Paulo. Using a multi-method approach including historical observations and climate model simulations, the researchers found limited evidence that human-induced greenhouse gas emissions increased the hydrometeorological hazard. Instead, the severe impacts on water supply were primarily attributed to rapid population growth and increased water consumption.

• The drought in southeast Brazil from January 2014 to February 2015 was characterized by a complete absence of South Atlantic convergence zone (SACZ) episodes during the summer of 2014.
• The 2014/15 drought caused severe water shortages in São Paulo; the Cantareira water supply system dropped to 5% of its capacity by January 2015, reducing the number of people it supplied from 8.8 million to 5.3 million.
• Observational data indicates that the 2014/15 precipitation deficit of 435 mm has a return period of approximately 20 years, and that dry extremes in the region showed a barely significant decrease up to 2013.
• Simulations using the weather@home framework suggest that anthropogenic greenhouse gas emissions have actually made dry precipitation extremes less likely in southeast Brazil, shifting a 1-in-20-year event to approximately a 1-in-30-year event.
• There was no detectable change in the difference between precipitation and evaporation (P − E) due to human-induced climate change, as an increase in evaporation cancelled out the increase in precipitation.
• While CMIP5 ensemble simulations showed an increase in the risk of low precipitation (with FARs greater than 0.167), they confirmed the null result for P − E.
• The study concludes that the 2014/15 event's large impact was likely driven by accelerated population growth and changes in water use rather than an increase in hydrometeorological hazard from human-induced emissions.
• The drought was associated with a public health impact in São Paulo, where dengue cases tripled in 2015 compared to 2014.

APA

World Weather Attribution (2015). southeast-brazil-drought-2014-2015. https://www.worldweatherattribution.org/southeast-brazil-drought-2014-2015/

Chicago

World Weather Attribution. southeast-brazil-drought-2014-2015. 2015. https://www.worldweatherattribution.org/southeast-brazil-drought-2014-2015/.

Wikipedia

{{cite report |author=World Weather Attribution |title=southeast-brazil-drought-2014-2015 |date=10 September 2015 |url=https://www.worldweatherattribution.org/southeast-brazil-drought-2014-2015/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{worldweatherattribution2015southeastbrazildrought20142015, author = {{World Weather Attribution}}, title = {{southeast-brazil-drought-2014-2015}}, institution = {World Weather Attribution}, year = {2015}, month = sep, url = {https://www.worldweatherattribution.org/southeast-brazil-drought-2014-2015/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }