El Niño, the climate pattern typically linked to drought in Brazil's North and Northeast and to above-average rainfall in the South, is intensifying with global warming. That is the finding of a study published this Thursday (27) in the journal Science, according to a report by Folha de S.Paulo: the phenomenon's variability is at least 36.5% greater than in the pre-industrial period.
The conclusion is based on geochemical analysis of corals from the Galápagos archipelago, in Ecuador's equatorial Pacific, a natural archive holding a thousand years of climate records. The research was led by Julia Cole, a professor at the University of Michigan who specializes in paleoclimatology. According to Folha, the work confirms what recent observational data had suggested: El Niño is also being affected by climate change driven mainly by the burning of oil, coal and natural gas.
A thousand-year archive
Like air bubbles trapped in glaciers and tree rings, corals and their fossils preserve information about the climate of past eras. Cole's team estimated ocean surface temperatures around Galápagos over the last thousand years and compared the results with measurements from other Pacific corals. The location helps: the archipelago sits in the eastern equatorial Pacific, close to the region where El Niño is monitored by scientific convention.
To check whether the observed variability could be explained by natural causes, the researchers ran simulations with 12 climate models. The result showed a surge in variability over the last four decades, inconsistent with the natural oscillation that would be expected. The link between global warming and El Niño had long been presumed but was hard to prove, given the lack of ancient records and the phenomenon's own high natural variability. Fossilized corals allowed the team to work around that obstacle.
What it means for Brazil
El Niño favors everything from droughts to floods and, according to Folha, is expected to bring extreme events through the rest of 2026 and into 2027. In Brazil, that usually means harsher dry spells in regions such as the Amazon basin and the semi-arid Northeast, and excess rain in the South, a combination that weighs on farming, hydroelectric power generation and civil defense planning.
Confirming that human activity intensifies the phenomenon gives researchers a firmer basis for refining climate projections. For monitoring agencies and public officials, the study reinforces the need to treat El Niño-related extremes not as exceptions, but as a growing trend on a warmer planet.