The World Health Organization (WHO) noted that India is among the countries facing a high or very high health risk as the intensification of the El Niño phenomenon alters weather conditions in South Asia.
This forecast comes against the backdrop of an increase in dengue fever cases in various regions of the country.
A study conducted by the University of Michigan reveals that El Niño events have become nearly 40% more intense over the last four decades. This conclusion was reached by analyzing corals found in the Galapagos Islands, which serve as records of ocean temperatures with a history of up to a thousand years.
The work, published in the journal Science, demonstrates that recent El Niño episodes have surpassed the strength of any previous record before 1850. Furthermore, scientists identified a direct correlation between the greater intensity of this phenomenon and the rise in global temperature.
To obtain these results, the team investigated samples from 13 Galapagos corals, covering both active colonies and ancient fragments. As these organisms grow, they deposit layers of calcium carbonate, each preserving data on the water conditions of that specific period.
The specialists examined the concentration of calcium and strontium in the coral skeletons, as well as certain oxygen isotopes. These two analytical methodologies allowed for the precise estimation of water temperature.
The findings were notable for their consistency; while records prior to the last fifty or forty years indicated relatively smaller magnitude El Niños, the most recent events showed a constant prominence. There are no historical precedents where El Niños have reached the strength observed currently.
Julia Cole, a professor and head of the Department of Earth and Environmental Sciences at the University of Michigan and the study's lead author, commented on the discovery.
The El Niño phenomenon occurs when tropical Pacific waters warm above normal levels. Normally, trade winds transport warm water from South America to the region of Australia. When these winds weaken, some of this water returns eastward toward South America, causing changes in atmospheric circulation and altering rainfall distribution.
Although originating in the Pacific, El Niño can affect the climate in various parts of the globe. Among the possible consequences are several environmental impacts.
The team also used climate models to verify whether natural factors could justify this change. The simulations took into account data on volcanic eruptions and fluctuations in solar activity over millennia.
None of the tested variables, such as volcanic eruptions or solar variations, managed to replicate an intensity change comparable to that seen in recent El Niños.
For Cole, this strengthens the theory that global warming is contributing to the intensification of the phenomenon. The researcher stated that 'El Niño is a major source of climate extremes, and if it is getting stronger, the impacts will too.'
The current El Niño manifests itself on an already warmed planet due to the increase in greenhouse gases. This combination has the potential to further raise temperatures and worsen effects on ecosystems, infrastructure, and the population.
For the researchers, this result serves as additional reinforcement to the urgency of controlling global warming and reducing dependence on fossil fuels.
