Between 1877 and 1878, an extreme El Niño occurred and about 23 million died primarily due to famine and drought. A similar event happened in 1982-83 but did not cause as many deaths with emergency provisions and infrastructure in place. Between 1997 and 1998, the extreme weather phenomenon claimed 23,000 lives and caused about $35 billion in global damages. Now, experts say humans must brace themselves as El Niño events may double through the next 100 years because of global warming.
The usual El Niño phenomenon normally happens in the western portion of the Pacific.
During an extreme El Niño event, the usually cold eastern portion of the Pacific Ocean hits a surface temperature of over 28 degrees Celsius. With the El Niño developing on the opposite corner of the largest ocean in the world, massive rainfall variations take place.
Findings of the study titled "Increasing frequency of extreme El Niño events due to greenhouse warming" appeared on the Nature Climate Change journal.
"El Niño events are a multi-dimensional problem, and only now are we starting to understand better how they respond to global warming," said Dr. Agus Santoso of the ARC Center of Excellence for Climate System Science and one of the authors of the study. "We currently experience an unusually strong El Niño event every 20 years. Our research shows this will double to one event every 10 years."
To look into the possible effects of global warming, the authors of the study used climate models that spanned 200 years from 1891 to 1990 and took into account current and projected carbon dioxide levels and factors influencing global warming.
The scientists noted the difference between the two centuries covered. They noticed the increase in the number of El Niño events between 1991 and 2090 compared to the events between 1891 and 1990.
Lead author Dr. Wenju Cai of the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Australia has warned of impending extreme weather that the human race must expect in the next decades.
"During an extreme El Niño event countries in the western Pacific, such as Australia and Indonesia, experienced devastating droughts and wild fires, while catastrophic floods occurred in the eastern equatorial region of Ecuador and northern Peru," explained Cai.
"We are due for a big one because the last extreme El Niño was in 1997/98," said Cai.
