The current El Niño may hold lessons for how to deal with a warming planet

El Niño is the name given to unusually warm ocean waters in the equatorial Pacific, seen above in red. El Niño effects weather patterns across the globe.

The extreme weather events unfolding around the world as a result of El Niño may give nations an opportunity to learn how to plan for the expected effects of global warming.

El Niño is essentially a “mini global warming" event, Trenberth explains. It arises from a build-up of heat in the waters of the equatorial Pacific Ocean. The warm ocean waters and higher sea levels begin in the western tropical Pacific and then spread to the central and eastern Pacific. The warm tropical ocean releases additional water vapor into the atmosphere through evaporation.

When warm air rises from the oceans to higher levels of the atmosphere, the moisture in the air “rains out,” in a process called “latent heating of condensation.” As that moisture gets released, it leads to additional warming of the air and invigorates weather systems around the world, especially in the eastern Pacific. What’s more, changes in ocean temperature become amplified over dry land, according to one study.

The effects of an El Niño can be overwhelming: The summer of 2015 saw a record number of hurricanes and typhoons in the Philippines, Japan, China, Taiwan and Vietnam — the largest number of Category Four and Five storms on record by a substantial amount, according to Trenberth.

Changing weather patterns also brought a major drought to Indonesia, with a tremendous number of wildfires, while here in the US, major flooding occurred along the Mississippi River, especially in the state of Missouri. In fact, Trenberth says, during November and December the state of Missouri had three times its normal rainfall. The previous record had been about twice the normal amount of rainfall.

All of this means that countries around the world and some states in the US need to take lessons from this relatively short-term surge in temperatures and begin planning to cope with the more persistent, long-term changes likely to arise from climate change, Trenberth says. 

Heavy rainfall in California, for example, will bring substantial relief to agriculture and help restore the parched soil in many parts of that state. But unfortunately — in this case — California has a well-developed system of flood protection, which means a lot of the water now flowing back into Southern California runs into the Los Angeles River and back out to sea, instead of going back into the earth to replenish groundwater supplies.

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Taxonomy

• Climate Change
• Climate Change Adaptation
• Climate Change Resilience