Simon Stanley finds out what (or who) was behind some of the extreme weather events of 2015. Photo by Vinh Dao.

They’re calling it Godzilla, the mother of all El Ninos, anticipated by some to surpass the power of the 1997-98 occurrence. This catastrophic event was attributed to more than 20,000 deaths and $30 billion of damage worldwide.

Since its reappearance in the spring of 2015, El Nino has never been far from the world’s headlines. Responsible for October’s devastating landslide in Guatemala, the deadly heat waves in India and Pakistan, and for supercharging what became the most powerful cyclone ever recorded in the Western Hemisphere, meteorologists on every continent continue to warn of what may lie ahead.

The Science
Under normal circumstances, due to the rotation of the earth and the direction of global air currents, a pool of warm surface water gathers in the western basin of the Pacific Ocean along the coastlines of Asia and Australasia. Over in the eastern Pacific, to fill the gap, cooler water rises upwards from deep below the surface in a process known as upwelling. It’s almost like a fan being blown across a puddle – the water ‘sloshes’ to one side, literally. Sea levels in the Philippines are thought to be 50cm to 60cm higher than those in Peru.

These warmer waters in the western Pacific cause the air above them to rise more rapidly. This warm, moist air encourages cloud formation which in turn leads to rainfall and the daily deluges we know and love. In the east we see the opposite, as cooler, dryer air settles over the South and Central American coastlines.

But from time to time, be it once every two years or 10, a chain of climatic events causes the east to west winds to die down (or even reverse direction), thus allowing the warmer waters to retreat back to the central and eastern areas of the ocean. This can cause water temperatures to rise by up to 4C (7F). It may seem small, but this alone has the power to raise global temperatures and dramatically increase the likelihood of floods, droughts and extreme weather all over the planet.

For the Pacific-facing regions of South America, typically some of the driest places on earth, El Nino means rain, storms, floods and landslides. In Peru, a country which relies heavily on its fishing industry, El Nino is bad news. It was here in the late 18th century that the phenomenon was first observed and recorded. The fishermen called it El Nino, the Christ Child, as it would often reach its peak during the Christmas period.

In addition to turbulent weather, heavy rains and warmer temperatures, the slowing of the upwelling process starves Peru’s coastal waters of the nutrients which normally rise up from deep below the ocean. When El Nino’s in town, Peru’s precious anchovy stocks simply disappear.

As For Asia…
On the other side of the coin, and the other side of the ocean, the effects are reversed. With the warmer waters shifting eastwards and away from Asia, so too goes the moisture-rich air, the resulting clouds and, ultimately, normal levels of rainfall. While freak weather events like Saigon’s apocalyptic downpour of September 15 might suggest otherwise, Southeast Asia has been in drought for most of the year. According to Tuoi Tre News, 2015’s erratic (and late) wet season brought just 60 percent to 80 percent of normal rainfall levels to Vietnam.

Many of the country’s reservoirs have been critically low throughout the year, threatening livestock, crops and hydro-electric power production. Furthermore, reduced rainfall in the upper Mekong regions of Laos and Cambodia allowed salt water from the sea to penetrate further into the Mekong Delta by an estimated 50km to 80km, leaving many of the region’s communities with crippled irrigation systems, dead fish and a lack of fresh water. Speaking to Vietnam News, Dr. Le Anh Tuan, deputy head of the Institute of Climate Change Research at Can Tho University, said that freshwater volume in the Mekong Delta in 2015 had dropped to between 60 percent and 65 percent compared to previous years, although he was keen to point out that long-term global warming was still a major culprit.

Elsewhere in the region, Thailand has suffered its worst drought in a decade while Cambodia’s Tonle Sap River ran at its lowest level in 30 years. In the Philippines, where low rainfall and high temperatures ravaged the country’s agriculture, electricity providers struggled to cope with the extra demand for air-conditioning.

It Doesn’t End There
With less rain comes more heat. Coupled with a longer than normal wet season, El Nino created the ideal conditions for mosquitoes to breed and flourish. More mosquitoes means more disease and a sharp rise in dengue fever was reported in both Vietnam and Cambodia as El Nino took hold. Ho Chi Minh City’s hospitals treated nearly 10,000 infected patients in the first nine months of 2015, up 66 percent compared to the same period in 2014.

As for the smog that choked Saigon and most of Southeast Asia throughout October – yes, El Nino was (partly) responsible. Indonesia’s annual peat fires, many of which are started deliberately to clear land for palm oil plantations, burned far longer and further than normal years when the usual extinguishing monsoons did not arrive on time. While the results of this year’s fires are still being played out, the extra smoke caused by 1997-98’s El Nino is thought to have killed 10,800 people in Southeast Asia alone. Unfortunately, many experts (including NASA) feel that 2015-16 could be even worse.

So if you thought the weather these past few months has been crazy, you’d be absolutely right, although the world clearly has far greater things to worry about than your waterlogged Honda as 2016 approaches. But at least now you know who to blame.