Weather has obviously been one of the most important drivers of human civilization since the beginning of recorded history. Cyclical weather patterns have created human migration, affected the health of humanity through food production, and made some nations wealthier over time and some continuously poorer.
Countries on the Pacific Ocean have been subjected to the recurring periods of the warming El Niño–Southern Oscillation and its opposite La Niña periodic cooling of ocean surface temperatures in the equatorial band of the Pacific. Evidence is strong for El Niño events during the early Holocene epoch 10,000 years ago.
Great global economic effects can be illustrated in the nearly 500 percent increase in the price of soybeans between 1970 and mid-1973. The supply of fishmeal used in animal feed sourced from the western coast of South America began to be disrupted with the strong El Niño in 1965. Another El Niño episode in 1972 delivered a devastating blow, and soy prices skyrocketed. This came about despite the fact that from the early 1970s, Latin America, led by Brazil, began to emerge as a major soybean producing area. In 1974, Brazil’s production passed that of China, and in 1975 Latin America’s total production—major producers being Brazil and Argentina—passed that of Asia.
The weather pattern created a global economic change. In 1972, approximately 30 million tons of soy was used as animal feed. Today it is 180 million tons. In 1980, 77 percent of fishmeal production was used for feeding pigs and chickens. That percentage is now 40 percent.
El Niño events occur at two- to seven-year intervals with varying strengths and with different effects on the east and west of the Pacific Ocean. This leads to intense storms in some places and droughts in others. On our side on the world, El Niño causes cooler ocean surface temperatures. As warm water spreads from the western Pacific to the eastern Pacific, it takes the rain with it and can cause extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific.
La Niña occurs as strong winds blow warm water at the ocean’s surface away from South America, across the Pacific Ocean towards Asia. In March 2008, La Niña caused heavy rains over Malaysia, the Philippines, and Indonesia.
PAGASA (Philippine Atmospheric, Geophysical and Astronomical Services Administration) has been monitoring the formation of a La Niña since July and at that time said “there is more than 50 percent chance that a weak La Niña will develop in either late October or November 2020.”
On October 29th, the World Meteorological Organization of the United Nations said, “La Niña has developed and is expected to last into next year. The latest seasonal forecasts indicate normal rainfall in Southeast Asia. La Niña is often associated with wet conditions across large parts of Southeast Asia, Australia and the latest seasonal outlook is consistent with historical La Niña conditions.”
PAGASA confirmed that also in October with “Rainfall forecast from October 2020 to March 2021 suggests that most parts of the country will likely receive near to above normal rainfall conditions. In addition, five to eight tropical cyclones, most of which are landfalling TCs, are expected to enter/develop in the Philippine Area of Responsibility.”
Now, PAGASA says: “These meteorological conditions indicate the onset of Northeast Monsoon [Amihan] season in the country.” It is going to be a “wet-not-white Christmas.”