My Far Afield Column from June 25, 2009
Have you heard about the Butterfly Effect? It’s the theory that for certain complex systems, like the weather, we can never have enough information to predict the future accurately. Even if scientists understood weather perfectly, some variables are so sensitive it is impossible to measure them precisely enough to guarantee an accurate forecast.
The classic example which gives the effect its name is that a butterfly flapping its wings in China can add enough energy to the weather systems to determine, weeks later, whether a hurricane devastates Florida or fizzles out in the Atlantic.
Other effects do have well documented impacts that tie people together across thousands of miles. Strange as it may sound, the well being of the farmers and ranchers in Mercer County is closely tied with that of fishermen in Peru. Around these parts, the wind is generally from the west. South of the equator, it’s the opposite and the easterly trade winds blow warm surface water away from South America’s west coast. That allows cold, nutrient laden water to well up from the depths of the Pacific. Huge populations of anchovy, sardines, mackerel and other valuable sea life thrive in those waters and so do the fleets of fishermen that harvest them.
There’s another connection between those fish and farmers too. (I did warn you last week that my mind tends to wander.) Fishermen aren’t the only ones harvesting the bounty of the sea. Millions of seabirds eat countless tons of small fish from the sea. They fly back to the shore and do what birds do … to put it delicately … poop. Over millennia their deposits, called guano, have accumulated to be hundreds of feet thick in some places. The fish provide the birds with more protein than they need so the excess nitrogen goes into the guano.
Before the introduction of anhydrous ammonia and urea made from chemical processes in the 1940s, guano was the major form of nitrogen fertilizer in the world. It was so valuable, Chili and Peru fought a couple of wars in the 19th century for control of the deposits.
Every couple of years, however, the winds fail. The warm surface water sloshes back toward Peru. The fish retreat to find colder water, either in the depths of the ocean or further south along the coast. The fishermen’s nets come up empty. The birds leave to follow the fish or starve. The impact on the country’s economy is dramatic. The fishermen realized the winds usually failed in December so they started calling the event El Nino – the baby – referencing the birth of Christ.
For decades it was thought this was just a local event. It was bad for the fishermen of Peru, but not of much concern anywhere else. That changed in 1982 when an extremely strong El Nino caused weather disruptions around the world. Analysis of weather records found these weather aberrations were consistent with other El Nino years. Another strong event in 1997 confirmed the observations.
For Beulah, an El Nino means heat. Several of North Dakota’s warmest years are linked to El Nino events. Oddly, there doesn’t seem to be a clear link between El Nino and precipitation. However, with warmer weather comes more evaporation making drought conditions more likely. However, the added energy can make for more severe rain and snowstorms. In 1983, North Dakota had one of its hottest summers ever. Mercer County had nearly 15 more 90-degree days than normal that year.
The Pacific has been calm for the last couple of years not exhibiting an El Nino effect or its opposite – La Nina. In April, however, climate experts spotted some warmer than normal water gathering in the Western Pacific. This is like the first sign of a new El Nino. We will find out for sure as time goes on and the wind and water work out their inexorable patterns.
If this El Nino establishes itself the nets of the Peruvian fishermen will come up empty this Christmas just as the farmers and ranchers of Mercer County will wait and worry that their fields and pastures will brown and wither. Separated by thousands of miles and hundreds of years of culture, these two groups are linked by wind, water and weather.
While the world is large, in some ways these connections make it seem very small.