This post is also available in: Dutch.
Although we assume that each year, in the period from October to January, a rainy season will present itself on Curacao, in the past there were years during which this ‘rule’ proved not to be true at all. It’s quite interesting to study the behavior of rain on our island, and its effects, and that is what we’ll examine in this article.
Cyclicity or not?
To gain insight into the erratic nature of rainfall activity on the island you can always look at the data from the meteorological service, but these data only give information about the last one hundred years or so. What was happening further back in history can be partially unraveled by using the sparse historical writings such as those stored in various archives. The scientific standard work regarding the ins and outs of the Curacao plantations in the 19th century has been compiled by Dr. W.E. Renkema. What you will not find in there are meteorological data, but you’ll find listings of crop yields of several plantations over the years. Based on these data the picture emerges that Curacao was not such a nice place to be in certain years. Unsuccessful or insufficient harvests were the rule rather than exception. Curaçao has never had a role as a production area of agricultural goods for export, due to the dry climate. But at certain times it was even so dry that there was not even enough food for local subsistence. During such periods of crisis, plantation owners were sometimes forced to sell slaves to neighboring countries, as there was not enough food to keep them alive on the local plantations.
We do not have enough data to conclusively determine whether there was a cyclicity in dry and wet years and how it looks, but the trend seems nevertheless suspiciously like 4 to 5 (extremely) dry years interspersed with 1 or 2 (somewhat) wet years.
The climate, nature and man
As has been described in several previous articles already, local nature has found a mode to survive under the prevailing conditions long ago. Curaçao nature even looks surprisingly alive and green, if you compare the average meteorological data to other places on Earth. In the Sonora desert in Mexico, for example, real ‘textbook’ desert conditions exist. But the average annual rainfall over there is not much less than on Curacao. Many local plants and animals have developed the capacity to put themselves in a sort of ‘drought sleep’, drought induced suspended animation, in anticipation of better times. A champion in this respect is surely the ‘Kokolishi di kalakuna’, scientifically known as Cerion uva. This endemic snail has the ability to survive years of drought, while locked up air and watertight with a homemade film, until the next rains come. A beautiful story around this behavior comes from Dr. Pieter Wagenaar Hummelinck, as a biologist on the island known as Shon Piet. During an expedition he collected a number of these snails and took them to his laboratory in the Netherlands. Years later, he accidentally spilled a glass of water on the box of snails. To his great surprise, the snails, of which he thought the shells were empty, suddenly started to march around in his office!
All these drought-adapted organisms celebrate when it eventually starts to rain. Especially reproductive activity is cranked up in high gear. Opportunistically taking advantage of the rain, as soon as possible.
Humans didn’t and don’t have such adaptation to drought. As long as no artificial solutions in the form of evaporators or ‘reverse osmosis’ water makers were invented, the dry periods were harsh. Travel journals of the late 19th century describe a clear picture. Curacao was no place where one could live very comfortable.
The future behavior of rain
Looking back at the past few years, something is wrong with the trend of five years dry, 2 years wet. Recent years were much wetter than we are accustomed to. If you ask for the opinion of meteorological experts, the answers start to become increasingly unambiguous. A few years ago, people were still reluctant to point the finger at climate change as a possible culprit. At this point in time, however, the proponents of the theory of climate change tend to beat the opponents. This document was written on January 8, 2012 in the Netherlands, where some areas just escaped from a potential disaster. It should have been freezing cold on this day, but it was 9 degrees Celsius outside. During the last couple of days before this day, it stormed and rained to such levels, that several essential sea walls were on the verge of breaking. On the news, scientists ans politicians were expressing themselves clearly. ‘All the result of climate change. No doubt about it, the future will confront us with more of the same, or worse’.
If climate change does indeed translate into more rain on Curacao, then we are awaiting times during which we will have to adapt rapidly to the wetter weather. And what about nature? The local ecology is used to adapt to changing circumstances. She is a specialist in this respect.