Many people are familiar with the uncertainty and fear associated with the weather event, El Niño; however, few truly understand the complexities and dynamics of how it occurs. In March of 2015, NOAA’s Climate Prediction Center reported that a weak El Niño was upon us, however many believed that it would simply fizzle out, without gathering enough energy to be a serious concern. As the summer arrived it became evident by the frequent, massive tropical storms in the Pacific that this El Niño was designed to be one of the strongest on record. Scientists are worried that this year could be reminiscent of the 1997-98’ event which was filled with furious storm clouds and caused 23,000 deaths accompanied by $35 billion in global damage.
In simplest terms, El Niño is a unique weather phenomenon that occurs irregularly (every 2-7 years) and behaves unpredictably, making each event unique in its nature and storm patterns. What they all have in common is the change in wind patterns which drives this change in usual weather patterns. During an El Niño year, the strong trade winds that blow East to West in the Equatorial Pacific weaken, resulting in sea surface temperature rising which alters worldwide weather patterns. The Global Conveyor Belt refers to the temperature and density driven deep-ocean currents that circulate around the world. Normally the cold, dense water from the poles sinks and moves southward, as warm, less dense water moves to the surface to create convection currents. However, because the weaker trade winds create warmer global ocean conditions, the temperature change in ocean waters is not as extreme, and results in cold water resting in the depths and warmer water at the surface. For example, on average Indonesia’s sea surface temperature is 8 degrees Celsius warmer than the waters of Peru. However, weak trade winds warm Indonesian water which is then pulled Eastward by gravity, simultaneously Peru does not receive the cool currents from the Northern waters, creating a wetter, warmer climate. El Niño thus causes the Eastern and Central Pacific temperatures to rise, while intense rainfall shadows the Eastward movement of the warm pool of water originating from Indonesia.
Already, NASA data has shown that 2015 has the highest temperature averages on record, and scientists fear that global climate change coupled with El Niño will cause some of the strongest and most deadly weather events on record. Due to the changes in weather, Peru and California are prone to large rainstorm events, while Indonesia and Australia experience extra dry conditions. Proof of this is already evident as there has been no rainfall, characteristic of the tropics, in Indonesia recently which has led to massive, unstoppable forest fires. If rain were to fall in California it might be able to help ease the effects felt from their massive drought, but they must prepare for the natural disasters such as mud slides to accompany this sudden surge of incoming water.
NOAA declares an El Niño event when the averages for the Pacific equatorial regions are consistently 0.5 degrees Celsius above the region’s baseline sea surface temperature for 3 consecutive months. In October of this year, NOAA revealed that temperatures have soared to over 2 degrees Celsius above historical baseline. El Niño is based on ocean behavior, but how is it directly affecting the oceans? Firstly, cool ocean waters serve as the Earth’s largest Carbon Dioxide sink, absorbing 90% of the excess atmospheric Carbon Dioxide. But if there is less cold water available to absorb Carbon Dioxide, then these extraneous greenhouse gases will remain in the atmosphere and only reinforce the warming of the climate. Additionally, hurricanes and tropical storms greatly increase in intensity and frequency during El Niño years. Possibly the most notable and important effect of this year’s El Niño is the hastening of coral bleaching worldwide.
When the water surrounding coral reefs become too warm, corals expel the microscopic algae living inside them, which serves as their life source and provides their vibrant coloration. Without their symbiotic relationship, corals turn white and die leaving being a Calcium Carbonate skeleton devoid of life. Currently the world’s oceans are experiencing the largest coral die off in history, which is bad for both the ecosystem and the ecotourism based economies that rely on the reefs. Climate change is to blame for these bleaching events, but a strong El Niño may spell disaster for the world’s most beautiful coral reefs.
It is important to note that scientists, “caution people to think not in terms of certainties but in terms of probabilities”. Each El Niño is unpredictable and creates unique storms that do not always follow historic patterns. Though it is obvious that El Niño 2015 has already causes devastation to reefs and Indonesian forests, it might cure California’s drought and perform other climate miracles in the coming months. Many economies are actually boosted due to more mild weather conditions and much needed rain; however, it seems to cause more harm than good as lower crop yields, droughts, floods, and disease blossoms in places hit hard by raging storms.
This incredible weather event occurs naturally, every 2 to 7 years, but they are getting increasingly severe and costly due to the already warmer waters as a result of climate change. El Niño cannot be stopped, by more sustainable practices and reduction of greenhouse gas production could certainly create conditions that would not enhance the effects of El Niño as we are seeing today.