El Niño and the Drought

By Isobel Whitcomb '17
Environmental Columnist

Since the beginning of 2015, meteorologists have been predicting a “massive” El Niño due to hit this winter. For native Southern Californians, this prediction may sound familiar; however, El Niño may be a brand new concept for those hailing from out of state. El Niño is a cyclical weather pattern that occurs every 4-8 years in the Eastern Pacific Ocean (the side of the Pacific nearest to the Americas). Originating off of the coast of Peru, it is triggered by a sudden change in the trade winds that normally blow in from the East. When these trade winds don’t blow in, the Eastern Pacific’s normally cool sea surface temperatures increase rapidly, causing adverse weather conditions throughout throughout the west coast of the Americas. These changes in weather patterns typically include drought in the Amazon and heavy rains throughout California.

Not all El Niños are equal in magnitude. In 1997, El Niño rocked weather patterns across the entire earth, causing massive drought and wildfires in Indonesia and bringing an Indonesian Monsoon to California. This winter’s El Niño is predicted to be of similar magnitude. It could bring the most rain that California has seen since at least 1997, if not the most rain ever recorded in the state. In the midst of the worst drought in California’s recorded history, it’s understandable that most Californians are excited about this prospect. Months of heavy rain is a welcome change to endless sunshine and blistering heat. However, it’s important that we have a realistic idea about what this winter’s El Niño could mean. Will El Niño end our drought? The answer is almost certainly a “no.” So what does this year’s El Niño mean?

Experts agree that rain will provide a respite to the parched conditions that have prevailed in California for the past five years. However, Californians must remain cautious about their water consumption, even in the face of rain. This is largely because even experts don’t know exactly how El Niño will affect California. Our current lack of knowledge is due in part because El Niño’s effect depends largely on which part of the state it impacts. While rainfall in Northern California could blanket the Sierra’s in snow and fill the drying reservoirs of the Central Valley, an El Niño that is restricted to Southern California would largely run straight into the ocean, bringing with it all our waste and pollutants.

Then there is La Niña, the lesser-known sister of El Niño, which often comes the following winter. In the year following El Niño, La Niña usually brings a reversal of the previous year’s extreme weather conditions. For California, this could mean an intensely dry year following this year’s El Niño. This was true for California in 1998-1999, following the heavy rainfall of the 1997 El Niño.

In recent decades, El Niño years have become increasingly common as part of a pattern of weather extremes that accompanies global warming. Their increasing frequency is most likely due to steadily rising average sea surface temperatures compounded with the sudden rise in sea surface temperatures that precedes El Niño. The fact that 1997 brought one of the heaviest rainfalls in California’s recorded history, and that this winter could once again top that record, is the flip side of the current drought conditions. From wildfires to heavy rainfalls, the landscape of the west is changing, and this is a fact that we must learn how to cope with. So, how can we learn from this year’s El Niño?

Hopefully, El Niño will spur Southern California towards change in its methods of harvesting rainwater. One method of achieving this is through the restoration of its rivers, most of which are currently paved in concrete. A concrete river can’t filter water or prevent runoff, but a restored river naturally provides a buffer against flooding, runoff, and erosion, making it easier to collect rainwater. The harvesting and conservation of rainwater is crucial if Southern California’s future looks anything like recent years-- characterized by persistent drought with infrequent but intense bouts of rain. California’s lawmakers have deliberated on such projects in recent years. Hopefully, El Niño will motivate them to take action.

What can we do as individuals? First of all, enjoy the rain. But remember that we are still in the midst of drought. So continue to conserve water, educate yourself on issues related to climate change, and advocate for further change.