From Washington State on down through California prolonged drought has prompted governments to institute emergency water conservation measures and hastily launch initiatives to assure the long-term security of water supplies. An unusual, very large and persistent “blob” of high pressure air off the U.S. West Coast has been identified and proposed as the principal causal agent.
Drought of historic proportions extends well south of the U.S.-Mexico border, however, and it’s threatening agriculture, hydroelectric power production and the lives and livelihoods of millions in Central America. Last year, the worst drought in 40 years put the lives of an estimated 2 million people living in what’s known as the region’s “Dry Corridor” at grave risk. Nearly all of them were smallholder farmers and their families that rely on subsistence farming for their livelihoods.
Drought is exacting its toll elsewhere in Central America as well. In the midst of this year’s rainy season, Panama has been experiencing a heat wave and precedent-setting lack of rainfall. Precipitation levels for the past two months have reached historic lows, according to a July 10 news report. As well as threatening crop production, the drought is affecting operations and maritime traffic through the Panama Canal, which is reported to account for a quarter or more of national GDP.
A perfect storm?
The occurrence of El Niño/ENSO conditions in the central-eastern Pacific is one big factor contributing to the extreme dry conditions. A warming climate is an underlying driver, setting a backdrop that climate scientists say leads to higher probabilities of extreme weather events and greater variability in weather patterns.
The onset of El Niño has heightened expectations that rains will arrive and alleviate drought conditions across the western U.S. That may be a forlorn hope, however. In its March 2015 announcement of the onset of El Niño, NOAA’s Emily Becker points out that past data reveals that El Niño has only been associated with above average spring rainfall in California in three of 10 instances.
Along with El Niño, the ongoing rise and accumulation of carbon dioxide (CO2) and greenhouse gases (GHGs) from the burning of fossil fuels and other human activities is an underlying factor in the record lack of rainfall and heat wave experienced in Panama during the past two months, Carlos Centella, who is in charge of weather forecasting and preparedness for electric utility ENSA, told reporters.
“Along with El Niño, the ongoing rise and accumulation of carbon dioxide (CO2) and greenhouse gases (GHGs) from the burning of fossil fuels and other human activities is an underlying factor in the record lack of rainfall and heat wave experienced in Panama during the past two months.”
With rainfall in Panama 50 percent below normal nationwide and 80 percent below average in some provinces the same situation is set to repeating itself this year. Centella said Panamanians can expect unusually high temperatures – above 40 degrees Celsius (104ºF) – and abnormally low rainfall as the rainy season progresses.
Centella warned that the onset of El Niño conditions that began taking shape late last year could persist anywhere from two to seven years. Panama lost between $7 million and $8 million worth of agricultural production over the course of the last El Niño event, which occurred in 2009-2010, he recounted.
During May, average rainfall in Panama was the lowest in 50 years, according to Carlos Varga, VP of water, energy and agriculture for the Panama Canal Authority. June’s rainfall was the lowest in 102 years.
The lack of rain has lowered water levels in the Chagres River, which flows into Gatun and Alajela lakes, two of the principal reservoirs and water sources for the Panama Canal, as well as Panama City, the city of Colón and the communities of San Miguelito and La Chorrera to the Panama Canal.
Estimating there’s a 90 percent probability El Niño will persist into September both Panamanian organizations continue to monitor weather and climate conditions and precipitation closely. They’re providing regular reports to government officials that will enable them to craft action plans in the event water supplies are threatened further.
*Image credits: 1) DAN Church Aid; 2), 3) NOAA