At the end of last year, the Panama Canal had a problem: too much water.  Torrential rains had swollen its main water source, the artificial Lake Gatun, beyond capacity, forcing the canal authority to open the floodgates to evacuate the excess out into the Atlantic.  But in a twist of meteorological fate, amplified by climate change, within three months the opposite was true: a severe El Niiio weather phenomenon struck and the canal began imposing cargo restrictions to cope with what turned into the worst drought in its 115-year history.  “We had no rain for nearly five-and-a-half months,” Carlos Vargas, the canal authority’s executive vice-president of environment, water and energy told the Financial Times. “Usually the dry season lasts four months, but this was off the charts.”

As water levels in Lake Gatun sank as much as eight feet, five successive reductions in the weight of cargoes that ships could transport were imposed, costing the canal authority about $15m in lost fees, Mr Vargas added. About 40 ships transit the canal every day.  Panama is already suffering the impact of a changing climate, with rising sea levels threatening to submerge its idyllic San Blas island chain within decades. But the threat to a vital waterway that is synonymous with the country adds a new dimension.  “These extreme phenomena are here to stay,” said Gustavo Alanis, head of Cemda, a Latin American environmental group. “And with the risk implied by climate change, I think Panama should do more because its economy depends so much on the proper working of the canal.”

The canal, one of the world’s major trade arteries that links the Atlantic and Pacific oceans, underwent an expansion in 2016 that allowed it to accommodate bigger ships. But just three years later, additional upgrades in the form of a third lake are already needed if it is to navigate the extreme weather that is expected as a result of climate change.  Laurentino Cortizo, Panama’s incoming president who takes office in July, will have to decide whether to build a new lake in addition to lakes Gatun and Alajuela, which not only supply the canal but provide power and drinking water to more than half the country.