El Niños cause trillions in lost economic growth: New study

DAMAGE from El Niño-related extreme weather — in crop losses, flooding, wildfires and civil unrest — can cost tens of billions of dollars in direct impacts over a period of months or a year.

New research suggests that the real cost is much higher — in the trillions — because conventional accounting fails to recognise “persistent” shortfalls in gross domestic product that unspool over several years and are harder to identify.

The paper, by Dartmouth Earth system scientists Christopher Callahan and Justin Mankin and published on Thursday in the journal “Science”, comes at an auspicious time. The Climate Prediction Center earlier this month raised odds beyond 90 percent that an El Niño weather pattern will form later this year.

These episodes — which occur every several years — can bring everything from hot and dry weather to Australia, wildfires to Indonesia, rain to parched East Africa, a lighter Atlantic hurricane season, winter blizzards in the US Northeast, to mortal heat to coral reefs.

Climate shocks permanently impact growth

With the world 1.2C hotter than it was before industrialisation, El Niño now practically guarantees record heat, and the World Meteorological Organisation gives a 98 percent chance one of the next five years will be the hottest recorded.

El Niño — technically a warmer phase of the eastern equatorial Pacific Ocean — has become a kind of sneak preview for some extreme conditions that climate change may make commonplace in the years ahead.

Callahan and Mankin focused on a question broader than immediate, visible weather damage: How does climate variability affect economic growth? El Niño provided them with a kind of natural experiment with which to investigate it, a discrete period of change with a long tail that they could track through subsequent years of data.

The new analysis uses a model that combines economic growth and climate variability from 1960 to 2019 and compares gross domestic product (GDP) growth around the world before and after El Niño events.