When Strong El Niño Mixes with Climate Change

California has struggled with periodic droughts; its most recent was the 5-year event of 2012-2016. Droughts are a recurring feature of its climate.

But when tropical storm Hilary hit on 21 August from Mexico, bringing floods to Los Angeles and San Diego, the area received its entire year’s average amount of rain in a single day. It flooded the state’s arid valleys, breaking its rainfall record.

NOAA‘s historical hurricane track data shows that tropical storms and hurricanes the likes of Hilary are rare in the Southern part of California; the last one was still in 1997 due to the cool ocean waters and currents as well as prevailing trade winds that blow from east to west in this area which makes it hard for storms and hurricanes to maintain its strength.

The Economist reports that the rare tropical storm (Hilary) coming in August coincided with El Niño. This weather pattern temporarily increases global temperatures while redistributing heat and moisture worldwide.

Meteorologists predicted a strong El Niño that began in June this year, a climate pattern that occurs every two to seven years. A strong El Niño combined with climate change effects could bring devastating results.

For example, there is a good chance that this year will be the hottest, but 2024 will be even hotter, and the temperature could reach 1.4°C above pre-industrial levels. The article says that countries must start preparing for the consequences of El Niño and climate change now.

El Niño will bring damaging floods in tropical regions. In other areas, droughts will develop, straining food supplies and spreading diseases.

Its last cycle was in 2014-16, bringing catastrophic results in some countries. Droughts in South Africa led to its lowest food production in 20 years. Indonesia suffers from its worst wildfires, and warmer and wetter weather in South America has led to its worst Zika virus outbreak in 65 years.

As serious as these impacts are, there are ways to prepare for them before they come, and the cyclical nature of the El Niño helps. Improvements in forecasting also help predict storms much earlier than in previous years and could assist in prioritising funds, for example, to improve infrastructure resilience.

The article notes that some agencies are using better forecasts to plan ahead of time. The International Federation of the Red Cross and Red Crescent runs anticipatory programmes in 17 countries, aiming to spend a quarter of its disaster relief funding in advance by 2025.

And the World Health Organisation started working with the World Meteorological Organisation to predict where best to allocate medical supplies and personnel successfully.

Our previous blog about El Niño and its links to Climate Change explains more.