El Niño and La Niña: Local and global effects

The document describes the El Niño-Southern Oscillation (ENSO) as a natural climate pattern consisting of warm (El Niño), cold (La Niña), and neutral phases driven by sea surface temperatures and pressures in the tropical Pacific. It details how these phases disrupt atmospheric circulation, affecting global precipitation and temperature. Specifically, La Niña is associated with wetter conditions in Australia and Indonesia and warmer, drier winters in the southern U.S., while El Niño is linked to drought in Australia and Indonesia and cooler, wetter winters in the southern U.S. The text emphasizes that while ENSO can nudge global temperatures, it does not mask the long-term warming trend caused by carbon pollution; for instance, 2022 remained the sixth hottest year on record despite a persistent La Niña. Historical data from the 2015-2016 El Niño event highlights severe consequences, including forest fires in Indonesia, flooding in Peru, and an estimated 60 million people impacted by extremes across Africa, Latin America, the Caribbean, and the Asia-Pacific region.

• The El Niño-Southern Oscillation (ENSO) consists of three phases: Neutral, El Niño (warm), and La Niña (cold), which occur every two to seven years based on sea surface temperatures and surface pressures in the tropical Pacific.
• ENSO phases significantly alter global weather; La Niña typically brings wet conditions and flooding risks to Australia and Indonesia, whereas El Niño brings drought- and wildfire-prone conditions to those same regions.
• In the United States, La Niña is associated with warm and dry winters in the south and wetter, cooler conditions in Alaska and the Pacific Northwest, while El Niño typically brings cool and wet winters to the southern U.S. and mild winters to Northwest Canada and Alaska.
• La Niña generally increases hurricane activity in the Atlantic by reducing wind shear, while El Niño has the opposite effect.
• Short-term cooling from La Niña has not offset human-caused global warming; 2022 was the planet's sixth hottest year despite being the third consecutive La Niña winter.
• The 2015-2016 El Niño event caused widespread forest fires in Indonesia and catastrophic flooding in Peru, with the World Health Organization estimating that 60 million people across the Asia-Pacific, Africa, Latin America, and the Caribbean were affected by rainfall and heat extremes.
• Analysis of data since 1950 indicates that ENSO has a delayed effect on annual global mean temperatures, with the average ENSO value from September through August showing the closest relationship to the January-December temperature.

APA

Climate Central (2023). El Niño and La Niña: Local and global effects. https://www.climatecentral.org/climate-matters/local-and-global-effects-of-el-nino-and-la-nina-2023

Chicago

Climate Central. El Niño and La Niña: Local and global effects. 2023. https://www.climatecentral.org/climate-matters/local-and-global-effects-of-el-nino-and-la-nina-2023.

Wikipedia

{{cite report |author=Climate Central |title=El Niño and La Niña: Local and global effects |date=8 February 2023 |url=https://www.climatecentral.org/climate-matters/local-and-global-effects-of-el-nino-and-la-nina-2023 |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{climatecentral2023nio, author = {{Climate Central}}, title = {{El Niño and La Niña: Local and global effects}}, institution = {Climate Central}, year = {2023}, month = feb, url = {https://www.climatecentral.org/climate-matters/local-and-global-effects-of-el-nino-and-la-nina-2023}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }