Just like El Nino, the weather impact can be global. In Indonesia and parts of Australia, La Niña can bring flooding rains, affecting wheat, sugar, palm oil and rubber crops as well as coal and iron ore mining.
In Argentina and the U.S. Plains, La Niña can trigger drought, hurting the Argentine corn and soy crops and the main U.S. hard red winter wheat crop.
La Niña tends to lead to wind patterns that favor the formation of more hurricanes in the Atlantic and fewer in the eastern Pacific, potentially meaning a greater threat to U.S. Gulf oil and gas assets and cities in Florida, the Gulf Coast and eastern seaboard.
Major recent La Niña events occurred in 1973-76, 1988-89 and 2010-12.
Heat from the tropics drives the global climate by fuelling ocean and atmospheric patterns that shift the warmth around the globe. Warm tropical waters fuel evaporation and add moisture to the atmosphere needed for clouds to form.
The rising air also drives atmospheric circulation patterns that help shift the moisture and warmth around to other parts of the globe. So disrupting this pattern can alter the climate elsewhere.
Scientists say climate change might also be adding an extra kick to La Niña and El Niño because warmer oceans add more fuel to storms and weather patterns.
(Sources: NOAA, Australian Bureau of Meteorology, National Centre for Atmospheric Research, Reuters)
(Editing by Ed Davies)