Imagine you are the Pacific Ocean. Trade winds blow west along the equator, taking warm water from South America into Asia—much like how products are exported to different countries. As the water leaves, cold water takes its place as it rises from above, a process called upwelling, while the exchange happens.

Now, imagine the “demand” increasing for warm water to be “exported” to Asia. You work overtime to send as much water to Asia, but there are unintended side effects that happen as a result.

This “overtime” is known as a La Niña. According to the National Ocean Service, it is a weather phenomenon that happens for around 9 to 12 months, but there are times where it can last for years. They happen every 2 to 7 years on an irregular schedule. A La Niña can have a global impact on weather, wildfires, ecosystems, and even economies. During a La Niña, the trade winds buffet the Pacific Ocean as they push warm water to Asia. Due to more water being pushed to Asia, upwelling increases near the coasts of the Americas as a result. However, there is more to what meets than the eye from this increase in upwelling.

Jet streams—powerful air currents circulating above the atmospheres of the northern and southern hemispheres—are whisked to the north by the cold water. According to Met Office, these jet streams are responsible for changing the wind and pressure at a specific level in the atmosphere, affecting areas of high and low pressure and shaping the weather. As a result, the lands of the southern United States are parched by droughts and a heavy downpour of water rains from the skies and floods the northern United States and Canada. The winter temperatures are warmer than normal in the south and colder in the north.

“It doesn’t mean for sure, 100% it’s going to be dry, but it does tilt the odds towards dry,” deputy of the Climate Prediction Center Mike Halpert says. “If you had been wet for a while now, drier than average wouldn’t matter—but it becomes very significant this year because of the drought that’s already in place. Another dry winter is certainly not going to be good news for California.”

Hurricane seasons become more severe during a La Niña event. Cold waters become more nutrient-rich and have favorable living conditions to house more marine life and cold water species like squids and salmon.

This year, California is expected to enter its third year in a “Triple Dip” La Niña. The affected area has weather conditions similar to a northern hemisphere winter since September 2020.

“It is exceptional to have three years consecutive years with a La Niña event,” Secretary General of the World Meterological Organization Petteri Taalas says. “Its cooling influence is temporarily slowing down the rise in global temperatures—but it will not halt or reverse the long-term warming trend.”

This Triple Dip is expected to occur through the rest of 2022 to early 2023.

There is a 91% chance of La Niña conditions during the months of September through November and a 54% chance during the months of January through March, according to the National Weather Service. This fall, there will be less rain and drier conditions for most of the United States.

With the La Niña happening right now, the relationship between it and climate change is a topic of interest among many.

“Human induced climate change amplifies the impacts of naturally occurring events like La Niña and is increasingly influencing our weather patterns,” Petteri Taalas says, “in particular through more intense heat and drought—and the associated risk of wildfires— as well as record breaking deluges of rainfall and flooding.”

Some effects of climate change in California include rising sea levels leading to coastal flooding and erosion, saltwater contamination, damage to agriculture, and loss of ecosystems and habitats. Concerning agriculture, severe droughts and floods can reduce crop yields and increase food prices, affecting those living in rural and urban areas.

“Like most scientists, I am concerned about the rate at which this (climate change) is now occurring,” chemistry teacher Ms. Kalmer says. “California, in my lifetime, has definitely been getting warmer. This leads to less snowpack, water availability, and disastrous wildfires.”

The Triple Dip La Niña marks the first time in the 21st century where this has happened. While this may be an impressive feat, it is also intensifying the effects of climate change. What’s being done to mitigate the effects? What’s stopping us from doing so?