For the first time in seven years, El Niño is here, setting the stage for a likely surge in global temperatures and more extreme weather, according to the United Nations鈥� weather agency. 

The World Meteorological Organization (WMO) made the official declaration on Tuesday while forecasting a 90 per cent chance the El Niño event will continue during the second half of 2023 and maintain a moderate strength or higher. 

鈥淭he onset of El Niño will greatly increase the likelihood of breaking temperature records and triggering more extreme heat in many parts of the world and in the ocean,鈥� WMO secretary-general Petteri Taalas .

鈥淭he declaration of an El Niño by WMO is the signal to governments around the world to mobilize preparations to limit the impacts on our health, our ecosystems and our economies.鈥� 

WHAT IS EL NIÑO?

Scientists have been expecting .

The naturally occurring climate pattern appears every two to seven years, on average, and typically lasts nine to 12 months. 

El Niño works in tandem with La Niña, which is also a naturally occurring climate pattern. El Niño is associated with the warming of ocean surface temperatures in the central and eastern tropical Pacific Ocean. In contrast, La Niña refers to the large-scale cooling of ocean surface temperatures in the same region, coupled with a reversal of the overlying atmospheric conditions.

In many areas around the world, La Niña cold episodes produce the opposite effects to El Niño, which is usually associated with a period of cooler temperatures. A La Niña episode may, but does not always, follow El Niño.

NEXT FIVE YEARS EXPECTED TO BE WARMEST ON RECORD

Scientists are expecting a temporary burst of heat from El Niño to supercharge human-caused global warming to new heights. 

In May, the WMO said there is a 98 per cent chance that at least one of the next five years, as well as .

Currently, 2016 is the warmest year on record because of the 鈥渄ouble whammy鈥� of an exceptionally strong El Niño and human-induced global warming, according to the UN agency.

The organization also said there is a two-out-of-three chance the phenomenon will temporarily push the average global temperature to more than 1.5 degrees Celsius above pre-industrial levels between 2023 and 2027.   

That mark is critical because of the 2015 Paris agreement, through  above pre-industrial levels.

The agreement refers to long-term global warming over many years.

Although the El Niño phenomenon is expected to only temporarily increase the global temperature to more than 1.5 C above pre-industrial levels, Chris Hewitt, director of climate services at WMO, said there is reason for concern. 

鈥淚t is yet another wake up call, or an early warning, that we are not yet going in the right direction to limit the warming to within the targets set in Paris in 2015 designed to substantially reduce the impacts of climate change鈥� Hewitt said in the release.

HOW WILL CANADA BE AFFECTED?

Warmer waters during an El Niño event can cause the Pacific jet stream to move south of its neutral position. As a result, areas in the northern U.S. and Canada become dryer and warmer than usual. 

Historically, Canada is mostly affected by El Niño during winter and spring. As a result, these seasons typically become milder than normal in western, northwestern and central Canada during the phenomenon, .

Generally, El Niño does not significantly impact eastern Canada, including the Maritimes, but it may reduce tropical cyclone activity in the Atlantic Ocean.