How will El Niño affect the global economy | world

A huge amount of warm water is slowly moving across the equatorial region of the Pacific Ocean towards South America.

This movement of water and heat started a weather phenomenon that will cause sharp changes in weather patterns around the world in the coming months.

Climate scientists recently announced that an El Niño weather phenomenon has already formed and will intensify towards the end of the year and through the early months of 2024.

They warn that there is a high chance that El Niño will be particularly strong this year. And if predictions are confirmed, the effects could be significant.

Scientists have already warned that with soaring carbon emissions and a strong El Niño this year, there is a 66% chance that the planet will pass the 1.5°C warming threshold in at least one year by 2027.

But the phenomenon could also deliver dangerous extreme weather patterns, such as heavy rains and flooding, to parts of the United States and other countries later this year and early next.

El Niño and La Niña are naturally occurring phenomena that change weather patterns around the world.

During El Niño, surface temperatures in the Pacific Ocean are higher than normal. And La Niña is its cooler opposite, with subpar ocean temperatures.

“We predicted that El Niño would continue into the winter [no hemisfério norte – verão no hemisfério sul] And the probability that it will become a powerful event upon reaching its peak is very high at 56%. The probability of at least a moderate event is about 84%, ”according to Emily Baker, director of the Cooperative Institute for Marine and Atmospheric Studies at the University of Miami in the United States, in the blog of the National Oceanic and Atmospheric Administration (NOAA, in English abbreviation) American.

It may reverberate for some time to come. A recent study by researchers at Dartmouth College in Hanover, New Hampshire, estimated that El Niño beginning in 2023 could cost the economy up to $3.4 trillion globally in the next five years.

The researchers also claim that after the recent strong El Niño events, in 1982-1983 and 1997-1998, US GDP was 3% lower than expected half a decade later. If an event of the same magnitude were to occur now, the estimated cost to the US economy would be $699 billion.

Notably, coastal tropical countries, such as Indonesia and Peru, experienced a 10% drop in GDP after the same phenomenon, according to the researchers. They project that global economic losses this century will add up to US$84 trillion (about R$410 trillion), with climate change increasing the frequency and strength of El Niños.

“An El Niño is not just a shock from which the economy immediately recovers,” says Justin Mankin, a professor of geography at Dartmouth College and one of the study’s authors.

“Our study shows that economic productivity after El Niño declined for much longer than just a year after the event.”

“When we talk about El Niño here in the US, it means that the kind of impacts that we will see, like floods and landslides, are not covered by insurance in most businesses and homes,” says Mankin. In California, for example, 98% of homeowners do not have flood insurance.

Other economic impacts in the US, Mankin says, could include damage to infrastructure from flooding — which would disrupt supply chains — and crop failure due to floods or droughts.

Should people in the United States prepare for a disastrous winter this year if El Niño hits?

not necessarily. El Niño can cause periods of severe weather in North America, but this is not always the case.

During El Niño, winds that normally push warmer Pacific waters farther west weaken.

This allows the hot water to return eastward and spread over a larger area of ​​the ocean.

This phenomenon increases the concentration of moisture in the air over the warmer ocean, which changes the circulation of air in the atmosphere around the world.

Under these conditions, weather in Canada and the northern United States is hotter and drier than normal, while southern states and the Gulf Coast of Mexico tend to be wetter, according to David DeWitt, director of the NOAA Weather Forecast Center.

“El Niño tends to increase the probability of above-normal precipitation for more than a third of the southern United States,” he said.

This phenomenon also reduces the number of hurricanes in the Atlantic Ocean, but it can generate more hurricanes in the Pacific Ocean, on the west coast of the United States. All of these effects depend to a large extent on the strength of the El Niño phenomenon responsible for the changes.

According to DeWitt, the southern United States is the region most likely to experience severe impacts, including heavy rains and potential flooding.

These phenomena would follow several years of drought that occurred after three consecutive La Niña years.

“It often happens [durante o El Niño] is that when the rain comes, it comes really fast,” DeWitt explains.

“This could cause landslides in California and other places where wildfires have occurred, potentially causing massive destruction.”

Landslides occur because the scorched earth retains less water, which can flow dangerously close.

Strong El Niño events in 1997-98 and 2015-16, for example, included floods and landslides in California. The 1997-98 season was also associated with other unusual extreme events in other parts of the United States, such as severe ice storms in New England (the Northeast) and deadly tornadoes in Florida.

But changes in weather patterns caused by El Niño also pose other problems. Infectious diseases, for example, may have a higher rate in areas where conditions are favorable for the spread of insects and other pest vectors.

A study of El Niño events that occurred in 2015-2016 concluded that disease outbreaks were 2.5% to 28% more intense.

In California, there has been an increase in cases of West Nile virus, which is transmitted by mosquitoes.

New Mexico, Arizona, Colorado, Utah and Texas have seen increased outbreaks of hantavirus pulmonary syndrome, which is transmitted primarily by rodents.

There has even been an increase in the number of plague cases in humans – although still few – in the western and southwestern United States.

During El Niño, much of the heat and moisture is transferred from the tropics toward the poles.

“When humidity increases at higher latitudes, it captures more thermal infrared radiation, which causes the temperature to rise,” DeWitt explains. “This is what we call the greenhouse effect.”

Even if it is temporary, a breach of the 1.5°C limit predicted by the World Meteorological Organization due to increased emissions and the El Niño phenomenon this year could lead to widespread human suffering around the world.

A recent study from the University of Exeter in the UK concluded that limiting global warming to 1.5°C in the long term could save billions of people from exposure to dangerous levels of heat (average temperature is 29°C or more).

Current policies are expected to cause the Earth’s temperature to rise by 2.7°C by the end of the century. The study authors warn that this indicator could leave two billion people exposed to dangerous levels of heat around the world.

Limiting warming to 1.5°C would mean five times fewer people living in extremely hot environments.

Reducing it will also help prevent climate migration and adverse health consequences, including pregnancy loss and impaired brain function, according to Tim Linton, director of the University of Exeter’s Global Systems Institute and one of the study’s authors.

There are concerns that if carbon emissions continue to rise, future El Niño events may push global temperatures above the 1.5°C threshold with increasing frequency.

“Every 0.1°C really counts,” Linton says. “Every 0.1°C of warming that we can avoid, by our calculations, prevents 140 million people from experiencing unprecedented levels of heat and the damage that could follow.”

“By doing so, we avert danger to hundreds of millions of people,” Linton concludes, “and that should be a huge incentive for us to work even harder to get emissions down to zero.”