For the past few years, ocean temperatures have steadily increased, much to the surprise of scientists, despite the Pacific being firmly under the influence of the cooling La Nina phenomenon. Scientists announced in January that the oceans had been at record-warm temperatures for the past four years. Then, climatologists noticed that the global sea surface temperature reached a new high in the middle of March.
The extraordinary tendency scares scientists about what may be in store for them, especially given that predictions indicate El Nio may begin to develop this summer, bringing with it effects like high heat, hazardous tropical cyclones, and a serious threat to delicate coral reefs.
The tropical Pacific Ocean experiences La Nia and El Nio on a regular basis; La Nia is characterized by cooler-than-average water temperatures, whilst El Nio delivers warmer-than-average temperatures. Both have a significant impact on weather around the world. Moreover, the transition to El Nio will very certainly be accompanied by an increase in global temperatures.
According to climate scientist Daniel Swain of the University of California, Los Angeles, the tropical Pacific is already undergoing a “dramatic transition” from La Nia to El Nio.
He claimed that during the coming several months, “El Nio rapid development” was being signaled by both the atmosphere and the water at the same time.
Even with La Nia’s cooling influence, the past three years have been among the warmest on record. Professor Adam Scaife, director of long-range forecasting at the UK Met Office, told CNN, “We’re now turning it off.”
The upcoming El Nio’s strength is unknown; some predictions indicate it could be super-strength, while others say it will be more moderate. But it is evident that El Nio will bring about catastrophic and unprecedented effects for many parts of the planet when combined with human-caused global warming.
Here are the climatic and weather extremes to be aware of.
For the first time, the earth might warm by more than 1.5 degrees.
For the first time, El Nio may cause global warming to surpass 1.5 degrees Celsius above pre-industrial levels in the middle to late 1800s.
Governments committed to keeping global warming far below 2 degrees, ideally 1.5 degrees, relative to pre-industrial temperatures as part of the Paris Climate Accord. A major tipping point, according to scientists, is 1.5 degrees of warming, after which the likelihood of extreme flooding, drought, wildfires, and food shortages may significantly rise.
According to Scaife, even if only briefly, a strong El Nio might cause the globe to reach that point.
According to Josef Ludescher, a senior scientist at the Potsdam Institute for Climate Impact Research, “2024 will likely be the warmest year on record globally.” The current hottest year on record was 2016, which came after a very powerful El Nio.
As long as people continue to burn fossil fuels and create pollution that warms the planet, there has already been an approximate 1.2 degree warming of the planet. Nevertheless, temperatures have risen to alarming heights after three years of cooling caused by La Nina.
In 2022, temperatures in Europe reached above 40 degrees Celsius (104 degrees Fahrenheit), and Pakistan and India also had a scorching heatwave, with certain areas of those countries reaching over 49 degrees Celsius (120 Fahrenheit).
Ultimately, Scaife added, it “doesn’t really matter” if the 1.5-degree threshold is reached or just barely missed. The truly important point is that for the first time in human history, that value is within grasp.
Whatever the precise degree of heating El Nio brings, Scaife noted that certain of its effects, such as severe temperatures, are quite likely to be unprecedented. We are presently experiencing an increasing level of global warming as a result of each El Nio.
There may be more rain in the West that will end the drought.
In recent months, rain and snow have deluged California. El Nio may result in a worsening of that.
As record-breaking snowfall in the Sierra and torrential rain saturated the rest of the state, NOAA stated in March that California already faced potential flood dangers this spring.
El Nio would certainly cause above-normal rainfall across a large portion of the state, increasing the likelihood of flooding, landslides, and coastline erosion, experts said CNN.
The Colorado River Basin could even receive “significant drought relief,” according to Brad Rippey, a meteorologist with the US Department of Agriculture.
For the continental United States, La Nia has historically been a “drought creator,” but El Nio is a “drought breaker,” according to Rippey. But the precise region of dryness, or lack thereof, changes greatly from event to event.
The Colorado River, which supplies water for drinking, agriculture, and energy to some 40 million people throughout the Southwest, has been hampered by overuse and a drought brought on by climate change. In the past two years, the federal government has imposed unprecedented forced water cuts due to the severeness of the water situation.
A stronger and extended Pacific jet stream, which are fast-moving air currents in the upper atmosphere that affect day-to-day weather, could “elevate odds for atmospheric river-type events for the West Coast” while also causing more intense precipitation in the South, according to Jon Gottschalck, head forecaster at NOAA’s Climate Prediction Center.
Heat, fire, and drought elsewhere
El Nio may intensify wildfires, intense heat waves, and droughts in other parts of the world.
Drought and excessive heat are threats to South Africa, India, and countries close to the West Pacific, such as Indonesia, Australia, and Pacific island states like Vanuatu and Fiji.
El Nio is predicted to bring considerably drier, hotter weather to Australia, which is still suffering from significant flooding, especially in the eastern parts of the nation. According to a representative for Australia’s Department of Meteorology, 18 of the 27 El Nio years since 1900 have resulted in significant winter and spring drought.
Fears of a particularly severe bushfire season have grown as a result of recent rains, since increased vegetation growth may supply fuel for fires when the climate becomes dryer and hotter.
El Nio could weaken the monsoon, which brings the rain it depends on to replenish aquifers and develop crops, therefore India is also preparing for its effects.
According to Raghu Murtugudde, an Earth systems scientist at the University of Maryland, the monsoon is most commonly impacted when there is a switch from a La Nia winter, which we recently saw, to an El Nio summer, which is anticipated to be the summer of 2023.
He told CNN that “the whole [gap in monsoon rainfall] can be as high as 15%.”
India, which is currently experiencing abnormally early heatwaves, could also experience a rise in temperatures as a result of El Nio. Kieren Hunt, a research scientist at the University of Reading in England, described it as a “compound threat” since heat waves and El Nio frequently lead the monsoon to arrive later than usual.
He said that prolonged dry periods will “place a great pressure on water security.”
Stronger cyclones are fueled by a warmer Pacific Ocean.
Gottschalck predicts that changes in tropical cyclone activity will be one of the first signs of El Nio.
El Nio, in contrast to La Nia, tends to lessen the frequency of Atlantic hurricanes, but has the reverse impact in the Pacific, where warm waters can foster stronger typhoons.
According to Gottschalck, “tropical cyclones can frequently originate further west in the basin and remain stronger longer, increasing the potential damage to Hawaii.” This entails “increased likelihood of landfall and remotely triggered consequences, including bigger and longer-lasting waves, intense rainfall, and more.”
Other parts of the Pacific are also experiencing exceptionally high precipitation and flooding in the deserts, according to Swain, who noted that models indicate “extremely warm waters” off the coast of Peru. “It is a classic symptom of a powerful El Nio event.”
Peru may be much more at risk of more flooding as El Nio develops and intensifies later in the year. To avert the worst effects, the government has already committed to spending more than $1 billion on climate and weather-related measures.
There could be catastrophic bleaching on coral reefs.
El Nio causes the ocean to warm, and coral reefs don’t like warmer water.
Corals will spit up the algae that is present in their tissue and gives them their color and the majority of their energy when they become too hot. Corals become white as a result, a condition known as bleaching. Bleaching increases their danger of malnutrition and mortality, although they can recover if temperatures gradually cool.
Between 2014 and 2017, every significant reef on the planet experienced a particularly devastating period of coral bleaching. During a particularly severe El Nio that began in 2015, Australia’s Great Barrier Reef had nearly 30% of its corals perish in a record-breaking marine heatwave in 2016.
Scientists are growing more concerned about the effects on coral that has just not had enough time to recover as several mass bleaching events have occurred afterwards, and El Nio is predicted to arrive soon.
According to Peter Houk, a professor at the University of Guam Marine Laboratory who researches coral in Micronesia, “what’s being prophesied here is quite dangerous.” The intensity of each one increases slightly over time.
According to Houk, not every coral will necessarily be impacted by El Nio. There are constantly other natural climate trends at work, and every El Nio is unique. But when it happens, he added, “it’s brutal.”
El Nio, whenever it occurs, will provide an opportunity to learn more about how coral responds and where pockets of resistance may arise, according to Houk. He just needs it to wait a little bit longer. “We hope the forecasts are wrong so we can buy a few more years for the corals to recover,” says the author.
Antarctic ice is melting more.
El Nio may make the already precarious situation of the Antarctic ice worse.
Fear that the continent, which had had years of ups and downs, would now be on a severe downhill trend arose earlier this year when ice levels on the continent plunged to record-breaking lows for the second time in two years.
Recent studies have established a correlation between the strength and frequency of El Nio episodes and the rate of Antarctic ice melt, suggesting that El Nio may help speed up this process.
Wenju Cai, head research scientist at CSIRO, Australia’s national science agency, told CNN that models that predict a bigger increase in El Nio consistently result in a faster melting of the ice sheets than those that predict a lesser shift in El Nio.
Because Antarctica’s ice contains such an alarmingly large amount of water, scientists are keeping a tight eye on it. The Antarctic ice sheet has enough water in it to increase the world sea level by 230 feet even though it is doubtful that it would totally melt (70 meters).
El Nio episodes have varying effects on Antarctica in the short term, Cai noted, with spikes and decreases in various regions. But when viewed as a whole, he claimed, the trend is obvious: “a decrease in overall sea ice.”