This story was originally published by The Guardian and appears here as part of the Climate Desk collaboration.
The return of the El Niño climate phenomenon later this year will cause global temperatures to rise “off the chart” and deliver unprecedented heat waves, scientists have warned.
Early forecasts suggest El Niño will return later in 2023, exacerbating extreme weather around the globe and making it “very likely” the world will exceed 1.5 C of warming. The hottest year in recorded history, 2016, was driven by a major El Niño.
It is part of a natural oscillation driven by ocean temperatures and winds in the Pacific, which switches between El Niño, its cooler counterpart La Niña, and neutral conditions. The last three years have seen an unusual run of consecutive La Niña events.
This year is already forecast to be hotter than 2022, which global datasets rank as the fifth or sixth hottest year on record. But El Niño occurs during the Northern Hemisphere winter and its heating effect takes months to be felt, meaning 2024 is much more likely to set a new global temperature record.
The greenhouse gases emitted by human activities have driven up the average global temperature by about 1.2 C to date. This has already led to catastrophic impacts around the world, from searing heat waves in the U.S. and Europe to devastating floods in Pakistan and Nigeria, harming millions of people.
“It’s very likely that the next big El Niño could take us over 1.5 C,” said Prof. Adam Scaife, the head of long-range prediction at the UK Met Office. “The probability of having the first year at 1.5 C in the next five-year period is now about 50:50.”
“We know that under climate change, the impacts of El Niño events are going to get stronger, and you have to add that to the effects of climate change itself, which is growing all the time,” he said. “You put those two things together, and we are likely to see unprecedented heat waves during the next El Niño.”
The fluctuating impacts of the El Niño-La Niña cycle could be seen in many regions of the world, Scaife said. “Science can now tell us when these things are coming months ahead. So we really do need to use it and be more prepared, from having readiness of emergency services right down to what crops to plant.”
Prof. James Hansen, at Columbia University in New York, and colleagues said recently: “We suggest that 2024 is likely to be off the chart as the warmest year on record. It is unlikely that the current La Niña will continue a fourth year. Even a little futz of an El Niño should be sufficient for record global temperature.” Declining air pollution in China, which blocks the sun, was also increasing heating, he said.
While El Niño would supercharge extreme weather, the degree of exacerbation was under debate among scientists.
Prof. Bill McGuire, at University College London, UK, said: “When [El Niño arrives], the extreme weather that has rampaged across our planet in 2021 and 2022 will pale into insignificance.” While Prof. Tim Palmer at the University of Oxford said: “The correlation between extreme weather and global mean temperature is not that strong [but] the thermodynamic effects of climate change are going to make the anomalies we get from an El Niño year just that more extreme.”
Climate modelling results issued in early January by Australia’s Bureau of Meteorology indicated the country could swing from three years of above-average rainfall to one of the hottest, driest El Niño periods on record, increasing the risk of severe heat waves, droughts and fires. In December, the US National Oceanic and Atmospheric Administration rated the odds of an El Niño forming by August-October as 66 per cent.
The scale of the likely El Niño was as yet unclear. Prof. Andy Turner, at the University of Reading, said: “Many seasonal forecast models are suggesting the arrival of moderate El Niño conditions from summer 2023.” The picture would be much clearer by June, the scientists said.
The El Niño-La Niña phenomenon is the biggest cause of year-to-year differences in weather in many regions. In La Niña years, the east-to-west Pacific trade winds are stronger, pushing warm surface waters to the west and drawing up deeper, cooler water in the east. El Niño events happen when the trade winds wane, allowing the warm waters to spread back eastwards, smothering the cooler waters and leading to a rise in global temperatures.
Nations bordering the west Pacific, including Indonesia and Australia, experience hotter and drier conditions. “You tend to get lots of droughts, lots of wildfires,” said Scaife, though China can suffer flooding in the Yangtze basin after big El Niños.
India’s monsoons and rains in southern Africa can also be suppressed. Other regions, such as East Africa and the southern U.S., both of which have suffered recent droughts, can get more rain and flooding. In South America, southern regions are wetter, but the Amazon, already approaching a dangerous tipping point, is drier.
“The effects of El Niño could also be felt as far as the Northern Hemisphere mid-latitudes, with a likelihood of wetter conditions in Spain from summer onwards and drier conditions on the eastern seaboard of the U.S. in the following winter and spring,” said Turner.
Palmer said the biggest unanswered question was whether climate change favoured more El Niño or more La Niña events: “That is crucially important for countries looking at long-term adaptation, and will need much higher-resolution climate models. That can only come about with bigger computers.”
Palmer and colleagues have called for the establishment of a $1-billion international centre for climate modelling, akin to the Large Hadron Collider that allows international particle physicists to do together what no single nation can do alone.
Comments
Establishing an international centre for climate modelling is a great idea. With permanent science staff conducting constant research, the world could expect a damning but perfectly legitimate, peer-reviewed report with testable conclusions and assumptions to be issued every few months.
It may be best to determine who would provide administration services to keep political interference from the Trumps, Bolsonaros, Putins and vested corporate and corrupt interests of the world at a minimum. The independence of scientific research must be protected as best as possible. I can't really think of any organization, individual nation or even the UN that has entirely resisted attempts to manipulate the scientific conclusions. Nonetheless, the UN still produces the IPCC reports which, though diluted by the above influences, still produces very significant results. Better still, the IEA could get involved and help get the message out, something they have pulled no punches on regarding fossil fuel production.
Adaptation strategies are now a top concern for those paying attention. They parallel policies to reduce emissions.
Whereas efficacious urbanism can reduce carbon very significantly while also increasing the well being of families, individuals, communities and businesses, there is a resistance to renovating inefficient neighbourhoods and expanding electric transit service to offer better quality and standards. Politicos need a spine stiffener to face-off with NIMBYs.
Shoshanna Saxe, associate professor in civil and mineral engineering at the University of Toronto and the Canada Research Chair in Sustainable Infrastructure, wrote an op-ed in last Saturday's Globe that succinctly described the attributes of sustainable urbanism.
" one essential feature of affordable housing has consistently been overlooked: the critical need for good, well-designed and well-maintained public space, from parks to streets to cultural centres, in support of that mission.
"Quality public space makes living in smaller homes more appealing by making it possible to live well in less space. Excellent parks and playgrounds mean that people won’t require a backyard. Good beaches and recreation centres free us from wanting a pool of our own. First-rate public transit and bike lanes diminish the need for cars and for space-sapping, expensive garages in which to park them.
"Smaller homes also drive community wide affordability. Building homes close together ... results in higher density, which brings benefits such as more customers for local stores, a larger tax base on which to sustain infrastructure like sewers, and more riders to justify frequent, reliable public transit.
"This has long been the classic trade-off of urban living: For less space at home, city dwellers get more and better shared amenities. When a lack of access to city spaces forces people to rely on private amenities, the trust in this trade-off is broken and people tend to flee. Inadequate or inaccessible public space incentivizes those who have the money to opt out and buy as much private space as possible; this further reduces the user base, which inevitably diminishes the communal space even more.
"This can lead to what the economist Kenneth Galbraith called “private affluence and public squalor,” which he diagnosed as a key ill of Western society. He urged us to object to the building of communities where people drive increasingly fancy cars on increasingly crumbling streets, or live in increasingly large homes with increasingly unreliable sewers. Instead – to riff on Mr. Galbraith’s concept – we need to aim for public affluence and private sufficiency."
https://www.theglobeandmail.com/opinion/article-if-we-really-want-affor…
I would add that Galbraith did not live on an English country estate, but in a then relatively modest London terrace house on Gordon Square, within walking distance of all amenities. His neighbour was Virginia Woolf.
Housing should also be top of the heap in climate adaptation strategies through design. The feds and provinces need to look at codifying the 'passive house' into architectural guidelines and structural and energy standards. The best ones are so energy efficient (R30 walls, R60 roofs, triple glazing ...) that they don't need central heating. The central air supply is one of the most important mechanical features in these structures. They run at low pressure and volume 24 / 7 with a constant HEPA-filtered fresh air supply coupled with a heat exchanger to recover 90+% of the heat from the outflowing air. A small electric heating coil can be added to the unit for extremely cold northern locations. The air can also be filtered with activated charcoal during our increasingly smoky summers rife with the effects of both regional and distant forest fires.
So far, not many decision makers are discussing sustainability along with affordability. Capital sticker price costs are not the only consideration. Long-term operating costs and efficiency has been a secondary thought for far too long, and are often so efficient in the latest designs that they warrant better analysis of the value for money of the initial price.