As hot as the world has been in the past couple of years, we may actually have had it easy because La Niña has kept the equatorial waters in the Pacific cooler than normal and helped lower temperatures around the world -- but that is expected to change this year as the warmer, El Niño weather pattern takes over in the Pacific.
Buckle your seatbelts.
As an article in Wired explains, La Niña is expected to end sometime this spring, having lasted a near-record three years, and give way to El Nino. "When it does," the article says, "the extreme weather that has rampaged across our planet in 2021 and 2022 will pale into insignificance."
A global temperature increase of 1.5°C above the 1850-1900 average is generally treated as a break point in climate change, above which major danger lurks. Wired says that in 2021 the figure was 1.2°C, "while in 2019—before the development of the latest La Niña—it was a worryingly high 1.36°C. As the heat builds again in 2023, it is perfectly possible that we will touch or even exceed 1.5°C for the first time."
The article adds: "I wouldn't be at all surprised to see the record for the highest recorded temperature—currently 54.4°C (129.9°F) in California's Death Valley—shattered. This could well happen somewhere in the Middle East or South Asia, where temperatures could climb above 55°C [131°F]. The heat could exceed the blistering 40°C [104°F] mark again in the UK, and for the first time, top 50°C [122°F] in parts of Europe."
The result would be severe droughts in many areas, slashing harvests and exacerbating food shortages at a time when the Russian invasion of Ukraine has already created concerns about grain supplies. Civil unrest could follow.
In the U.S., the article says, the most affected region would be the Southwest, where a 22-year drought already threatens "lakes and dams [that] provide water and power for millions of people in seven states, including California. The breakdown of this supply would be catastrophic for agriculture, industry and populations right across the region."
Because La Niña tends to limit hurricane development in the Atlantic, its disappearance could facilitate more tropical storms after a year that saw surprisingly few. The storms could also be more powerful than hurricanes in previous years because they will pull their energy from ever-warmer surface waters. The storms could also be wetter, because warmer air can hold more moisture. We saw what happened this year with Hurricane Ian, which gathered an enormous amount of energy and water just before making landfall in Florida.
Not all effects with be negative, of course. For instance, in my neck of the woods in northern California, La Niña tends to limit precipitation during our winter rainy season and has contributed to a withering drought that has enabled massive wildfires, so a move to El Niño could give this part of the world a break. (Even with La Niña, we've already had a major storm and expect a series of them over the next week-plus.)
In general, though, I'm afraid that my Happy New Year greeting comes with a caveat: We may well have some rough weather ahead.
Cheers,
Paul