Warming Temperatures Mean More Snowstorms Inbound, Say Experts
You thought you understood global warming? Think again. New research has shown that the potentially "historic" snowfall that struck the East Coast is but a taste of the intense weather that we could be facing as stronger and stronger La Niñas increase in frequency with climate change.
Extreme La Niña events are characterized by a cooling of water in the tropical Pacific. This change can drive a great number of unpredictable extreme weather events around the world as it alters the direction and temperatures of ocean currents - the same currents that drive precipitation and changes in air pressure.
Most notably, these events often give rise to low-pressure systems in the north, the same kind of system that led to this week's massive nor'easter along the US coastline.
And while cooling waters in the tropics sure don't sound like the climate change we've come to know and dread, climatologists have long known that severe El Niño events - characterized by eastward shifts in warming waters - usually closely precede intense La Niñas. In this way, you could almost say that the uncharacteristic extremes in the ocean caused by these events are trying to balance one another out, with one extreme correcting the other.
However, this balancing act isn't exactly fast. The last "super" El Niño-La Niña event on record, between 1997 and 1999, introduced severe droughts in the southwestern United States even while torrential rain ravaged western Pacific nations. (Scroll to read on...)
What's more, a study of corals in the Pacific Ocean revealed back in November that the ocean is priming for a spell of El Niño conditions - a natural phenomenon that occurs irregularly every two to seven years - which can be exacerbated by warming global temperatures.
It's also important to note that both these extreme weather events are driven by shifts in atmospheric winds and ocean currents - things that have become far less predictable than they once were. Last July, the World Meteorological Organization even made a move to start updating their definition of "normal weather" more frequently, as they expect weather conditions to continue to radically change in ways rarely seen before.
Then, last November, the World Bank stipulated that nations should consider "extreme weather" as the new norm when accounting for economic costs. They emphasized a need to be prepared for bigger and badder storms of all kinds, if not more frequent ones.
Now, a new study published in the journal Nature Climate Change has found that these changes have nearly doubled the likelihood of super-intense La Niñas. According to an international team of investigators, the most influential of La Niñas used to occur once in every 23 years. Now, the team is arguing that that rate has jumped to once in every 13 years.
Wenju Cai, a climate researcher at Australia's Commonwealth Scientific and Industrial Research Organisation, recently explained to Quartz that nearly 75 percent of that increased rate has to do with more frequent El Niños. However, the remaining 25 percent is a direct consequence of a warming world.
Cai and his colleagues found in their assessment of La Niña conditions that with the Maritime Continent facing higher surface temperatures than regions in the central and eastern Pacific, trade winds moving east-to-west will speed up, drawing cool water to the surface. This results in heavier rainfall in the western Pacific, and heighted hurricane conditions as far as the Caribbean and tropical Atlantic. Cool and wet low-pressure systems will also find their way to the United States, where the northern West Coast could suffer from heavy snowfall events similar to those being caused by winter storm Juno in the east.
Surprisingly, the international team's findings reflect what many widely accepted climate change models say, reinforcing the plausibility that more "super" El Niño-La Niña events are lurking in our future.
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