Ocean Heatwave Fuels Land's Extreme Temperatures

An enormous marine heatwave off the US west coast is intensifying and is expected to expand in the coming months. This phenomenon is accompanied by the projected formation of El Niño in the tropical Pacific, creating a mélange of oceanic and atmospheric conditions that could influence global weather patterns. Scientists are re-examining assumptions about the acceleration of climate crisis effects due to this complex interplay.

The marine heatwave has already contributed to shockingly extreme temperatures across the United States, with March land temperatures soaring significantly above seasonal norms. This event saw hundreds of US cities set new all-time temperature records for March. Low snowpack across the western US is also a concern, exacerbating drought conditions and increasing the risk of a severe wildfire season.

Beyond terrestrial impacts, scientists are alarmed by the heatwave's effects on marine life, including whales, seabirds, and seals, and their dependent food webs. The situation mirrors the "the Blob" marine heatwave of 2015, which led to devastating impacts on salmon populations and resulted in the deaths of an estimated million seabirds. Subtropical species are shifting their ranges northward in search of cooler waters.

With a greater than two in three chance of a strong or extreme El Niño later this year, the combination of marine heatwaves and El Niño events is increasingly viewed as a symptom of human-caused climate crisis. These events are occurring more frequently and intensely, making it difficult for ecosystems to recover.