Pacific heat pulse is temporary, but scientists warn that its climate impacts are not. The 2024 El Niño in the Tropical Pacific, combined with human-caused warming, dried out vast tracts of the Amazon region, crushing livelihoods and displacing people, and also flipped some forests to release more carbon dioxide than they absorb and store, a “regime shift” in the Amazon carbon cycle. Credit: Luis Acosta/AFP via Getty Images The Pacific Ocean is a giant climate cauldron, with a powerful heat engine that affects storms, fisheries, and rainfall patterns half a world away, and scientists are watching closely to see if it’s about to boil over. Their projections suggest the tropical Pacific is simmering toward a strong El Niño , the warm phase of an ocean-atmosphere cycle that can intensify and shift those impacts.…