Spring in NYC is famously fickle — we have to prepare for everything from slushy snow and gloomy rain to gusty wind and even “pollen tsunamis.” Wait, pollen tsunamis? Before you consult your Farmers’ Almanac, a pollen tsunami is a significantly longer and more intense allergy season buoyed by warmer temperatures, rising carbon dioxide levels and increased air pollution. Pollen seasons have lengthened by about 20 days, while pollen concentrations have jumped by 21% over the past three decades, Dr. Clifford Bassett said, citing research from 2021. It could be a cold — or it could be allergies. It might be difficult to discern unless you see a medical professional. New Africa – stock.adobe.com Allergy sufferers already know it’s worse than ever — and it’s not over yet. Bassett said the tsunami will reach its first peak in May.…