On a single Sunday in August, Typhoon Dolphin turned Shanghai's streets into rivers and pushed more than one million people from their homes. Across the same week, wildfires tore through pine forests in France and Greece, floods killed over a hundred people in India's Assam state, and Canadian smoke drifted so thickly across the Atlantic seaboard that New York's skyline disappeared behind an orange haze. These events are not coincidental. Scientists say the current El Niño is on course to become the strongest in 150 years — by what some researchers describe as a "mind-blowing margin" — and its worst effects have not yet arrived.

The gravest concern sits over South America. Climatologists are warning that El Niño will reach its peak intensity between October and December, precisely the period when the Amazon's rivers fall to their lowest levels and its undergrowth becomes most susceptible to fire. The timing matters because the Amazon is not merely a regional feature: it generates rainfall that irrigates crops as far away as Argentina and regulates temperature patterns across the entire tropical belt. A severe drought, compounded by a warming atmosphere already heated by fossil-fuel emissions, could push large sections of the forest past a tipping point from which recovery would take centuries.

The double pressure on the Amazon — long-term human-driven climate disruption layered beneath a record El Niño — is precisely what forest scientists have been modelling as a worst-case scenario for decades. Western Europe has already recorded its hottest June and July in recorded history. Three-quarters of England entered official drought conditions. South Korea and Japan registered record heat simultaneously.