The air along the Purus River in Brazil's Amazonas state held moisture you could feel against the roof of your mouth, warm and particulate, saturated with the transpiration of ten thousand plant species exhaling water vapor into channels so dense with green the canopy closed overhead and sealed the corridor beneath into something closer to liquid than atmosphere, where the sound of water moving through roots and over submerged wood was constant and low, a frequency you stopped hearing after the first hour and noticed only when it stopped, and sweat could not evaporate and skin stayed slick from morning through the equatorial night, and the river dolphins surfaced pink with capillary heat, their blowholes opening into air that was nearly water itself, and the tambaqui and pirarucu moved at depths where temperature held steady and oxygen dissolved in concentrations their gills had calibrated to across millennia, and the current pressed against the hulls of passing boats with a weight you could feel through wood and through the bones of the hand gripping the tiller. In September 2024, the Purus measured 7.5 meters at Beruri, 2.2 meters lower than any level in four decades of record. The exposed banks released a mineral smell that mixed with the rot of stranded fish and the sweetness of vegetation dying in direct sun where it had never felt direct sun. The Madeira, the Amazon's largest tributary, dropped to 79 centimeters at Porto Velho, and along its exposed bed the stones held heat through the night the way river stones are not supposed to, radiating warmth into air thick with smoke, a layer of soot that covered nearly sixty percent of Brazil. In Lake Tefé, water temperatures reached 32°C, four degrees past what the resident species could survive, and over 200 river dolphins died alongside thousands of fish, their bodies collecting in shallows too warm to hold the oxygen that flesh requires.
In the village of Nossa Senhora do Livramento, a community leader pointed to white marks nearly four meters overhead on the trees where the waterline used to reach. Boats listed on mud that cracked and paled in sun the river had never let through. The dry season runs a month longer than it did in the 1970s. The Madeira has lost nearly ten percent of its flow each decade. Over sixty percent of Amazonian communities depend on rivers rather than roads. When the water drops, 1,359 Indigenous villages face isolation. No boats. No medicine. Women in labor, waiting for water that does not rise. The Amazon has warmed 0.27°C per decade for forty years.
A study in Science Advances published March 6 found that the mechanism has changed. Heat-driven drought, where heat itself initiates the drying, covered 2.5 percent of Earth's land in the 1980s. The land-atmosphere system worked one way. Heat arrives first. Pulls moisture from soil. Dry soil cannot cool the air. The air heats. Rain weakens or fails. The feedback locks.
Threshold: 14.3°C global average. Crossed around 2000.
The rate after 2000: eight times faster. The authors call it a regime shift. Possibly irreversible. Jennifer Francis of the Woodwell Climate Research Center called the timing "eerily coincident" with rapid Arctic warming and sea-ice loss.
Lytton, British Columbia. June 2021. Nearly 50°C. The town burned.
Northeastern BC. Fires from 2023 smouldered underground through two winters. Permafrost exposed.
September 2025. 85 percent of Canada abnormally dry. Dawson Creek: 150 days of stored water.
Alaska. 2.5 times the acreage burned after 2000 than the twenty years before. One-third of Arctic tundra now a carbon source.
Usteq. Ground collapse.
February 2026. A 275-hectare fire northwest of Calgary.
February.
East Africa. The Deyr rains failed.
Somalia. National emergency. November 2025.
Bay and Bakool. Harvests below ten percent.
Ethiopia. Seeds did not germinate.
Central Africa. Among the sharpest increases since 2000.
Livestock eating plastic.
6.5 million hungry.
2.5 million children.
Heat. Soil.
Heat.
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El Niño building again: European forecast models show unusually strong agreement on a potentially very strong El Niño event later this year, and the last event of comparable magnitude in 1997-98 may have triggered the very regime shift the Kim et al. study identifies.
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Arctic tundra flipping: New research from Woodwell Climate's Permafrost Pathways found that one-third of Arctic tundra has shifted from carbon sink to carbon source, accelerated by the same fire-permafrost feedback loop intensifying across Alaska and northern Canada.
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Somalia's hunger doubling: Oxfam reported in early March that the number of people facing hunger in Somalia has nearly doubled since early 2025, reaching 6.5 million, with one in three people expected to be in crisis-level hunger by March 2026.
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Amazonian fish biodiversity threat: Researchers found that the record 2023-2024 droughts triggered multiple simultaneous threats to Amazonian fish species, including warming waters, habitat loss, and compromised reproduction in species like pirarucu and tambaqui whose thermal tolerances evolved for a river system that no longer exists.