Forty-eight monitoring workers stopped work at 06:00 on Monday in Guyana’s upper Essequibo, hours after researchers published findings that the region’s rainforest may have crossed a climate tipping point. The workers want overdue heat allowances and guarantees that field stations will stay open; their stoppage has also thrust their measurements into a national argument over whether the forest is changing faster than officials admit.
Among them is Manuel U. Zambrano, a field technician who has spent 19 years measuring tree growth and rain in the forest belt. He joined the walkout as its elected representative, then made an unexpected demand: suspend cutting permits around the research plots, including the one held by his own family.
The study, released by the fictional Essequibo Institute of Forest Science, draws on 24 years of measurements from 18 plots. Researchers report that the observed forest area shifted from absorbing carbon to releasing an estimated 700,000 tonnes of carbon dioxide in 2025, after an unusually long dry season and a sharp rise in tree deaths.
The dry-season threshold
The team says the dry season reached 131 days in 2025, against a 94-day average in its records. Canopy water loss fell 22% from the earlier average, while annual tree mortality climbed to 17% from 6%. With fewer trees returning moisture to the air, the researchers warn, the forest may draw less rain and become still more vulnerable to drying.
The forest has started to feed the heat that is weakening it.
Karen Hattingh, lead ecologist
Hattingh said the findings point to a threshold crossed in 2025, not proof that every part of Guyana’s rainforest will now decline. But the study projects that, without a sharp reduction in clearing and fire, as much as 1.1 million hectares could shift toward dry woodland by 2040, releasing up to 140 million tonnes of carbon dioxide over the transition.
The stakes reach beyond the forest edge. Researchers say reduced moisture recycling could worsen dry spells in nearby farming districts and add carbon to the atmosphere; they describe both outcomes as risks, not certainties. Guyana’s climate minister, Tari Bello, said the report did not justify panic and that the country’s wider forests remained intact. Hattingh countered that intact cover does not mean a forest is still absorbing carbon.
A permit on the line
The researchers are urging an 18-month pause on new cutting permits in the monitored belt, rapid repairs to rain gauges and a publicly funded review of the dry-season trend. The workers’ union says it will maintain the stoppage until field teams receive a weekly heat allowance of G$14,000 (about €60) and written assurances that the gauges will not be switched off.
Zambrano said his family’s small permit covers a patch near one of the plots and that suspending it would mean giving up income. “If we keep taking timber as though the rain is guaranteed, we are betting against the measurements,” he said. His father taught him to read the forest by its creeks; the technician says one that ran year-round near his home now dries before the rains return.
The government has called a meeting with researchers, permit holders and striking workers for Tuesday in the interior town of Kuruku. The institute says its sensors will keep transmitting during the walkout, but field checks have stopped. For Hattingh, that gap matters: the forest’s next dry season begins before the dispute is likely to be settled.
