Re: Getting too hot for Amazonian CDR and transpiration

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rob de laet

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Dec 11, 2025, 9:20:06 PM (4 days ago) Dec 11

to Carbon Dioxide Removal, Tom Goreau, healthy-planet-action-coalition, EcoRestoration Alliance, Anastassia Makarieva

Hi Tom,

thank you. Can't see the article behind the payroll, but from a hydrological cooling standpoint 2100 is very optimistic as this study on “hot droughts” in the central Amazon shows how narrow the safety margin of the forest already is: once soil moisture drops past a critical threshold, transpiration collapses, tree mortality spikes and the system is pushed toward dieback under a projected “hypertropical” climate ''by 2100''. But by focusing mainly on climate scenarios and stand-level mortality, it actually understates the risk from the full biotic pump feedback of deforestation, fire, and moisture recycling breakdown, which means that from a risk management perspective the Amazon is already deep inside the tipping zone and there is a real chance that the dieback will occur in years, rather than decades with unfatomable fires, stretching for hundreds kilometers and more. The spikes of global temperatures in 2023 and 2024 are in large parts connected to the droughts in the Amazon and Congo, but still not recognized as such by mainstream climate science. Current slow and incremental measures to protect this vital planetary organ are completely irrational: we are playing with fire. Our proposal to “pay everyone in the forest” through the ARARA platform is precisely a basin-scale, finance-backed mechanism designed to stop this madness: channeling large, predictable flows of capital to Indigenous peoples, smallholders, and local enterprises to protect remaining forest, restore degraded land into high-evapotranspiration vegetation that produces food and restores the water cycles to keep the biotic pump functioning and with that the largest cooling and rehydrating organ of or living planet. Who will embrace our solution at the scale and speed needed? Where is the will of humanity to not kill its future within the next decades?

Best,

Rob de Laet

Project Lead Cooling the Climate

Member of the EcoRestoration Alliance

Fellow of Global Evergreening Alliance

Fellow fo the Schumacher Institute

Planetary Solvency Taskforce

Co-founder of Senang Eco Services

WhatsApp: +55 71 992617846

On Friday, 12 December 2025 at 00:26:34 CET, Tom Goreau <gor...@globalcoral.org> wrote:

Article

Published: 10 December 2025

Hot droughts in the Amazon provide a window to a future hypertropical climate

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Nature (2025)

Abstract

Tropical forests represent the warmest and wettest of Earth’s biomes, but with continued anthropogenic warming, they will be pushed to climate states with no current analogue^1,2. Droughts in the tropics are already becoming more intense as they occur at successively higher temperatures^3,4,5. Here we synthesize multiple datasets to assess the effects of hot droughts on a central Amazon forest. First, a more than 30-year record of annually resolved forest demographic data from a selective logging experiment showed higher tree mortality during intense droughts, particularly among fast-growing pioneer species with low wood density. Second, analysis of ecophysiological field measurements from the 2015 and 2023 El Niño droughts identified a soil moisture threshold beyond which transpiration rates rapidly declined. As rainless days beyond this threshold continued, drought conditions intensified, increasing the potential for tree mortality from hydraulic failure and carbon starvation. Third, analyses from the Coupled Model Intercomparison Project Phase 6 demonstrated that under high-emission scenarios, a large area of tropical forest will shift to a hotter ‘hypertropical’ climate by 2100. Last, under a hypertropical climate, temperature and moisture conditions during typical dry season months will more frequently exceed identified drought mortality thresholds, elevating the risk of forest dieback. Present-day hot droughts are harbingers of this emerging climate, offering a window for studying tropical forests under expected extreme future conditions^6,7,8.