Climate Today
Earth is rapidly moving toward conditions that threaten human habitability. Urgency is fading, and complacency is rising. Ocean corals have already passed their tipping point and are likely to disappear. The 1.5°C target is out of reach. The 2°C target is out of reach. Some experts now warn that even 2.5°C may be unattainable.
Climate Trace reports more than 60 gigatons of CO₂e emissions in 2025, an increase of roughly 0.4% over 2024—despite massive global efforts to reduce greenhouse gases. To reach netzero by 2050, emissions must fall at least 6% per year.
Reducing emissions is extraordinarily difficult. We should applaud all who are working to protect our climate and our planet.
The Biotic Pump
Reducing greenhouse gases alone will not prevent environmental catastrophe if we continue destroying natural ecosystems. The central thesis of biotic pump theory is that greenhouse gases warm the planet, but water movement and waterstate changes drive climate stability. (1)
Consider the Amazon Rainforest, often called the “heart and lungs” of the world. Moisture flows through the forest in “flying rivers.” As water vapor rises and forms clouds, it creates lowpressure air currents near the ground. These currents pull moist air inland from higherpressure regions such as the Atlantic Ocean. This process increases rainfall and sustains the rainforest. This mechanism is known as the biotic pump.
When water vapor condenses into liquid, roughly 22,000 cubic meters of vapor collapse into one grammolecule of water. This implosive condensation drives air upward. Combined with the recycling of evapotranspired water, the forest irrigates itself deep into the continent.
The latent heat released during condensation—equivalent to 300,000 atomic bomb explosions per year (2) across the Amazon—helps export up to 70% of incoming solar heat back into space. This is Earth’s most important cooling mechanism, roughly 200 times more powerful than the cooling provided by carbon sequestration in biomass.
If the Amazon collapses into savanna or desert, the loss of this cooling could push large regions of the planet beyond survivable wetbulb temperatures.
Minimum Conditions for a Biotic Pump
Tree plantations and young forests generally cannot generate a functioning biotic pump. At least 10 square kilometers of continuous oldgrowth forest with 100% canopy cover are required. Oldgrowth forests contain many trees with diameters of 10 inches or more. Although only about 1% of trees reach this size, they store roughly 50% of all forest carbon.
Rain falling on Brazil’s east coast typically evaporates, condenses, and falls again five to seven times as it travels westward across the continent. When it reaches the Andes, rainfall shifts south into Peru, Bolivia, and then Argentina. A broken biotic pump—caused by deforestation—will likely trigger rapid savannafication in Peru and Bolivia. (3)
Consequences of Amazon Deforestation
A 2025 Nature Communications study found that tree loss in western Brazil increased 27% from the previous year and that 75% of the region’s rainfall decline is directly linked to deforestation. Some areas have already become net greenhouse gas producers. As one researcher put it: “If you chop down a tree, it reduces moisture going into the atmosphere.” This creates a dangerous feedback loop.
In Brazil’s Caatinga region, one farmer lamented, “When you plant something, it dies.” A map published by The Guardian (12/28/25) shows accelerating desertification and expanding savanna zones in Peru and Bolivia.
As deforestation spreads, droughts intensify, lakes dry up, aquatic life collapses, and rivers stop flowing—threatening every community that depends on them. Hydropower, which supplies much of South America’s electricity, will decline.
Meanwhile, China’s partnership with Peru to build a fully automated port at Chancay is accelerating infrastructure development across Brazil—highways, waterways, airports, ports, and railways—to export timber, soy, and beef. This expansion risks turning the Amazon into a massive greenhouse gas emitter. (4)
A Proposal for San Diego
Biotic pumps can operate at local and regional scales, cooling landscapes and restoring water cycles. Protecting and expanding forests is equivalent to strengthening water security. Forests are uniquely capable of maintaining stable regional hydrology, as shown in Milan Milan’s work on Mediterranean water cycles. (5)
A weakened Amazon will even affect San Diego, which receives 60% of its water from the Colorado River.
- If the Amazon reaches its tipping point, Los Angeles—and potentially all of California—could lose much of its rainmaking capacity.
- Atmospheric rivers originating over the Amazon influence California’s rainfall.
- A deforested Amazon could reduce the Sierra Nevada snowpack by 50%, threatening water supplies for cities and agriculture across the western United States.
- As Medvigy et al. (2013) note, changes in Sierra Nevada snowpack could have “serious consequences for the food supply of the United States.”
The Colorado River Research Group’s 2025 report, Dancing with Deadpool, warns that precipitation in the basin has already declined 7% this century due to human activity.
A Biotic Pump Plan for San Diego County
Using AI (Copilot), I outlined a strategy to develop a biotic pump in San Diego—an approach that can be adapted anywhere. The main challenge is finding sufficient space in a heavily urbanized region.
Key steps include:
- Select suitable locations: prioritize degraded ecosystems, use native vegetation, reforest where possible, and restore wetlands.
- Integrate urban forestry and greening: expand canopy cover in cities.
- Collaborate with local agencies and communities.
- Partner with universities for monitoring and adaptive management.
- Launch public education and awareness campaigns.
The most promising locations are the San Luis Rey watershed, the San Diego River watershed, the Tijuana River Valley and the Carlsbad watershed.
Long-Term Climate Resilience Benefits
Investing in biotic pump systems can help San Diego County:
- Reduce heat stress in vulnerable urban neighborhoods.
- Improve water security by increasing rainfall and groundwater recharge.
- Support biodiversity by strengthening habitat corridors.
- Improve climate through carbon sequestration in restored ecosystems.
A Call to Action
If you live in San Diego, let’s form a task force to develop a local biotic pump. Everyone is welcome. If you live elsewhere, gather partners and begin planning your own. Our future depends on the actions we take now.
References
- Biotic Pump of Atmospheric Moisture as driver of the hydrological cycle on land, A.M. Makarieva and V.G. Gorshkov, 2007, Hydrology and Earth System Sciences
- Cooling the Climate, Peter Bunyard and Rob DeLaet, Ethics International Press UK Ltd., 2024
- A. M. Makarieva, Why we need forests: their role in climate dynamics, rain and the biotic pump, Great Simplification podcast with Nate Hagens, 10 Sep 2025
- Georgina Gustin, A Massive, Chinese-Backed Port in Peru Could Push the Amazon Rainforest Over the Edge. Inside Climate News, 1 Dec 2025
- Movie: Old Growth Forests – Nature’s Biotic Water Pump by New England Forests (on YouTube)