Dennis Garrity and Robert Tulip chat with Metta Spencer about Climate and Agriculture
rob...@rtulip.net
Project Save The World’s Metta Spencer just hosted this conversation with HPAC chair Dr Dennis Garrity and myself, mainly on the need to cool the Earth to protect agriculture.
Summary is below. Link to watch is at https://projectsavetheworld.substack.com/p/climate-and-agriculture
Metta got me to start the chat with a short performance on the didgeridoo, have a watch.
Regards
Robert Tulip
From: Project Save the World from Project Save the World's Substack <projectsa...@substack.com>
Sent: Friday, 20 February 2026 2:25 PM
To: rob...@rtulip.net
Subject: About 'Climate and Agriculture'
Dennis Garrity's and Robert Tulip's professional careers addressed development problems. Now the planet's heat threatens to reduce food production, so they promote quicker solutions.
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
About 'Climate and Agriculture'
Dennis Garrity's and Robert Tulip's professional careers addressed development problems. Now the planet's heat threatens to reduce food production, so they promote quicker solutions.
Feb 20 ∙
It is a dark, freezing night in Toronto where Metta Spencer sits, listening to the static hiss of freezing rain against her window. But thousands of miles away, the sun is blazing. In the Philippines, it is a bright morning for systems agronomist Dennis Garrity, and in Australia, Robert Tulip is starting his day. Connected by the digital threads of a Zoom call, these three distinct voices have gathered to discuss a topic that bridges the gap between ancient tradition and futuristic science: the survival of global agriculture in a warming world.
The conversation begins not with data points or crop yields, but with a low, resonant drone that seems to vibrate from the earth itself. Robert Tulip, a policy expert formerly with the Australian Agency for International Development (AusAID), holds up a five-foot-long hollow log—a didgeridoo. It is an instrument born of nature, created when termites hollow out hardwood trees in Arnhem Land, Northern Australia. With a mouthpiece made of beeswax and charcoal, Tulip demonstrates the ancient technique of circular breathing, producing a continuous sound that has anchored Indigenous Australian spirituality for 60,000 years.
“It’s deeply connected to the earth,” Tulip explains. It is a fitting opening ceremony for a discussion that will soon pivot to how humanity might need to sever its natural reliance on the current climate to save that very earth.
The Agronomist’s Epiphany
To understand the stakes of the future, Dennis Garrity takes the group back to the past. Garrity, a distinguished researcher who spent decades leading the World Agroforestry Center in Nairobi, traces his career back to a single, terrifying moment in an Ohio high school library in the late 1960s. He had stumbled upon a book titled Famine 1975!
“It was written by two agronomists who were trying to come to grips with the fact that in Asia, population and demand for food was growing much faster than food supply,” Garrity recalls. The prediction was dire: countries like India, China, and the Philippines were on the brink of mass starvation.
Dennis Garrity
But the famine of 1975 never happened. Instead, the world witnessed the “Green Revolution.” Garrity describes how he backpacked through Asia as a young man, eventually landing at the International Rice Research Institute (IRRI) in the Philippines—the very “mother of the Green Revolution.” There, scientists developed rice varieties that tripled yield potentials. “I was absolutely overwhelmed by the opportunity,” Garrity says. He watched as nations that were once dependent on U.S. food aid became self-sufficient exporters within a decade.
For Garrity, this was proof that agricultural science could solve humanitarian crises on a massive scale. It launched him into a career of “evergreening”—integrating trees with crops to restore soil health for hundreds of thousands of smallholder farmers across Africa and Asia.
The Wizard and the Prophet
However, the easy victories of the Green Revolution are over. Robert Tulip introduces a philosophical framework to the conversation, citing Charles Mann’s book The Wizard and the Prophet. The “Wizard” is Norman Borlaug, the father of the Green Revolution, representing the belief that technology and innovation can overcome ecological limits. The “Prophet” is William Vogt, an early environmentalist who argued that humanity must cut back and conserve to survive.
“Two great leaders of the last century who represent two poles of what’s needed,” Tulip notes. But as the climate warms, the tension between these two philosophies is reaching 
a breaking point. The agricultural research community is facing a terrifying realization: heat is becoming a hard constraint.
“Unless we do something about heat, then all of the research that they’ve been doing faces great risk of failure and famine,” Tulip warns.
Robert Tulip
This is where the conversation shifts from the soil to the stratosphere. We are facing a future of “multiple breadbasket failures,” where simultaneous heat domes, droughts, and floods across major agricultural regions could spike food prices and devastate the world’s poor. The pests are moving north, the tropics are becoming too hot for field labor, and the crops are reaching their thermal limits.
The Volcano in the Room
The solution proposed by Garrity and Tulip is one that makes many uncomfortable: Solar Geoengineering, specifically sunlight reflection.
The concept involves spraying aerosols into the upper stratosphere to reflect a tiny fraction of sunlight back into space, effectively turning down the global thermostat. To the uninitiated, it sounds like science fiction—or worse, playing God.
“We are actually engineering the climate of the planet to reverse the effects of the previous engineering that has been destroying the climate,” Garrity argues, reframing the narrative from interference to stewardship.
Critics often recoil at the idea, fearing that blocking the sun will kill the very crops Garrity has spent his life protecting. But Garrity is quick to debunk this myth. “The amount of sunlight which we’re talking of reducing is extremely small. It’s less than 1%,” he explains. Furthermore, the scattering of light by these aerosols could actually increase photosynthesis by diffusing light to the lower leaves of the plant canopy.
Garrity speaks with the authority of someone who has seen the effects firsthand. He lives near Mount Pinatubo in the Philippines. When the volcano erupted in 1991, it was a natural experiment in solar geoengineering.
“I almost lost my life during that experience,” Garrity admits, recalling a harrowing escape from the “Pompeii-like” ash fall. But while the eruption was a local disaster, it was a global lesson. The aerosols ejected by Pinatubo cooled the entire planet by about half a degree Celsius, without collapsing global agriculture. It proved the science works.
The Political Gridlock
If the science is sound and the need is urgent, why isn’t the world embracing sunlight reflection? Tulip attributes it to a paralyzed public discourse. The debate on climate change is polarized between those who deny the problem exists and those who believe rapid decarbonization is the only solution.
“When they look at what we’re saying about sunlight reflection, they seem to automatically think that we’re on the other side from them,” Tulip says. Environmentalists suspect it’s a ploy by the fossil fuel industry to delay emissions cuts, while climate skeptics view it as part of a “climate scam.”
In reality, Tulip and Garrity argue, it is neither. It is an emergency brake. Decarbonization is essential, but it is slow. The carbon already in the atmosphere will continue to warm the planet for decades. Sunlight reflection may be the only method that can lower temperatures quickly enough to save the agricultural systems upon which billions depend.
Beyond the Field
The conversation concludes by looking even further ahead. If the fields become too hot, where will the food come from? Garrity, ever the scientist, is open to radical alternatives. He speaks enthusiastically about the rise of alternative proteins—lab-grown meats and fermentation-based proteins produced from air, water, and yeast.
“The demand for meat keeps going up at a very rapid rate,” Garrity notes. The resulting increase in ruminant animals (cattle, sheep, goats) produces methane, further heating the planet. By decoupling protein production from pastureland, humanity could reduce agricultural pressure on the environment, allowing land to be rewilded.
A New Stewardship
From the ancient resonance of the didgeridoo to the high-tech intervention of stratospheric aerosols, the conversation between Spencer, Garrity, and Tulip spans the full breadth of the human relationship with nature.
The message is clear: The passive appreciation of nature is no longer enough. To save the world’s food supply, humanity may have to embrace the role of the “Wizard” more fully than ever before, becoming active stewards of the atmosphere itself. As Garrity points out, we have already engineered the climate by accident through pollution; the moral imperative now may be to engineer it on purpose for survival.
© 2026 Project Save the World
548 Market Street PMB 72296, San Francisco, CA 94104
Unsubscribe
