A few miles inland from the Sea of Cortez, amid cracked earth and mesquite and sun-bleached cactus, neat rows of emerald plants are sprouting from the desert floor.
The crop is salicornia. It is nourished by seawater flowing from a man-made canal. And if you believe the American who is farming it, this incongruous swath of green has the potential to feed the world, fuel our vehicles and slow global warming.
He is Carl Hodges, a Tucson-based atmospheric physicist who has spent most of his 71 years figuring out how humans can feed themselves in places where good soil and fresh water are in short supply.
The founding director of the University of Arizona's highly regarded Environmental Research Lab, his work has attracted an eclectic band of admirers. They include heads of state, corporate chieftains and Hollywood stars, among them Martin Sheen and the late Marlon Brando.
Hodges' knack for making things grow in odd environments has been on display at the Land Pavilion in the Epcot theme park at Walt Disney World in Florida and the Biosphere 2 project in Arizona.
Here in the northern Mexican state of Sonora, he's thinking much bigger.
The Earth's ice sheets are melting fast. Scientists predict that rising seas could swallow some low-lying areas, displacing millions of people.
Hodges sees opportunity. Why not divert the flow inland to create wealth and jobs instead of catastrophe?
He wants to channel the ocean into man-made "rivers" to nourish commercial aquaculture operations, mangrove forests and crops that produce food and fuel. This greening of desert coastlines, he said, could add millions of acres of productive farmland and sequester vast quantities of carbon dioxide, the primary culprit in global warming. Hodges contends that it could also neutralize sea-level rise, in part by using exhausted freshwater aquifers as gigantic natural storage tanks for ocean water.
Analyzing recent projections of ice melt occurring in the Antarctic and Greenland, Hodges calculates that diverting the equivalent of three Mississippi Rivers inland would do the trick. He figures that would require 50 good-sized seawater farms that could be built within a decade if the world gets cracking.
"The only way we can stop [sea-level rise] is if people believe we can," said Hodges, whose outsize intellect is exceeded only by his self-assurance. "This is the big idea" that humanity has been waiting for, he believes.
With his trademark floppy hat, an iPhone wired perpetually to his head and a propensity to assign environmental reading homework to complete strangers, Hodges might be dismissed by some as an eccentric who has spent too much time in the Mexican sun.
"When I first met Carl, I thought he was a philosopher," said actor Sheen, a longtime friend.
Still, experts including Dennis Bushnell, chief scientist at NASA's Langley Research Center, say seawater agriculture could prove to be an important weapon in the fight against climate change.
Hodges has already built such a farm in Africa. Political upheaval there shut much of it down in 2003. That's why he's determined to construct a showcase project in North America to demonstrate what's possible.
All he needs now is $35 million. That's where salicornia comes in.
A so-called halophyte, or salt-loving plant, the briny succulent thrives in hellish heat and pitiful soil on little more than a regular dousing of ocean water. Several countries are experimenting with salicornia and other saltwater-tolerant species as sources of food. Known in some restaurants as sea asparagus, salicornia can be eaten fresh or steamed, squeezed into cooking oil or ground into high-protein meal.
Hodges, who now heads the nonprofit Seawater Foundation, plugged salicornia for years as the plant to help end world hunger. Do-gooders applauded. The private sector yawned.
Then oil prices exploded. Hodges saw his shot to lift his fleshy, leafless shrub from obscurity.
That's because salicornia has another nifty quality: It can be converted into biofuel. And, unlike grain-based ethanol, it doesn't need rain or prime farmland, and it doesn't distort global food markets. NASA has estimated that halophytes planted over an area the size of the Sahara Desert could supply more than 90% of the world's energy needs.
Last year, Hodges formed a for-profit company called Global Seawater Inc. to produce salicornia biofuel in liquid and solid versions. He lugs samples of it around in a suitcase like some environmental traveling salesman.
The enterprise recently planted 1,000 acres of salicornia here in rural Sonora, where Hodges has been doing preparatory research for decades. That crop will provide seed for a major venture planned 50 miles north in the coastal city of Bahia de Kino. Global Seawater is attempting to lease or buy 12,000 acres there for what it envisions will be the world's largest seawater farm.