SARGENT — Herff Cornelius and his family have ranched in the Texas Gulf Coast for five generations, four in Matagorda County, but he is struggling to keep the tradition going.

Growing up, he was one of nine siblings. Even though he was the only boy, his sisters did as much on the ranch as he did in the kitchen. He and his wife Nancy had two children, but both went off to college and can’t be as involved.

Now Cornelius has a chance to get a helping hand in maintaining his ranch from an unlikely source: A new initiative aimed at protecting coastal lands and combating global warming.

Scientists stress the urgency of keeping the planet from getting warmer, citing the need to cut greenhouse-gas emissions, and land can play an important role in doing just that. Natural ecosystems such as Texas coastal marshes, prairies and bottomland hardwood forests absorb carbon dioxide from the atmosphere and incorporate it into their roots. That carbon then becomes part of the soil and can remain there for a long time.

Texas has more than 8 million acres of undeveloped coastal lands, but 80% is privately owned, so finding a way to work with landowners is a must.

“Traditional conservation organization methods such as buying land for preservation or doing conservation easements have sort of reached their audience,” said Azure Bevington, a coastal ecologist. “Part of it is that we need something new to move even farther ahead.”

After years of trial and error, a group of local environmentalists created the nonprofit Texas Coastal Exchange to help protect natural lands. The project was officially launched this month.

Under the nonprofit’s model, in exchange for not selling or developing his land for 10 years, Cornelius would get a payment from people or companies that have made a donation equivalent to their “carbon footprint” — say, the emissions caused by driving a car. The amount of the grant is based on the size of his property, the ecosystem and how much carbon dioxide it’s able to store.

“By necessity in Texas, we found a pathway that works for private landowners and works for conservation and is a pathway that, as far as I know, no one else has discovered,” said Jim Blackburn, an environmental law professor at Rice University.

Carbon dioxide occurs naturally in the atmosphere, but it is also released by burning fossil fuels such as gasoline, propane, oil and coal, and the level of it in the atmosphere is at the highest point in human history.

Houston has one of the highest per capita greenhouse-gas emissions in the country, in part due to motor vehicles, city officials have said. Recently, officials unveiled the first draft of a climate action plan with the goal of becoming carbon-neutral by 2050.

One challenge is that Texas’ coastal lands are being lost to erosion, rising sea level and development. And when natural land is lost, it not only prevents future carbon dioxide sequestration, but releases what was already stored.

Blackburn and his team believe they can help counter climate change by creating a market where landowners can make money off storing carbon dioxide. So far they have one donor and one grantee, but are currently talking with several others who are interested, including Cornelius.

“It’s a payment to a private landowner to basically grow a crop,” Blackburn said, “but the crop is ecology.”

For Cornelius, finding ways to work with landowners makes sense.

“Farmers and ranchers were probably the first environmentalists. If you don’t take care of your land, it won’t take care of you,” he said during a recent morning out on his ranch near the Gulf of Mexico, where he takes his prime-beef cattle to graze part of the year.

About 70% of the 3,500 acres that Cornelius owns is coastal marshland. The cows are particularly fond of the salt-cord grasses, he said, the more tender the better, and of what he calls “salt Bermuda,” which grows closer to the water.

Even though he can’t imagine doing anything else, tending to the ranch is tiring. Every day, they have to make the rounds — making sure the cows have fresh water, figuring out wind direction to see if grass can be safely burned and mending fences.

“Now there are less people who grew up on farms and ranches, so they weren’t trained as kids, they weren’t taught how to work around livestock or equipment,” said the 60-year-old rancher.

“We try to hire day cowboys, but the good ones are always busy,” he said. “You have to book a month in advance, and if it’s raining, you lose your day.”

There’s not enough money to support more than one family, he said. “You work a lot but don’t have any cash to show for it, it’s all invested in the land, cattle or tractors.”

Something like the Texas Coastal Exchange could help him stay in business and get rewarded for work he’s already doing, he said.

He is also considering a conservation easement agreement that would prohibit future development on the land indefinitely.

Under the new initiative, he could do both and continue using the land for grazing and hunting waterfowl.

The carbon market may never be robust enough to be a farmer’s or rancher’s sole source of income, Blackburn said. “But by combining a cattle operation, carbon farming, and leasing his land for hunting purposes, a rancher could tap several income resources that allow his ranch to remain healthy and profitable.”

Near the Cornelius property, colorful waterfront houses already dot the landscape. And it’s not hard to see how his vast land, with shrubs and grasses near the ocean, could be prime for development.

For Wes Good, president of Kirksey Architecture, becoming the first donor to the exchange was a way to support a local effort and work toward becoming a carbon-neutral company.

The Houston-based firm already plants trees and buys 100% renewable energy, but it was looking for something innovative to add to its portfolio.

“We are all living on this planet. Every day in architecture and construction, we are helping to develop and build and in doing so, you should be responsible to do that in the best and most sustainable way possible,” he said. “We owe it to society to try to make the environments we live in, the environments we design, and the environments that are natural as sustainable and as great a place as they can be.”

The idea of donating to a local effort — and to something they could see and touch — was appealing, he said.

The company donated to store 770 metric tons of carbon dioxide on 386 acres of marshlands owned by the Galveston Bay Foundation.

The way the system works, the donor pays $20 to support the storage of one metric ton, with $17 going to the landowner in the form of a grant and the other $3 being used to support the educational outreach and administration of the organization. Donations are tax deductible.

“Someone asked ‘Well the marshlands are already there and already doing the job, why do you have to pay money to say you are helping it do its job? Without companies investing, there’s no guarantee the marshlands will stay,” Good said. “It’s only protected as long as there’s someone there to protect it, and it costs money to have that program. That’s why we do it.”

The objective of the exchange, Blackburn said, is to allow donors to financially support the carbon dioxide storage that is already occurring and to provide incentives to grow it by protecting more natural ecosystems.

The exchange sees itself as a pollution removal service where carbon dioxide is stored and one that can lead to “massive land conversion over time,” he said.

The way existing voluntary carbon dioxide offset programs normally work is that someone makes a donation to offset some of their emissions and the funds are used to pay for projects to plant trees or develop new sources of renewable energy. “Conservation on its own doesn’t help reduce the carbon footprint of any activity or business,” wrote Pep Canadell, executive director of the Australia-based Global Carbon Project, a scientific group that produces global carbon budgets.

Blackburn and his colleague Elizabeth Winston Jones spent the past decade looking at precisely those models, governmental and commercial, but in the end concluded they were too onerous for the average Texas coastal landowner. They knew they’d need buy-in from the landowners.

So they compromised. Instead of the 40 or so years some of these programs require that land be preserved, they dropped it to 10 years, the shortest duration they felt they could go.

They made it completely voluntary, and because it is not a commercial endeavor, it doesn’t meet some of the more rigorous international standards. Instead, Bevington, the group’s chief scientist, will base her estimates on carbon-dioxide storage potential based on peer-reviewed studies and the type of ecosystem.

They will only accept donations equivalent to the amount of carbon dioxide that can be stored in the lands of participating property owners and commit to full transparency, she said, so the donor can see exactly where the money is going.

Finding an economic incentive for landowners to manage ecosystems makes sense, wrote David Moore, an associate professor in the School of Natural Resources and the Environment at the University of Arizona. It “is an important part of the solution to climate change and environmental degradation.” Because of the complexity of natural ecosystems, some monitoring will be required to ensure these efforts are working.

“The strongest programs will always be the ones with multiple benefits,” Canadell wrote, adding that he considers the initiative to be promising.

The overarching goal, Bevington said, “is to protect coastal lands which have many benefits beside carbon storage,” including serving as a habitat for fisheries and migrating birds and reducing storm surge and provide flood holding capacity.

The exchange’s initial goal is to enroll 2 million acres of undeveloped coastal lands in Texas. Its hope is that this model is replicated elsewhere in the country.

“This is one approach,” Blackburn said. “There will be other variations, pure commercial applications, nonprofits that spring up in other cities.”

And if it can work in Texas, the group figures, it can work anywhere.