Houston claimed the No. 1 spot among the 50 most visited in the U.S. with the lowest carbon footprint. Sean Pavone/Getty Images

People looking to travel to a sustainable city probably don’t have Texas spots at the top of their lists. Images of oil, cars, and blasting air conditioners spring up. The Texas power grid, no one need remind us, is barely hanging on.

But Texas blew other states away for lowest carbon footprint per capita, landing Houston at the top of the list compiled by travel blog Park Sleep Fly. Austin followed (No. 3), then San Antonio (No. 4) and Dallas (No. 9). Only Florida appeared twice in the top 10, and none matched Texas with four cities.

Among the 50 most visited in the U.S., those with the lowest carbon footprint are:

1. Houston
2. Los Angeles
3. Austin
4. San Antonio
5. Tampa, Florida
6. Salt Lake City
7. Phoenix
8. Miami
9. Dallas
10. Portland, Oregon

Houston is not exactly a green place, with less-than-ideal utilization of public transportation. It and Dallas tied for third place among least sustainable cities in the same report.

“Public transit isn’t the most popular mode of transportation in Houston, but it does exist,” an online publication called TripSavvy drably admits. The city takes credit for employing “nearly one third” of the nation’s oil and gas extraction workers.

On the renewable side, however, Houston claims more than 100 solar energy companies, and at least half of its corporate research and development centers pursue “energy technology and innovation.” And its huge population spreads the load, leaving only 14.6 metric tons of carbon dioxide per resident — the same as Los Angeles. Big cities seem to have an advantage in this rating system.

Austin is just behind Houston at 15 metric tons per capita, neck-and-neck with San Antonio at 15.2. These two cities have smaller populations to distribute their total footprint, but are generally seen as eco-friendly. Austin got a big head start in 1991 with the introduction of the Austin Energy Green Building program — the first of its kind in the whole country — which created an evaluation system for individual building sustainability that’s still in use. Dallas' carbon footprint is the largest of the Texas cities in the ranking, at 16.5 metric tons per capita.

As such a multifaceted issue (especially tied up in economic concerns), sustainability is hard to pin down from city to city. The multiplicity of this list is yet another indicator that Texas as a whole is a much more nuanced place than many people think.

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This article originally ran on CultureMap.

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Houston scientists develop breakthrough AI-driven process to design, decode genetic circuits

biotech breakthrough

Researchers at Rice University have developed an innovative process that uses artificial intelligence to better understand complex genetic circuits.

A study, published in the journal Nature, shows how the new technique, known as “Combining Long- and Short-range Sequencing to Investigate Genetic Complexity,” or CLASSIC, can generate and test millions of DNA designs at the same time, which, according to Rice.

The work was led by Rice’s Caleb Bashor, deputy director for the Rice Synthetic Biology Institute and member of the Ken Kennedy Institute. Bashor has been working with Kshitij Rai and Ronan O’Connell, co-first authors on the study, on the CLASSIC for over four years, according to a news release.

“Our work is the first demonstration that you can use AI for designing these circuits,” Bashor said in the release.

Genetic circuits program cells to perform specific functions. Finding the circuit that matches a desired function or performance "can be like looking for a needle in a haystack," Bashor explained. This work looked to find a solution to this long-standing challenge in synthetic biology.

First, the team developed a library of proof-of-concept genetic circuits. It then pooled the circuits and inserted them into human cells. Next, they used long-read and short-read DNA sequencing to create "a master map" that linked each circuit to how it performed.

The data was then used to train AI and machine learning models to analyze circuits and make accurate predictions for how untested circuits might perform.

“We end up with measurements for a lot of the possible designs but not all of them, and that is where building the (machine learning) model comes in,” O’Connell explained in the release. “We use the data to train a model that can understand this landscape and predict things we were not able to generate data on.”

Ultimately, the researchers believe the circuit characterization and AI-driven understanding can speed up synthetic biology, lead to faster development of biotechnology and potentially support more cell-based therapy breakthroughs by shedding new light on how gene circuits behave, according to Rice.

“We think AI/ML-driven design is the future of synthetic biology,” Bashor added in the release. “As we collect more data using CLASSIC, we can train more complex models to make predictions for how to design even more sophisticated and useful cellular biotechnology.”

The team at Rice also worked with Pankaj Mehta’s group in the department of physics at Boston University and Todd Treangen’s group in Rice’s computer science department. Research was supported by the National Institutes of Health, Office of Naval Research, the Robert J. Kleberg Jr. and Helen C. Kleberg Foundation, the American Heart Association, National Library of Medicine, the National Science Foundation, Rice’s Ken Kennedy Institute and the Rice Institute of Synthetic Biology.

James Collins, a biomedical engineer at MIT who helped establish synthetic biology as a field, added that CLASSIC is a new, defining milestone.

“Twenty-five years ago, those early circuits showed that we could program living cells, but they were built one at a time, each requiring months of tuning,” said Collins, who was one of the inventors of the toggle switch. “Bashor and colleagues have now delivered a transformative leap: CLASSIC brings high-throughput engineering to gene circuit design, allowing exploration of combinatorial spaces that were previously out of reach. Their platform doesn’t just accelerate the design-build-test-learn cycle; it redefines its scale, marking a new era of data-driven synthetic biology.”

Axiom Space wins NASA contract for fifth private mission, lands $350M in financing

ready for takeoff

Editor's note: This story has been updated to include information about Axiom's recent funding.

Axiom Space, a Houston-based space infrastructure company that’s developing the first commercial space station, has forged a deal with NASA to carry out the fifth civilian-staffed mission to the International Space Station.

Axiom Mission 5 is scheduled to launch in January 2027, at the earliest, from NASA’s Kennedy Space Center in Florida. The crew of non-government astronauts is expected to spend up to 14 days docked at the International Space Station (ISS). Various science and research activities will take place during the mission.

The crew for the upcoming mission hasn’t been announced. Previous Axiom missions were commanded by retired NASA astronauts Michael López-Alegría, the company’s chief astronaut, and Peggy Whitson, the company’s vice president of human spaceflight.

“All four previous [Axiom] missions have expanded the global community of space explorers, diversifying scientific investigations in microgravity, and providing significant insight that is benefiting the development of our next-generation space station, Axiom Station,” Jonathan Cirtain, president and CEO of Axiom, said in a news release.

As part of Axiom’s new contract with NASA, Voyager Technologies will provide payload services for Axiom’s fifth mission. Voyager, a defense, national security, and space technology company, recently announced a four-year, $24.5 million contract with NASA’s Johnson Space Center in Houston to provide mission management services for the ISS.

Axiom also announced today, Feb. 12, that it has secured $350 million in a financing round led by Type One Ventures and Qatar Investment Authority.

The company shared in a news release that the funding will support the continued development of its commercial space station, known as Axiom Station, and the production of its Axiom Extravehicular Mobility Unit (AxEMU) under its NASA spacesuit contract.

NASA awarded Axiom a contract in January 2020 to create Axiom Station. The project is currently underway.

"Axiom Space isn’t just building hardware, it’s building the backbone of humanity’s next era in orbit," Tarek Waked, Founding General Partner at Type One Ventures, said in a news release. "Their rare combination of execution, government trust, and global partnerships positions them as the clear successor-architect for life after the ISS. This is how the United States continues to lead in space.”

Houston edtech company closes oversubscribed $3M seed round

fresh funding

Houston-based edtech company TrueLeap Inc. closed an oversubscribed seed round last month.

The $3.3 million round was led by Joe Swinbank Family Limited Partnership, a venture capital firm based in Houston. Gamper Ventures, another Houston firm, also participated with additional strategic partners.

TrueLeap reports that the funding will support the large-scale rollout of its "edge AI, integrated learning systems and last-mile broadband across underserved communities."

“The last mile is where most digital transformation efforts break down,” Sandip Bordoloi, CEO and president of TrueLeap, said in a news release. “TrueLeap was built to operate where bandwidth is limited, power is unreliable, and institutions need real systems—not pilots. This round allows us to scale infrastructure that actually works on the ground.”

True Leap works to address the digital divide in education through its AI-powered education, workforce systems and digital services that are designed for underserved and low-connectivity communities.

The company has created infrastructure in Africa, India and rural America. Just this week, it announced an agreement with the City of Kinshasa in the Democratic Republic of Congo to deploy a digital twin platform for its public education system that will allow provincial leaders to manage enrollment, staffing, infrastructure and performance with live data.

“What sets TrueLeap apart is their infrastructure mindset,” Joe Swinbank, General Partner at Joe Swinbank Family Limited Partnership, added in the news release. “They are building the physical and digital rails that allow entire ecosystems to function. The convergence of edge compute, connectivity, and services makes this a compelling global infrastructure opportunity.”

TrueLeap was founded by Bordoloi and Sunny Zhang and developed out of Born Global Ventures, a Houston venture studio focused on advancing immigrant-founded technology. It closed an oversubscribed pre-seed in 2024.