Startups

Should we be growing trees in the desert to combat climate change?

Comment

Image Credits: James O'Neil (opens in a new window) / Getty Images

Reforestation is one of our best tools to fight the climate crisis. In the tropics, forests have been reported to absorb 10 million metric tons of carbon dioxide every year. A mature tree can absorb about 48 pounds of CO2 per year. In the U.S., our forests store 14% of all annual carbon dioxide emissions, according to the nonprofit American Forests. There is no path to climate-neutral without forests and trees.

Many businesses like Salesforce and Microsoft are funding the planting of trees in wildfire burn scars and agricultural lands. But the stealth-phase startup Undesert is working on a whole new frontier for reforestation.

As you can probably guess from the name, the company is focused on planting trees in deserts, specifically desert shrublands in the Alamogordo region of New Mexico. Nicholas Seet, CEO of Undesert, calls his company “climate triage” — doing something to reduce emissions now while the rest of the world catches up.

But should we be planting trees in the desert?

“There is a current debate about whether drylands are suitable for reforestation for the purpose of global climate mitigation purposes,” said Niall Hanan, professor of dryland ecology in the Plant and Environmental Sciences Department at New Mexico State University.

Seet called the shrublands “underutilized, empty space,” but Hanan stressed that these are valid ancient ecosystems with their own biodiversity, not simply degraded forests. And there’s a reason deserts don’t have trees.

“If [deserts] were suitable for trees they would probably have trees in them,” Hanan said. Trees need sun, CO2 and water to survive. Deserts drastically lack one of those ingredients, preventing most trees from growing naturally. But that’s one problem Undesert has innovated around.

Undesert has tweaked a water desalination technology so it can generate 20 liters of water per 24-hour period and can work with brine water previously too salty for reverse osmosis.

“The problem with [reverse osmosis] technology is it has a lot of waste brine that cannot be filtered anymore,” Seet said. “We can take reverse osmosis brine through our system and then you get pure water and salt.”

Undesert removed bottlenecks from a traditional solar-greenhouse desalination technology where the sun warms a salty pool vaporizing to create pure water that condenses on the roof of the greenhouse. Undesert developed a modular design to capture the water and was able to increase efficiency by five times that of pool evaporation. Instead of condensing on the roof, condensation occurs in a separate chamber cooled by tubing with circulating cool water. In this system more than 93% of the water in the saline is recovered as clean water. The entire process uses solar in a microgrid making the process low in emissions.

Undesert is working with Navajo nations to source for its desalination technology brackish groundwater that has become undrinkable due to salt concentration. The company then uses drip irrigation to supply the desalinated water to Afghan pines, the trees Undesert has decided to use in its reforestation. The company has planted 16 of these trees so far. Undesert chose the Afghan pine because it is desert hardy, requiring little water, and grows fast, tall and straight. The company also has 50 ponderosa pines under its watering system because its rooting system is well adapted to withstand drought. But even if the trees are getting a sufficient amount of water, there are other environmental factors like temperature that can hamper seedling survival.

According to Undesert, the small demonstration of trees supplied by the solar desalinated water has been operating since September 2021, and are showing healthy development. The area has intense solar energy and available underground saline water. And the Alamogordo region where the demonstration is located is adjacent to the Sacramento Ranger District that has forests of Douglas fir and ponderosa pine and had many more before they were removed for train tracks and maintenance. All these factors give Undesert the confidence that their trees will be a success.

But then there is the scalability. Having an entire irrigation system for a large-scale forest isn’t feasible. And using brackish groundwater might work in New Mexico, but Hanan noted that most deserts aren’t near oceans and don’t have easily accessible groundwater. Cost, labor and maintenance will also quickly add up. Even just the trees can end up costing $1 million per square mile, even if each seedling costs as little as $10, according to Hanan. Most desert inhabitants across the globe do not have access to these types of funds.

And just sourcing seedlings is already a huge problem for reforestation efforts.

“Even getting 400 for the first hectare would likely be difficult,” Hanan wrote in an email. “It is unlikely that the southwest (or even the western US) tree nursery industry could supply the 100,000 seedlings needed per square mile, let alone for any larger area.”

But there are still more questions beyond just the tactical.

“In a severely water-limited place, like the southwestern U.S.,” said Matthew Hurteau, a forest and fire ecology professor at the University of New Mexico, “if you’ve got the technology to fairly inexpensively and in a low carbon way purifying that water, is growing trees in the desert the best use of that water?”

Drawing down carbon emissions and providing co-benefits to local communities by planting trees could be a very valuable use of this water, but experts like Hanan and Hurteau would expect to see a detailed cost-benefit analysis that answers questions like:

  • How suitable is this land for trees?
  • Are these the right plants?
  • Are they native species or exotic species?
  • What are they going to do to the existing ecosystems?
  • What will be lost by adding trees into these systems?

And will the carbon stored actually be enough to make a dent in our carbon problem? Hanan is skeptical because trees grown in the desert certainly won’t be the huge trees of the tropical rainforest, and will probably have a fraction of the biomass. Trees in the desert probably won’t ever be the lungs of the earth, but can or should they be a tiny inhale in the process?

14 climate tech investors share their H1 2022 strategies

More TechCrunch

Expedia says Rathi Murthy and Sreenivas Rachamadugu, respectively its CTO and senior vice president of core services product & engineering, are no longer employed at the travel booking company. In…

Expedia says two execs dismissed after ‘violation of company policy’

When Jeffrey Wang posted to X asking if anyone wanted to go in on an order of fancy-but-affordable office nap pods, he didn’t expect the post to go viral.

With AI startups booming, nap pods and Silicon Valley hustle culture are back

A new crop of early-stage startups — along with some recent VC investments — illustrates a niche emerging in the autonomous vehicle technology sector. Unlike the companies bringing robotaxis to…

VCs and the military are fueling self-driving startups that don’t need roads

When the founders of Sagetap, Sahil Khanna and Kevin Hughes, started working at early-stage enterprise software startups, they were surprised to find that the companies they worked at were trying…

Deal Dive: Sagetap looks to bring enterprise software sales into the 21st century

Keeping up with an industry as fast-moving as AI is a tall order. So until an AI can do it for you, here’s a handy roundup of recent stories in the world…

This Week in AI: OpenAI moves away from safety

After Apple loosened its App Store guidelines to permit game emulators, the retro game emulator Delta — an app 10 years in the making — hit the top of the…

Adobe comes after indie game emulator Delta for copying its logo

Meta is once again taking on its competitors by developing a feature that borrows concepts from others — in this case, BeReal and Snapchat. The company is developing a feature…

Meta’s latest experiment borrows from BeReal’s and Snapchat’s core ideas

Welcome to Startups Weekly! We’ve been drowning in AI news this week, with Google’s I/O setting the pace. And Elon Musk rages against the machine.

Startups Weekly: It’s the dawning of the age of AI — plus,  Musk is raging against the machine

IndieBio’s Bay Area incubator is about to debut its 15th cohort of biotech startups. We took special note of a few, which were making some major, bordering on ludicrous, claims…

IndieBio’s SF incubator lineup is making some wild biotech promises

YouTube TV has announced that its multiview feature for watching four streams at once is now available on Android phones and tablets. The Android launch comes two months after YouTube…

YouTube TV’s ‘multiview’ feature is now available on Android phones and tablets

Featured Article

Two Santa Cruz students uncover security bug that could let millions do their laundry for free

CSC ServiceWorks provides laundry machines to thousands of residential homes and universities, but the company ignored requests to fix a security bug.

1 day ago
Two Santa Cruz students uncover security bug that could let millions do their laundry for free

OpenAI’s Superalignment team, responsible for developing ways to govern and steer “superintelligent” AI systems, was promised 20% of the company’s compute resources, according to a person from that team. But…

OpenAI created a team to control ‘superintelligent’ AI — then let it wither, source says

TechCrunch Disrupt 2024 is just around the corner, and the buzz is palpable. But what if we told you there’s a chance for you to not just attend, but also…

Harness the TechCrunch Effect: Host a Side Event at Disrupt 2024

Decks are all about telling a compelling story and Goodcarbon does a good job on that front. But there’s important information missing too.

Pitch Deck Teardown: Goodcarbon’s $5.5M seed deck

Slack is making it difficult for its customers if they want the company to stop using its data for model training.

Slack under attack over sneaky AI training policy

A Texas-based company that provides health insurance and benefit plans disclosed a data breach affecting almost 2.5 million people, some of whom had their Social Security number stolen. WebTPA said…

Healthcare company WebTPA discloses breach affecting 2.5 million people

Featured Article

Microsoft dodges UK antitrust scrutiny over its Mistral AI stake

Microsoft won’t be facing antitrust scrutiny in the U.K. over its recent investment into French AI startup Mistral AI.

1 day ago
Microsoft dodges UK antitrust scrutiny over its Mistral AI stake

Ember has partnered with HSBC in the U.K. so that the bank’s business customers can access Ember’s services from their online accounts.

Embedded finance is still trendy as accounting automation startup Ember partners with HSBC UK

Kudos uses AI to figure out consumer spending habits so it can then provide more personalized financial advice, like maximizing rewards and utilizing credit effectively.

Kudos lands $10M for an AI smart wallet that picks the best credit card for purchases

The EU’s warning comes after Microsoft failed to respond to a legally binding request for information that focused on its generative AI tools.

EU warns Microsoft it could be fined billions over missing GenAI risk info

The prospects for troubled banking-as-a-service startup Synapse have gone from bad to worse this week after a United States Trustee filed an emergency motion on Wednesday.  The trustee is asking…

A US Trustee wants troubled fintech Synapse to be liquidated via Chapter 7 bankruptcy, cites ‘gross mismanagement’

U.K.-based Seraphim Space is spinning up its 13th accelerator program, with nine participating companies working on a range of tech from propulsion to in-space manufacturing and space situational awareness. The…

Seraphim’s latest space accelerator welcomes nine companies

OpenAI has reached a deal with Reddit to use the social news site’s data for training AI models. In a blog post on OpenAI’s press relations site, the company said…

OpenAI inks deal to train AI on Reddit data

X users will now be able to discover posts from new Communities that are trending directly from an Explore tab within the section.

X pushes more users to Communities

For Mark Zuckerberg’s 40th birthday, his wife got him a photoshoot. Zuckerberg gives the camera a sly smile as he sits amid a carefully crafted re-creation of his childhood bedroom.…

Mark Zuckerberg’s makeover: Midlife crisis or carefully crafted rebrand?

Strava announced a slew of features, including AI to weed out leaderboard cheats, a new ‘family’ subscription plan, dark mode and more.

Strava taps AI to weed out leaderboard cheats, unveils ‘family’ plan, dark mode and more

We all fall down sometimes. Astronauts are no exception. You need to be in peak physical condition for space travel, but bulky space suits and lower gravity levels can be…

Astronauts fall over. Robotic limbs can help them back up.

Microsoft will launch its custom Cobalt 100 chips to customers as a public preview at its Build conference next week, TechCrunch has learned. In an analyst briefing ahead of Build,…

Microsoft’s custom Cobalt chips will come to Azure next week

What a wild week for transportation news! It was a smorgasbord of news that seemed to touch every sector and theme in transportation.

Tesla keeps cutting jobs and the feds probe Waymo

Sony Music Group has sent letters to more than 700 tech companies and music streaming services to warn them not to use its music to train AI without explicit permission.…

Sony Music warns tech companies over ‘unauthorized’ use of its content to train AI