Sustainable Urban Farming Has a Rising Hot Star: Bugs
In Sydney, Australia, in the basement of an inner-city high-rise, lives a mass of unexpected inhabitants: millions of maggots. The insects are far from unwelcome. They are there to feast on the food waste generated by the building's human residents.
Goterra, the start-up that installed the maggots in the building in December, belongs to the rapidly expanding insect agriculture industry, which is experiencing a surge of investment worldwide.
The maggots – the larvae of the black soldier fly – are voracious, unfussy eaters. As adult flies, they don't eat, so the young fatten up swiftly on whatever they can get. Goterra's basement colony can munch through 5 metric tons of waste in a day.
"Maggots are nature's cleaners," says Bob Gordon, Head of Growth at Goterra. "They're a great tool to manage waste streams."
Their capacity to consume presents a neat response to the problem of food waste, which contributes up to 8% of global greenhouse gas emissions each year as it rots in landfill.
"The maggots eat the food fairly fresh," Gordon says. "So, there's minimal degradation and you don't get those methane emissions."
Alongside their ability to devour waste, the soldier fly larvae hold further agricultural promise: they yield an incredibly efficient protein. After the maggots have binged for about 12 days, Goterra harvests and processes them into a protein-rich livestock feed. Their excrement, known as frass, is also collected and turned into soil conditioner.
"We are producing protein in a basement," says Gordon. "It's urban farming – really sustainable, urban farming."
Goterra's module in the basement at Barangaroo, Sydney.
Supplied by Goterra
Goterra's founder Olympia Yarger started producing the insects in "buckets in her backyard" in 2016. Today, Goterra has a large-scale processing plant and has developed proprietary modules – in shipping containers – that use robotics to manage the larvae.
The modules have been installed on site at municipal buildings, hospitals, supermarkets, several McDonald's restaurants, and a range of smaller enterprises in Australia. Users pay a subscription fee and simply pour in the waste; Goterra visits once a fortnight to harvest the bugs.
Insect agriculture is well established outside of the West, and the practice is gaining traction around the world. China has mega-facilities that can process hundreds of tons of waste in a day. In Kenya, a program recently trained 2000 farmers in soldier fly farming to boost their economic security. French biotech company InnovaFeed, in partnership with US agricultural heavyweight ADM, plans to build "the world's largest insect protein facility" in Illinois this year.
"The [maggots] are science fiction on earth. Watching them work is awe-inspiring."
But the concept is still not to everyone's taste.
"This is still a topic that I say is a bit like black liquorice – people tend to either really like it or really don't," says Wendy Lu McGill, Communications Director at the North American Coalition of Insect Agriculture (NACIA).
Formed in 2016, NACIA now has over 100 members – including researchers and commercial producers of black soldier flies, meal worms and crickets.
McGill says there have been a few iterations of insect agriculture in the US – beginning with worms produced for bait after World War II then shifting to food for exotic pets. The current focus – "insects as food and feed" – took root about a decade ago, with the establishment of the first commercial farms for this purpose.
"We're starting to see more expansion in the U.S. and a lot of the larger investments have been for black soldier fly producers," McGill says. "They tend to have larger facilities and the animal feed market they're looking at is potentially quite large."
InnovaFeed's Illinois facility is set to produce 60,000 metric tons of animal feed protein per year.
"They'll be trying to employ many different circular principles," McGill says of the project. "For example, the heat from the feed factory – the excess heat that would normally just be vented – will be used to heat the other side that's raising the black soldier fly."
Although commercial applications have started to flourish recently, scientific knowledge of the black soldier fly's potential has existed for decades.
Dr. Jeffery Tomberlin, an entomologist at Texas A&M University, has been studying the insect for over 20 years, contributing to key technologies used in the industry. He also founded Evo, a black soldier fly company in Texas, which feeds its larvae the waste from a local bakery and distillery.
"They are science fiction on earth," he says of the maggots. "Watching them work is awe-inspiring."
Tomberlin says fly farms can work effectively at different scales, and present possibilities for non-Western countries to shift towards "commodity independence."
"You don't have to have millions of dollars invested to be successful in producing this insect," he says. "[A farm] can be as simple as an open barn along the equator to a 30,000 square-foot indoor facility in the Netherlands."
As the world's population balloons, food insecurity is an increasing concern. By 2050, the UN predicts that to feed our projected population we will need to ramp up food production by at least 60%. Insect agriculture, which uses very little land and water compared to traditional livestock farming, could play a key role.
Insects may become more common human food, but the current commercial focus is animal feed. Aquaculture is a key market, with insects presenting an alternative to fish meal derived from over-exploited stocks. Insect meal is also increasingly popular in pet food, particularly in Europe.
While recent investment has been strong – NACIA says 2020 was the best year yet – reaching a scale that can match existing agricultural industries and providing a competitive price point are still hurdles for insect agriculture.
But COVID-19 has strengthened the argument for new agricultural approaches, such as the decentralized, indoor systems and circular principles employed by insect farms.
"This has given the world a preview – which no one wanted – of [future] supply chain disruptions," says McGill.
As the industry works to meet demand, Tomberlin predicts diversification and product innovation: "I think food science is going to play a big part in that. They can take an insect and create ice cream." (Dried soldier fly larvae "taste kind of like popcorn," if you were wondering.)
Tomberlin says the insects could even become an interplanetary protein source: "I do believe in that. I mean, if we're going to colonize other planets, we need to be sustainable."
But he issues a word of caution about the industry growing too big, too fast: "I think we as an industry need to be very careful of how we harness and apply [our knowledge]. The black soldier fly is considered the crown jewel today, but if it's mismanaged, it can be relegated back to a past."
Goterra's Gordon also warns against rushing into mass production: "If you're just replacing big intensive animal agriculture with big intensive animal agriculture with more efficient animals, then what's the change you're really effecting?"
But he expects the industry will continue its rise though the next decade, and Goterra – fuelled by recent $8 million Series A funding – plans to expand internationally this year.
"Within 10 years' time, I would like to see the vast majority of our unavoidable food waste being used to produce maggots to go into a protein application," Gordon says.
"There's no lack of demand. And there's no lack of food waste."
New elevators could lift up our access to space
Story by Big Think
When people first started exploring space in the 1960s, it cost upwards of $80,000 (adjusted for inflation) to put a single pound of payload into low-Earth orbit.
A major reason for this high cost was the need to build a new, expensive rocket for every launch. That really started to change when SpaceX began making cheap, reusable rockets, and today, the company is ferrying customer payloads to LEO at a price of just $1,300 per pound.
This is making space accessible to scientists, startups, and tourists who never could have afforded it previously, but the cheapest way to reach orbit might not be a rocket at all — it could be an elevator.
The space elevator
The seeds for a space elevator were first planted by Russian scientist Konstantin Tsiolkovsky in 1895, who, after visiting the 1,000-foot (305 m) Eiffel Tower, published a paper theorizing about the construction of a structure 22,000 miles (35,400 km) high.
This would provide access to geostationary orbit, an altitude where objects appear to remain fixed above Earth’s surface, but Tsiolkovsky conceded that no material could support the weight of such a tower.
We could then send electrically powered “climber” vehicles up and down the tether to deliver payloads to any Earth orbit.
In 1959, soon after Sputnik, Russian engineer Yuri N. Artsutanov proposed a way around this issue: instead of building a space elevator from the ground up, start at the top. More specifically, he suggested placing a satellite in geostationary orbit and dropping a tether from it down to Earth’s equator. As the tether descended, the satellite would ascend. Once attached to Earth’s surface, the tether would be kept taut, thanks to a combination of gravitational and centrifugal forces.
We could then send electrically powered “climber” vehicles up and down the tether to deliver payloads to any Earth orbit. According to physicist Bradley Edwards, who researched the concept for NASA about 20 years ago, it’d cost $10 billion and take 15 years to build a space elevator, but once operational, the cost of sending a payload to any Earth orbit could be as low as $100 per pound.
“Once you reduce the cost to almost a Fed-Ex kind of level, it opens the doors to lots of people, lots of countries, and lots of companies to get involved in space,” Edwards told Space.com in 2005.
In addition to the economic advantages, a space elevator would also be cleaner than using rockets — there’d be no burning of fuel, no harmful greenhouse emissions — and the new transport system wouldn’t contribute to the problem of space junk to the same degree that expendable rockets do.
So, why don’t we have one yet?
Tether troubles
Edwards wrote in his report for NASA that all of the technology needed to build a space elevator already existed except the material needed to build the tether, which needs to be light but also strong enough to withstand all the huge forces acting upon it.
The good news, according to the report, was that the perfect material — ultra-strong, ultra-tiny “nanotubes” of carbon — would be available in just two years.
“[S]teel is not strong enough, neither is Kevlar, carbon fiber, spider silk, or any other material other than carbon nanotubes,” wrote Edwards. “Fortunately for us, carbon nanotube research is extremely hot right now, and it is progressing quickly to commercial production.”Unfortunately, he misjudged how hard it would be to synthesize carbon nanotubes — to date, no one has been able to grow one longer than 21 inches (53 cm).
Further research into the material revealed that it tends to fray under extreme stress, too, meaning even if we could manufacture carbon nanotubes at the lengths needed, they’d be at risk of snapping, not only destroying the space elevator, but threatening lives on Earth.
Looking ahead
Carbon nanotubes might have been the early frontrunner as the tether material for space elevators, but there are other options, including graphene, an essentially two-dimensional form of carbon that is already easier to scale up than nanotubes (though still not easy).
Contrary to Edwards’ report, Johns Hopkins University researchers Sean Sun and Dan Popescu say Kevlar fibers could work — we would just need to constantly repair the tether, the same way the human body constantly repairs its tendons.
“Using sensors and artificially intelligent software, it would be possible to model the whole tether mathematically so as to predict when, where, and how the fibers would break,” the researchers wrote in Aeon in 2018.
“When they did, speedy robotic climbers patrolling up and down the tether would replace them, adjusting the rate of maintenance and repair as needed — mimicking the sensitivity of biological processes,” they continued.Astronomers from the University of Cambridge and Columbia University also think Kevlar could work for a space elevator — if we built it from the moon, rather than Earth.
They call their concept the Spaceline, and the idea is that a tether attached to the moon’s surface could extend toward Earth’s geostationary orbit, held taut by the pull of our planet’s gravity. We could then use rockets to deliver payloads — and potentially people — to solar-powered climber robots positioned at the end of this 200,000+ mile long tether. The bots could then travel up the line to the moon’s surface.
This wouldn’t eliminate the need for rockets to get into Earth’s orbit, but it would be a cheaper way to get to the moon. The forces acting on a lunar space elevator wouldn’t be as strong as one extending from Earth’s surface, either, according to the researchers, opening up more options for tether materials.
“[T]he necessary strength of the material is much lower than an Earth-based elevator — and thus it could be built from fibers that are already mass-produced … and relatively affordable,” they wrote in a paper shared on the preprint server arXiv.
After riding up the Earth-based space elevator, a capsule would fly to a space station attached to the tether of the moon-based one.
Electrically powered climber capsules could go up down the tether to deliver payloads to any Earth orbit.
Adobe Stock
Some Chinese researchers, meanwhile, aren’t giving up on the idea of using carbon nanotubes for a space elevator — in 2018, a team from Tsinghua University revealed that they’d developed nanotubes that they say are strong enough for a tether.
The researchers are still working on the issue of scaling up production, but in 2021, state-owned news outlet Xinhua released a video depicting an in-development concept, called “Sky Ladder,” that would consist of space elevators above Earth and the moon.
After riding up the Earth-based space elevator, a capsule would fly to a space station attached to the tether of the moon-based one. If the project could be pulled off — a huge if — China predicts Sky Ladder could cut the cost of sending people and goods to the moon by 96 percent.
The bottom line
In the 120 years since Tsiolkovsky looked at the Eiffel Tower and thought way bigger, tremendous progress has been made developing materials with the properties needed for a space elevator. At this point, it seems likely we could one day have a material that can be manufactured at the scale needed for a tether — but by the time that happens, the need for a space elevator may have evaporated.
Several aerospace companies are making progress with their own reusable rockets, and as those join the market with SpaceX, competition could cause launch prices to fall further.
California startup SpinLaunch, meanwhile, is developing a massive centrifuge to fling payloads into space, where much smaller rockets can propel them into orbit. If the company succeeds (another one of those big ifs), it says the system would slash the amount of fuel needed to reach orbit by 70 percent.
Even if SpinLaunch doesn’t get off the ground, several groups are developing environmentally friendly rocket fuels that produce far fewer (or no) harmful emissions. More work is needed to efficiently scale up their production, but overcoming that hurdle will likely be far easier than building a 22,000-mile (35,400-km) elevator to space.
New tech aims to make the ocean healthier for marine life
A defunct drydock basin arched by a rusting 19th century steel bridge seems an incongruous place to conduct state-of-the-art climate science. But this placid and protected sliver of water connecting Brooklyn’s Navy Yard to the East River was just right for Garrett Boudinot to float a small dock topped with water carbon-sensing gear. And while his system right now looks like a trio of plastic boxes wired up together, it aims to mediate the growing ocean acidification problem, caused by overabundance of dissolved carbon dioxide.
Boudinot, a biogeochemist and founder of a carbon-management startup called Vycarb, is honing his method for measuring CO2 levels in water, as well as (at least temporarily) correcting their negative effects. It’s a challenge that’s been occupying numerous climate scientists as the ocean heats up, and as states like New York recognize that reducing emissions won’t be enough to reach their climate goals; they’ll have to figure out how to remove carbon, too.
To date, though, methods for measuring CO2 in water at scale have been either intensely expensive, requiring fancy sensors that pump CO2 through membranes; or prohibitively complicated, involving a series of lab-based analyses. And that’s led to a bottleneck in efforts to remove carbon as well.
But recently, Boudinot cracked part of the code for measurement and mitigation, at least on a small scale. While the rest of the industry sorts out larger intricacies like getting ocean carbon markets up and running and driving carbon removal at billion-ton scale in centralized infrastructure, his decentralized method could have important, more immediate implications.
Specifically, for shellfish hatcheries, which grow seafood for human consumption and for coastal restoration projects. Some of these incubators for oysters and clams and scallops are already feeling the negative effects of excess carbon in water, and Vycarb’s tech could improve outcomes for the larval- and juvenile-stage mollusks they’re raising. “We’re learning from these folks about what their needs are, so that we’re developing our system as a solution that’s relevant,” Boudinot says.
Ocean acidification can wreak havoc on developing shellfish, inhibiting their shells from growing and leading to mass die-offs.
Ocean waters naturally absorb CO2 gas from the atmosphere. When CO2 accumulates faster than nature can dissipate it, it reacts with H2O molecules, forming carbonic acid, H2CO3, which makes the water column more acidic. On the West Coast, acidification occurs when deep, carbon dioxide-rich waters upwell onto the coast. This can wreak havoc on developing shellfish, inhibiting their shells from growing and leading to mass die-offs; this happened, disastrously, at Pacific Northwest oyster hatcheries in 2007.
This type of acidification will eventually come for the East Coast, too, says Ryan Wallace, assistant professor and graduate director of environmental studies and sciences at Long Island’s Adelphi University, who studies acidification. But at the moment, East Coast acidification has other sources: agricultural runoff, usually in the form of nitrogen, and human and animal waste entering coastal areas. These excess nutrient loads cause algae to grow, which isn’t a problem in and of itself, Wallace says; but when algae die, they’re consumed by bacteria, whose respiration in turn bumps up CO2 levels in water.
“Unfortunately, this is occurring at the bottom [of the water column], where shellfish organisms live and grow,” Wallace says. Acidification on the East Coast is minutely localized, occurring closest to where nutrients are being released, as well as seasonally; at least one local shellfish farm, on Fishers Island in the Long Island Sound, has contended with its effects.
The second Vycarb pilot, ready to be installed at the East Hampton shellfish hatchery.
Courtesy of Vycarb
Besides CO2, ocean water contains two other forms of dissolved carbon — carbonate (CO3-) and bicarbonate (HCO3) — at all times, at differing levels. At low pH (acidic), CO2 prevails; at medium pH, HCO3 is the dominant form; at higher pH, CO3 dominates. Boudinot’s invention is the first real-time measurement for all three, he says. From the dock at the Navy Yard, his pilot system uses carefully calibrated but low-cost sensors to gauge the water’s pH and its corresponding levels of CO2. When it detects elevated levels of the greenhouse gas, the system mitigates it on the spot. It does this by adding a bicarbonate powder that’s a byproduct of agricultural limestone mining in nearby Pennsylvania. Because the bicarbonate powder is alkaline, it increases the water pH and reduces the acidity. “We drive a chemical reaction to increase the pH to convert greenhouse gas- and acid-causing CO2 into bicarbonate, which is HCO3,” Boudinot says. “And HCO3 is what shellfish and fish and lots of marine life prefers over CO2.”
This de-acidifying “buffering” is something shellfish operations already do to water, usually by adding soda ash (NaHCO3), which is also alkaline. Some hatcheries add soda ash constantly, just in case; some wait till acidification causes significant problems. Generally, for an overly busy shellfish farmer to detect acidification takes time and effort. “We’re out there daily, taking a look at the pH and figuring out how much we need to dose it,” explains John “Barley” Dunne, director of the East Hampton Shellfish Hatchery on Long Island. “If this is an automatic system…that would be much less labor intensive — one less thing to monitor when we have so many other things we need to monitor.”
Across the Sound at the hatchery he runs, Dunne annually produces 30 million hard clams, 6 million oysters, and “if we’re lucky, some years we get a million bay scallops,” he says. These mollusks are destined for restoration projects around the town of East Hampton, where they’ll create habitat, filter water, and protect the coastline from sea level rise and storm surge. So far, Dunne’s hatchery has largely escaped the ill effects of acidification, although his bay scallops are having a finicky year and he’s checking to see if acidification might be part of the problem. But “I think it's important to have these solutions ready-at-hand for when the time comes,” he says. That’s why he’s hosting a second, 70-liter Vycarb pilot starting this summer on a dock adjacent to his East Hampton operation; it will amp up to a 50,000 liter-system in a few months.
If it can buffer water over a large area, absolutely this will benefit natural spawns. -- John “Barley” Dunne.
Boudinot hopes this new pilot will act as a proof of concept for hatcheries up and down the East Coast. The area from Maine to Nova Scotia is experiencing the worst of Atlantic acidification, due in part to increased Arctic meltwater combining with Gulf of St. Lawrence freshwater; that decreases saturation of calcium carbonate, making the water more acidic. Boudinot says his system should work to adjust low pH regardless of the cause or locale. The East Hampton system will eventually test and buffer-as-necessary the water that Dunne pumps from the Sound into 100-gallon land-based tanks where larvae grow for two weeks before being transferred to an in-Sound nursery to plump up.
Dunne says this could have positive effects — not only on his hatchery but on wild shellfish populations, too, reducing at least one stressor their larvae experience (others include increasing water temperatures and decreased oxygen levels). “If it can buffer water over a large area, absolutely this will [benefit] natural spawns,” he says.
No one believes the Vycarb model — even if it proves capable of functioning at much greater scale — is the sole solution to acidification in the ocean. Wallace says new water treatment plants in New York City, which reduce nitrogen released into coastal waters, are an important part of the equation. And “certainly, some green infrastructure would help,” says Boudinot, like restoring coastal and tidal wetlands to help filter nutrient runoff.
In the meantime, Boudinot continues to collect data in advance of amping up his own operations. Still unknown is the effect of releasing huge amounts of alkalinity into the ocean. Boudinot says a pH of 9 or higher can be too harsh for marine life, plus it can also trigger a release of CO2 from the water back into the atmosphere. For a third pilot, on Governor’s Island in New York Harbor, Vycarb will install yet another system from which Boudinot’s team will frequently sample to analyze some of those and other impacts. “Let's really make sure that we know what the results are,” he says. “Let's have data to show, because in this carbon world, things behave very differently out in the real world versus on paper.”