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How Rapa Nui Lost a Tree, Only to Have It Sprout Up Elsewhere

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Tuesday, March 26, 2024

The tree that goes by toromiro has been a fragile expat for more than a half-century. Little Sophora toromiro, is far from home, no longer present on Rapa Nui, the Pacific island where it evolved. Also known as Easter Island, or Isla de Pascua in Spanish, Rapa Nui is a speck of land in the Pacific, 2,200 miles from the west coast of Chile. The tiny island encompasses just 63 square miles, and it is quite flat, with a maximum elevation of less than 1,700 feet. The last date of the toromiro’s tenure on Rapa Nui is uncertain. Some accounts say it went extinct in the wild in 1960. Others say that it was gone by 1962, when Karl Schanz, a German meteorologist, clambered down to see the tree in the crater where it had last been spotted, and it was gone. Was it removed? Did it die, tip over and return to the earth? We will never know. Although the toromiro is gone from Rapa Nui, it survives elsewhere through luck—and pluck. Over the past century, the intermittent collecting of the toromiro’s seeds and their replanting in mainland locations have given the species purchase elsewhere. Each tree is a member of a small diaspora, with only a handful surviving in about a dozen different public and private botanical gardens around the world. This is a story of survival, persistence and, perhaps in some ways, dumb luck—a tree in decline that was rescued and whose seeds were sent to other places. Mention Easter Island to almost anyone, and if they’ve heard of it, they’ve likely heard of its statues. Imprinted in the popular imagination are its enigmatic, massive stone sculptures, or moai. Curious investigators have speculated for more than two centuries about how more than 900 of these mysterious statues—the largest being more than 30 feet tall and weighing over 80 tons—might have been moved to locations around the island, traveling miles from the site where they were quarried. The toromiro, though, is an invisible tree on the island, its story known to very few, and its existence marked more by its absence than its presence. The tree does have many close relatives. The Sophora genus is speciose, as biologists say—a crowded taxon consisting of some 60 different species, including a dozen closely related oceanic ones scattered across the Pacific. The toromiro is more of a shrub than a tree, and none of its close relatives is large—at least from descriptions recorded over the past century. The northernmost outpost for the Sophora genus is in Hawaiʻi, where Sophora chrysophylla is the primary food source for the palila, a critically endangered honeycreeper. Without S. chrysophylla, known as mamane in Hawaiian, the palila would not have survived the last century as its range dwindled. The subterranean pollen record reveals that the toromiro was abundant across much of Rapa Nui, where many other now-extinct plants also thrived. Paleobotanical evidence shows that the tree’s presence on the island dates back at least 35,000 years. Its seeds are both buoyant and salt-resistant, and they probably first arrived by water, floating onto the island, probably from another Pacific island, and then it did what species do: continued its evolutionary journey in a new place to become the tree we know today. But even before the toromiro disappeared from the island, it had been without a lot of endemic companions. Fewer than 30 indigenous seed-bearing plant species have survived on Rapa Nui to the present day, and weeds, along with naturalized, cultivated shrubs, are now the main plants growing there. The toromiro did not disappear precipitously but experienced a protracted decline. Humans arrived in Rapa Nui around the 12th century, probably not long after Polynesians reached the Hawaiian archipelago. Some hundreds of years after humans’ arrival, the island experienced a painful drop in biodiversity, and its carrying capacity plummeted as the native palm forests disappeared, replaced by grasslands. Food grew scarce, and occupants fled, thinning down to around 100 Rapa Nui at one point in the 19th century. In his deterministic 2005 book Collapse: How Societies Choose to Fail or Succeed, Jared Diamond claimed the occupants were lousy land managers. His analysis of why Rapa Nui became denuded of its plant life is now out of date, as later studies have revealed the island’s complexities. To sketch the story of the weakening grip of native plant life on Rapa Nui as a predictable story of human arrogance intersecting with a small, remote and evolutionarily vulnerable spit of land is tempting, but the tale is more nuanced than that. Natives there recorded centuries-old histories of careful but intermittent conservation strategies. Some scholars have asserted that the Little Ice Age stressed resources on the island between the 16th and 19th centuries, leading to the disappearance of palms and other important contributors to the islanders’ activities and well-being. Others have pointed to prolonged droughts, while still others have continued to argue that humans were highly complicit in the island’s declining biodiversity. Were groves of palm trees decimated to create systems for rolling the giant stone carvings from quarry to coastline, where most of them have sat for many hundreds of years? Perhaps. However the palms disappeared, their loss seems to have been a factor in the tumbling downturn of the island’s other trees, including the toromiro. The palms had made up the great majority of Rapa Nui’s tree cover, some 16 million trees that blanketed about 70 percent of the island. Some controversy remains about what particular species of palm flourished, but many believe it was Paschalococos disperta, the Rapa Nui palm. Jaime Espejo, a Chilean botanist who’s written extensively about the toromiro, noted that it probably lived in the undergrowth of the palm, lodged in an ancient ecosystem that no longer exists. Paleobotanists and archaeologists studying the island spotted the widespread loss of the palms in their investigations. At the same time, they found that the number of fish bones found in waste middens around the island dropped as fishing boats could no longer be constructed in large numbers from trees. The loss of access to fish must have been a devastating turn, because the human residents’ main proteins came from the sea. Soil erosion, likely exacerbated by deforestation and agriculture, led to further losses of the tree. Hooved animals, arriving with European explorers in the 18th century, were also certain culprits in the toromiro’s decline and disappearance. In Hawaiʻi, sheep consume that archipelago’s species of Sophora. Another creature implicated in the destruction of much of both Rapa Nui’s and Hawaiʻi’s plant life was the Polynesian rat (Rattus exulans), as well as the bigger ship rat (Rattus rattus) and Norwegian rat (Rattus norvegicus). These rats, landing on new island homes and able to reproduce quickly, found abundant food in the form of native seeds, plants and invertebrates—and no predators. They laid waste to plant life with shocking speed. An aerial view of a toromiro in Barcelona, Spain Daderot via Wikimedia CC0 Early European accounts and pollen records tell us that by about 1600, forests in the island’s craters had disappeared, and, with that, the toromiro declined into long-term scarcity and then extirpation. The New Zealand anthropologist Steven Fischer has noted that the last forest was probably cut for firewood around 1640, making wood the most valuable commodity on the island. Driftwood became precious. So scarce was wood, Fischer observes, that the pan-Polynesian word rakau, meaning “tree,” “timber” or “wood,” came to mean “riches” or “wealth” in the old Rapa Nui language—a meaning not present in any other use of the word elsewhere in Polynesia, including in Tahiti, Tonga, Hawaiʻi and New Zealand. It’s ironic that after the deforestation of the island’s trees, new linguistic meanings sprouted out of the island’s impending botanical doom. Amid these centuries-long difficulties, but long before the toromiro disappeared, a wood-based culture thrived. The Rapa Nui had a particular passion for carving; beyond their giant stone statues, they favored the toromiro for its durable and fine-grained wood and reddish hue. Although primarily used for ritual objects, the toromiro was also serviceable for building material in houses, household utensils, statuettes and paddles. These artifacts survive in museums around the world. Some of them are hundreds of years old, and they might provide unexpected addenda to our understandings of the tree’s deeper history, offered up through dendrochronological analysis. Studying the annual growth rings in the wood could provide details we lack: the pace of growth of the wood, environmental pressures acting on the tree, its ultimate size and many of the other clues revealed through laboratory work with wood specimens. Part of our lack of knowledge about the tree’s wood is because it has always been uncommon on the island, at least since Western contact. Rapa Nui came with inherent geographic disadvantages for plant survival, including few sheltered habitats with steep hillsides or deep ravines in which toromiro could remain hidden away from humans. The three volcanic craters on the island are the only such hiding places. In 1911, the Chilean botanist Francisco Fuentes noted that the toromiro was rare, only to be found in Rano Kau, the largest of the craters. The Swedish botanist Carl Skottsberg, who also worked on Hawaiian flora, visited Rano Kau in 1917 and found only a single specimen. A compelling global exploration of nature and survival as seen through a dozen species of trees. The final contact with the tree on its native soil occurred when the Norwegian explorer Thor Heyerdahl collected seeds from the last surviving example. This was likely the same tree that Skottsberg had found in the shelter of Rano Kau. The egg-shaped crater is about a mile across and has its own microclimate, largely out of the winds and weather, and protected from grazing ungulates by a rock formation. Foot traffic remained down in the last century, as little else lives in the crater that can be harvested or cut down. Innumerable swampy pockets of water make the area difficult to traverse. A beautiful, multicolored, shallow lake of open water and floating mats of peat cover much of the bottom of the crater. There, the tiny toromiro held on. Heyerdahl, who had already been traveling around the Pacific Ocean in the 1940s, became famous, or infamous, for floating a radical new theory: that the islands in the Pacific had been populated initially by American Indians from the mainland of South America, rather than by people from Asia or from other Polynesian islands. In 1947, he launched an expedition with a primitive raft named Kon-Tiki and made a 5,000-mile journey, heading west from Peru. What’s often lost in the voluminous writings about Heyerdahl and his oceanfaring obsessions was his interest in Rapa Nui. Björn Aldén, a Swedish botanist with the Gothenburg Botanical Garden, became friends with Heyerdahl and has worked to return the toromiro to its native land. In a letter to Björn, Heyerdahl decried the “tankelöse treskjaerere,” or “thoughtless woodcutters.” He noted how good it felt to have helped to save the species by collecting a handful of seeds that hung from the tree’s sole remaining branch. Heyerdahl couldn’t recount the exact date, or even the year, but thought it was sometime in late 1955 or early 1956. Heyerdahl handed the seeds off to paleobotanist Olaf Selling in Stockholm. They went to Gothenburg from there. Locals have a strain of national pride in Gothenburg for their role in the tree’s cultivation and survival. But recently, researchers in Chile discovered that another botanist preceded Heyerdahl in getting seeds off the island. Efraín Volosky Yadlin, an Argentinian-born immigrant, participated in the first agronomic studies on Rapa Nui. Sent there by the Chilean Ministry of Agriculture in the early 1950s, Volosky Yadlin collected seeds, apparently from the same tree that Heyerdahl would come upon a few years later, and proceeded to carry out his own propagation tests on the toromiro. Now the tree remains far afield, surviving in about a dozen locations around the world, mostly in botanical gardens including in Chile, in London and in southern France. Ultimately, researchers want to return the toromiro to Rapa Nui. But the tree still confronts challenges to surviving on its native ground, including a lack of genetic diversity and degraded soil on Rapa Nui. Past efforts to reestablish the tree have failed, but botanists are doing their best to overcome these hurdles. More studies will help researchers understand just what it will take to help the tree take root back on Rapa Nui and successfully end a long and difficult voyage. Excerpted from Twelve Trees: The Deep Roots of Our Future by Daniel Lewis. Published by Avid Reader Press / Simon & Schuster. Copyright © 2024. All rights reserved. Get the latest Science stories in your inbox. A Note to our Readers Smithsonian magazine participates in affiliate link advertising programs. If you purchase an item through these links, we receive a commission.

Before the toromiro disappeared from the island, at least two men grabbed seeds from the last remaining plant and brought them home

The tree that goes by toromiro has been a fragile expat for more than a half-century. Little Sophora toromiro, is far from home, no longer present on Rapa Nui, the Pacific island where it evolved. Also known as Easter Island, or Isla de Pascua in Spanish, Rapa Nui is a speck of land in the Pacific, 2,200 miles from the west coast of Chile. The tiny island encompasses just 63 square miles, and it is quite flat, with a maximum elevation of less than 1,700 feet.

The last date of the toromiro’s tenure on Rapa Nui is uncertain. Some accounts say it went extinct in the wild in 1960. Others say that it was gone by 1962, when Karl Schanz, a German meteorologist, clambered down to see the tree in the crater where it had last been spotted, and it was gone. Was it removed? Did it die, tip over and return to the earth? We will never know. Although the toromiro is gone from Rapa Nui, it survives elsewhere through luck—and pluck. Over the past century, the intermittent collecting of the toromiro’s seeds and their replanting in mainland locations have given the species purchase elsewhere. Each tree is a member of a small diaspora, with only a handful surviving in about a dozen different public and private botanical gardens around the world. This is a story of survival, persistence and, perhaps in some ways, dumb luck—a tree in decline that was rescued and whose seeds were sent to other places.


Mention Easter Island to almost anyone, and if they’ve heard of it, they’ve likely heard of its statues. Imprinted in the popular imagination are its enigmatic, massive stone sculptures, or moai. Curious investigators have speculated for more than two centuries about how more than 900 of these mysterious statues—the largest being more than 30 feet tall and weighing over 80 tons—might have been moved to locations around the island, traveling miles from the site where they were quarried. The toromiro, though, is an invisible tree on the island, its story known to very few, and its existence marked more by its absence than its presence.

The tree does have many close relatives. The Sophora genus is speciose, as biologists say—a crowded taxon consisting of some 60 different species, including a dozen closely related oceanic ones scattered across the Pacific. The toromiro is more of a shrub than a tree, and none of its close relatives is large—at least from descriptions recorded over the past century. The northernmost outpost for the Sophora genus is in Hawaiʻi, where Sophora chrysophylla is the primary food source for the palila, a critically endangered honeycreeper. Without S. chrysophylla, known as mamane in Hawaiian, the palila would not have survived the last century as its range dwindled.

The subterranean pollen record reveals that the toromiro was abundant across much of Rapa Nui, where many other now-extinct plants also thrived. Paleobotanical evidence shows that the tree’s presence on the island dates back at least 35,000 years. Its seeds are both buoyant and salt-resistant, and they probably first arrived by water, floating onto the island, probably from another Pacific island, and then it did what species do: continued its evolutionary journey in a new place to become the tree we know today. But even before the toromiro disappeared from the island, it had been without a lot of endemic companions. Fewer than 30 indigenous seed-bearing plant species have survived on Rapa Nui to the present day, and weeds, along with naturalized, cultivated shrubs, are now the main plants growing there.

The toromiro did not disappear precipitously but experienced a protracted decline. Humans arrived in Rapa Nui around the 12th century, probably not long after Polynesians reached the Hawaiian archipelago. Some hundreds of years after humans’ arrival, the island experienced a painful drop in biodiversity, and its carrying capacity plummeted as the native palm forests disappeared, replaced by grasslands. Food grew scarce, and occupants fled, thinning down to around 100 Rapa Nui at one point in the 19th century. In his deterministic 2005 book Collapse: How Societies Choose to Fail or Succeed, Jared Diamond claimed the occupants were lousy land managers. His analysis of why Rapa Nui became denuded of its plant life is now out of date, as later studies have revealed the island’s complexities. To sketch the story of the weakening grip of native plant life on Rapa Nui as a predictable story of human arrogance intersecting with a small, remote and evolutionarily vulnerable spit of land is tempting, but the tale is more nuanced than that. Natives there recorded centuries-old histories of careful but intermittent conservation strategies. Some scholars have asserted that the Little Ice Age stressed resources on the island between the 16th and 19th centuries, leading to the disappearance of palms and other important contributors to the islanders’ activities and well-being. Others have pointed to prolonged droughts, while still others have continued to argue that humans were highly complicit in the island’s declining biodiversity. Were groves of palm trees decimated to create systems for rolling the giant stone carvings from quarry to coastline, where most of them have sat for many hundreds of years? Perhaps.

However the palms disappeared, their loss seems to have been a factor in the tumbling downturn of the island’s other trees, including the toromiro. The palms had made up the great majority of Rapa Nui’s tree cover, some 16 million trees that blanketed about 70 percent of the island. Some controversy remains about what particular species of palm flourished, but many believe it was Paschalococos disperta, the Rapa Nui palm. Jaime Espejo, a Chilean botanist who’s written extensively about the toromiro, noted that it probably lived in the undergrowth of the palm, lodged in an ancient ecosystem that no longer exists. Paleobotanists and archaeologists studying the island spotted the widespread loss of the palms in their investigations. At the same time, they found that the number of fish bones found in waste middens around the island dropped as fishing boats could no longer be constructed in large numbers from trees. The loss of access to fish must have been a devastating turn, because the human residents’ main proteins came from the sea.

Soil erosion, likely exacerbated by deforestation and agriculture, led to further losses of the tree. Hooved animals, arriving with European explorers in the 18th century, were also certain culprits in the toromiro’s decline and disappearance. In Hawaiʻi, sheep consume that archipelago’s species of Sophora. Another creature implicated in the destruction of much of both Rapa Nui’s and Hawaiʻi’s plant life was the Polynesian rat (Rattus exulans), as well as the bigger ship rat (Rattus rattus) and Norwegian rat (Rattus norvegicus). These rats, landing on new island homes and able to reproduce quickly, found abundant food in the form of native seeds, plants and invertebrates—and no predators. They laid waste to plant life with shocking speed.

Aerial of Sophora Toromiro
An aerial view of a toromiro in Barcelona, Spain Daderot via Wikimedia CC0

Early European accounts and pollen records tell us that by about 1600, forests in the island’s craters had disappeared, and, with that, the toromiro declined into long-term scarcity and then extirpation. The New Zealand anthropologist Steven Fischer has noted that the last forest was probably cut for firewood around 1640, making wood the most valuable commodity on the island. Driftwood became precious. So scarce was wood, Fischer observes, that the pan-Polynesian word rakau, meaning “tree,” “timber” or “wood,” came to mean “riches” or “wealth” in the old Rapa Nui language—a meaning not present in any other use of the word elsewhere in Polynesia, including in Tahiti, Tonga, Hawaiʻi and New Zealand. It’s ironic that after the deforestation of the island’s trees, new linguistic meanings sprouted out of the island’s impending botanical doom.

Amid these centuries-long difficulties, but long before the toromiro disappeared, a wood-based culture thrived. The Rapa Nui had a particular passion for carving; beyond their giant stone statues, they favored the toromiro for its durable and fine-grained wood and reddish hue. Although primarily used for ritual objects, the toromiro was also serviceable for building material in houses, household utensils, statuettes and paddles. These artifacts survive in museums around the world. Some of them are hundreds of years old, and they might provide unexpected addenda to our understandings of the tree’s deeper history, offered up through dendrochronological analysis. Studying the annual growth rings in the wood could provide details we lack: the pace of growth of the wood, environmental pressures acting on the tree, its ultimate size and many of the other clues revealed through laboratory work with wood specimens.

Part of our lack of knowledge about the tree’s wood is because it has always been uncommon on the island, at least since Western contact. Rapa Nui came with inherent geographic disadvantages for plant survival, including few sheltered habitats with steep hillsides or deep ravines in which toromiro could remain hidden away from humans. The three volcanic craters on the island are the only such hiding places. In 1911, the Chilean botanist Francisco Fuentes noted that the toromiro was rare, only to be found in Rano Kau, the largest of the craters. The Swedish botanist Carl Skottsberg, who also worked on Hawaiian flora, visited Rano Kau in 1917 and found only a single specimen.

A compelling global exploration of nature and survival as seen through a dozen species of trees.

The final contact with the tree on its native soil occurred when the Norwegian explorer Thor Heyerdahl collected seeds from the last surviving example. This was likely the same tree that Skottsberg had found in the shelter of Rano Kau. The egg-shaped crater is about a mile across and has its own microclimate, largely out of the winds and weather, and protected from grazing ungulates by a rock formation. Foot traffic remained down in the last century, as little else lives in the crater that can be harvested or cut down. Innumerable swampy pockets of water make the area difficult to traverse. A beautiful, multicolored, shallow lake of open water and floating mats of peat cover much of the bottom of the crater. There, the tiny toromiro held on.

Heyerdahl, who had already been traveling around the Pacific Ocean in the 1940s, became famous, or infamous, for floating a radical new theory: that the islands in the Pacific had been populated initially by American Indians from the mainland of South America, rather than by people from Asia or from other Polynesian islands. In 1947, he launched an expedition with a primitive raft named Kon-Tiki and made a 5,000-mile journey, heading west from Peru.

What’s often lost in the voluminous writings about Heyerdahl and his oceanfaring obsessions was his interest in Rapa Nui. Björn Aldén, a Swedish botanist with the Gothenburg Botanical Garden, became friends with Heyerdahl and has worked to return the toromiro to its native land. In a letter to Björn, Heyerdahl decried the “tankelöse treskjaerere,” or “thoughtless woodcutters.” He noted how good it felt to have helped to save the species by collecting a handful of seeds that hung from the tree’s sole remaining branch. Heyerdahl couldn’t recount the exact date, or even the year, but thought it was sometime in late 1955 or early 1956. Heyerdahl handed the seeds off to paleobotanist Olaf Selling in Stockholm. They went to Gothenburg from there.

Locals have a strain of national pride in Gothenburg for their role in the tree’s cultivation and survival. But recently, researchers in Chile discovered that another botanist preceded Heyerdahl in getting seeds off the island. Efraín Volosky Yadlin, an Argentinian-born immigrant, participated in the first agronomic studies on Rapa Nui. Sent there by the Chilean Ministry of Agriculture in the early 1950s, Volosky Yadlin collected seeds, apparently from the same tree that Heyerdahl would come upon a few years later, and proceeded to carry out his own propagation tests on the toromiro.

Now the tree remains far afield, surviving in about a dozen locations around the world, mostly in botanical gardens including in Chile, in London and in southern France. Ultimately, researchers want to return the toromiro to Rapa Nui. But the tree still confronts challenges to surviving on its native ground, including a lack of genetic diversity and degraded soil on Rapa Nui. Past efforts to reestablish the tree have failed, but botanists are doing their best to overcome these hurdles. More studies will help researchers understand just what it will take to help the tree take root back on Rapa Nui and successfully end a long and difficult voyage.

Excerpted from Twelve Trees: The Deep Roots of Our Future by Daniel Lewis. Published by Avid Reader Press / Simon & Schuster. Copyright © 2024. All rights reserved.

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UN livestock emissions report seriously distorted our work, say experts

Exclusive: Study released at Cop28 misused research to underestimate impact of cutting meat eating, say academicsA flagship UN report on livestock emissions is facing calls for retraction from two key experts it cited who say that the paper “seriously distorted” their work.The UN Food and Agriculture Organization (FAO) misused their research to underestimate the potential of reduced meat intake to cut agricultural emissions, according to a letter sent to the FAO by the two academics, which the Guardian has seen. Continue reading...

A flagship UN report on livestock emissions is facing calls for retraction from two key experts it cited who say that the paper “seriously distorted” their work.The UN Food and Agriculture Organization (FAO) misused their research to underestimate the potential of reduced meat intake to cut agricultural emissions, according to a letter sent to the FAO by the two academics, which the Guardian has seen.Paul Behrens, an associate professor at Leiden University and Matthew Hayek, an assistant professor at New York University, both accuse the FAO study of systematic errors, poor framing, and highly inappropriate use of source data.Hayek told the Guardian: “The FAO’s errors were multiple, egregious, conceptual and all had the consequence of reducing the emissions mitigation possibilities from dietary change far below what they should be. None of the mistakes had the opposite effect.”Agriculture accounts for 23% of global greenhouse gas emissions, most of which are attributable to livestock in the form of methane from burps and manure, and deforestation for grazing and feed crops. As global meat production leapt by 39% in the first two decades of this century, agricultural emissions also rose by 14%.At the Cop28 climate summit in December, the FAO published the third in a series of studies of the livestock emissions problem. As well as reducing the FAO’s estimate of livestock’s contribution to overall global heating for a third consecutive time, it used a paper written by Behrens and others in 2017 to argue that shifts away from meat eating could only reduce global agri-food emissions by between 2 and 5%.Behrens’s paper from 2017 assessed the environmental impacts of government-backed nationally recommended diets (NRDs) of the time, which have since become outdated. Many countries, such as China and Denmark, have drastically reduced their recommended meat intake since then, while Germany now proposes a 75% plant-based diet in its NRD.Behrens says “voluminous evidence” from larger environmental reports which recommended reductions in meat content, such as the Eat-Lancet Planetary Health Diet, were ignored, according to the letter.“The scientific consensus at the moment is that dietary shifts are the biggest leverage we have to reduce emissions and other damage caused by our food system,” Behrens told the Guardian. “But the FAO chose the roughest and most inappropriate approach to their estimates and framed it in a way that was very useful for interest groups seeking to show that plant-based diets have a small mitigation potential compared to alternatives.”Of more than 200 climate scientists surveyed by Behrens and Hayek for a recent paper, 78% said it was important for livestock herd sizes to peak by 2025 if the world was to stand a chance of preventing dangerous global heating.As well as using obsolete NRDs, the scientists say the FAO report “systematically underestimates” the emissions-cutting potential of dietary shifts through what the letter calls a “series of methodological errors”.The authors say these include: double-counting meat emissions until 2050, mixing different baseline years in analyses, and channelling data inputs that inappropriately favour diets allowing increased global meat consumption. The FAO paper also skips over the opportunity cost of carbon sequestration on non-farmed land.Hayek said the FAO inappropriately cited a report he co-authored that measured all agri-food emissions, and applied it to livestock emissions alone. “It wasn’t just like comparing apples to oranges,” he said. “It was like comparing really small apples to really big oranges.”Correspondingly, the mitigation potential from farming less livestock was underestimated by a factor of between 6 and 40, he said.The FAO is the world’s primary source for agricultural data, and its reports are routinely used by authoritative bodies such as the UN’s Intergovernmental Panel on Climate Change (IPCC). But the FAO is also mandated to increase livestock productivity so as to bolster nutrition and food security, arguably creating a conflict of interests.Former officials have accused the FAO of censoring and sabotaging their work when it challenged livestock industry positions. A recent FAO roadmap to making the sector sustainable also omitted the option of reducing meat intake from a list of 120 policy interventions.That paper received praise from meat industry lobbyists, one of whom called it “music to our ears” when it was released at Cop28.An FAO spokesperson said: “As a knowledge-based organisation, FAO is fully committed to ensuring accuracy and integrity in scientific publications, especially given the significant implications for policymaking and public understanding.“We would like to assure you that the report in question has undergone a rigorous review process with both an internal and external double-blind peer review to ensure that the research meets the highest standards of quality and accuracy, and that potential biases are minimised. FAO will look into the issues raised by the academics and undertake a technical exchange of views with them.”

New analysis warns of pesticide residues on some fruits and veggies

This story was originally published in The New Lede, a journalism project of the Environmental Working Group, and is republished here with permission.Several types of fruits and vegetables generally considered to be healthy can contain levels of pesticide residues potentially unsafe for consumption, according to an analysis conducted by Consumer Reports (CR) released on Thursday.The report, which is based on seven years of data gathered by the U.S. Department of Agriculture (USDA) as part of its annual pesticide residue reporting program, concluded that 20% of 59 different fruit and vegetable categories included in the analysis carried residue levels that posed “significant risks” to consumers of those foods.Those high-risk foods included bell peppers, blueberries, green beans, potatoes and strawberries, according to CR. The group found that some green beans even had residues of an insecticide called acephate, which has been banned for use on green beans by U.S. regulators since 2011. In one sample from 2022, levels of methamidophos (a breakdown product of acephate), were morethan 100 times the level CR scientists consider safe. In another sample, acephate levels were 7 times higher than CR considers safe.Overall, out of the nearly 30,000 total fruit and vegetable samples for which CR examined data, about 8% percent were deemed to have residues at “high risk or very high risk”. Imported produce was more likely to carry high levels of pesticide residues than domestically supplied foods, the report said, noting that residue levels can vary widely from sample to sample.The results “raise red flags,” according to CR. The report advises that children and pregnant women should consume less than a serving a day of high-risk fruits and vegetables, and less than half a serving per day of “very high-risk ones.”“People need to be concerned because we see that the more data we gather on pesticides, the more we realize the levels that we previously thought to be safe turn out not to be,” said Michael Hansen, a senior scientist at CR who was recently appointed to a USDA food safety advisory committee.The organization said the “good news” is that the data showed residues in most of the foods sampled, including 16 of 25 fruit categories and 21 of 34 vegetable types, presented “little to worry about.” Nearly all organic samples showed no concerning levels of pesticide residues.The report suggests consumers “try snap peas instead of green beans, cantaloupe in place of watermelon, cabbage or dark green lettuces for kale, and the occasional sweet potato instead of a white one.”Faulty safety assurances  In coming to its findings, CR said it analyzed USDA residue test results for 29,643 individual food samples and then rated the risk of each fruit or vegetable based on how many different pesticides were found in each, how frequently and at what levels the residues were found, and the toxicity for each pesticide detected.For pesticides known to be cancer-causing, neurotoxins or endocrine disruptors – chemicals that can alter the hormonal functions – CR added an extra safety margin requirement to the levels considered safe. “People need to be concerned because we see that the more data we gather on pesticides, the more we realize the levels that we previously thought to be safe turn out not to be." Michael Hansen, Consumer Reports The CR said its safety levels differ from those set by the Environmental Protection Agency (EPA), which establishes “maximum residue limits” (MRLs) for each crop use of a pesticide after developing a risk assessment that the agency says considers multiple factors, including aggregate exposure from the pesticides, cumulative effects of related pesticides, and potential increased increased susceptibility to infants and children. Based on the EPA’s MRLs, the USDA said in its most recent pesticide data program report that 99% of foods tested had residues within the safety limits. But the EPA’s limits are too high to be truly protective of public health, and do not adequately account for the risks associated with some pesticides, according to CR.“EPA stands by its comprehensive pesticide assessment and review process to ensure the safety of the U.S. food supply,” the agency said in a statement. “Since the pesticide registration review program started in 2006, EPA has cancelled some or all uses in nearly 25% of the conventional pesticide cases it has completed work on, where new science indicates a need for additional mitigations.” The EPA says it considers “all relevant data” in making human health risk assessments for pesticide use. It is common for many farmers to apply a range of pesticides, including herbicides, insecticides and fungicides, on their fields as a means to fight weeds, bugs and plant diseases. In some cases, they spray the chemicals directly over growing plants. Residues of these chemicals are found not only in food but often in drinking water as well. Both the Food and Drug Administration and the USDA have been tracking levels of pesticide residues in foods for decades, and have repeatedly assured the public that those residues are not a human health risk as long as they do not exceed the EPA’s MRLs. But those assurances have proven wrong in the past. In one example, the government long said the insecticide chlorpyrifos was safe to be used on food if residues were within the EPA’s established limits, despite strong scientific evidence that exposure could harm the brains and nervous systems of developing children.In 2015, after decades of use in agriculture, the EPA changed its stance, saying it could not determine if chlorpyrifos in the diet was actually safe, and proposed banning the pesticide from use in farming. It took until 2021 for the agency to issue a final rule banning the pesticide, and a court challenge to the ban has kept the chemical in use.Further undermining faith in the government’s assurance on pesticide residues is the fact that the EPA consults with the companies selling the chemicals in setting allowable residue levels, and those allowable levels can be increased at the request of the companies. The EPA has approved several increases allowed for residues of the weed killing chemical glyphosate, for instance. Glyphosate, the active ingredient in Roundup herbicides, is classified as a probable human carcinogen by the International Agency for Research on Cancer but the EPA considers it not likely to cause cancer.Industry influenceThe Food Quality Protection Act (FQPA) requires the EPA to apply an additional tenfold safety margin to allowable exposure levels to account for the effects on vulnerable infants and children, and allows the agency to skip adding the safety margin “only if it will be safe for infants and children.” The agency has declined to apply that additional tenfold margin of safety for infants and children when setting the legal levels for several pesticide residues, however, even when scientists have said it is needed.Pesticide manufacturers have successfully pushed the EPA not to apply the extra safety margin for dozens of pesticides that have “clear potential to damage DNA or disrupt development,” said Chuck Benbrook, a pesticide residue expert and a consultant on the CR report. “EPA has known about the existence of thousands of excessively high tolerances since the 2000s,” said Benbrook. “Despite the powerful new tools and mandate in the FQPA to lower or revoke them, the pesticide industry makes it very difficult for the EPA to lower tolerances and progress has slowed to a crawl. Even worse, some very-high pesticides are finding their way back on the market and into children’s food.”Government and industry assurances about the safety of pesticide residues in the U.S. food supply are based on the fact that most residues in food are below the applicable tolerance levels, Benbrook added.“But we now know, and can specifically identify hundreds of samples of food each year with below-tolerance residues that pose risks far above what the EPA regards as safe,” he said.“Action needs to be taken”The CR report says the dangers lurking on grocery stores shelves could be reduced by the elimination of two chemical classes – organophosphates and carbamates. While organophosphates are used in plastic and solvent manufacturing as well as pesticides, they are also constituents of nerve gas, and exposure – acute and long-term – can have a range of harmful impacts on people and animals. “EPA has known about the existence of thousands of excessively high tolerances since the 2000s." - Charles Benbrook, a pesticide residue expert and Consumer Reports consultant As the Illinois Department of Public Health explains: “Organophosphates kill insects by disrupting their brains and nervous systems. Unfortunately, these chemicals also can harm the brains and nervous systems of animals and humans.”Carbamates bear a chemical similarity to organophosphate pesticides.The CR report comes as many scientists have increasingly been questioning whether or not a steady diet of pesticide residues can actually be safe for people and what long-term consumption of trace amounts of pesticides in food could be doing to human and animal health.“The data is showing more and more that these lower levels are having an impact,” said Hansen. “That is why some action needs to be taken.”

This story was originally published in The New Lede, a journalism project of the Environmental Working Group, and is republished here with permission.Several types of fruits and vegetables generally considered to be healthy can contain levels of pesticide residues potentially unsafe for consumption, according to an analysis conducted by Consumer Reports (CR) released on Thursday.The report, which is based on seven years of data gathered by the U.S. Department of Agriculture (USDA) as part of its annual pesticide residue reporting program, concluded that 20% of 59 different fruit and vegetable categories included in the analysis carried residue levels that posed “significant risks” to consumers of those foods.Those high-risk foods included bell peppers, blueberries, green beans, potatoes and strawberries, according to CR. The group found that some green beans even had residues of an insecticide called acephate, which has been banned for use on green beans by U.S. regulators since 2011. In one sample from 2022, levels of methamidophos (a breakdown product of acephate), were morethan 100 times the level CR scientists consider safe. In another sample, acephate levels were 7 times higher than CR considers safe.Overall, out of the nearly 30,000 total fruit and vegetable samples for which CR examined data, about 8% percent were deemed to have residues at “high risk or very high risk”. Imported produce was more likely to carry high levels of pesticide residues than domestically supplied foods, the report said, noting that residue levels can vary widely from sample to sample.The results “raise red flags,” according to CR. The report advises that children and pregnant women should consume less than a serving a day of high-risk fruits and vegetables, and less than half a serving per day of “very high-risk ones.”“People need to be concerned because we see that the more data we gather on pesticides, the more we realize the levels that we previously thought to be safe turn out not to be,” said Michael Hansen, a senior scientist at CR who was recently appointed to a USDA food safety advisory committee.The organization said the “good news” is that the data showed residues in most of the foods sampled, including 16 of 25 fruit categories and 21 of 34 vegetable types, presented “little to worry about.” Nearly all organic samples showed no concerning levels of pesticide residues.The report suggests consumers “try snap peas instead of green beans, cantaloupe in place of watermelon, cabbage or dark green lettuces for kale, and the occasional sweet potato instead of a white one.”Faulty safety assurances  In coming to its findings, CR said it analyzed USDA residue test results for 29,643 individual food samples and then rated the risk of each fruit or vegetable based on how many different pesticides were found in each, how frequently and at what levels the residues were found, and the toxicity for each pesticide detected.For pesticides known to be cancer-causing, neurotoxins or endocrine disruptors – chemicals that can alter the hormonal functions – CR added an extra safety margin requirement to the levels considered safe. “People need to be concerned because we see that the more data we gather on pesticides, the more we realize the levels that we previously thought to be safe turn out not to be." Michael Hansen, Consumer Reports The CR said its safety levels differ from those set by the Environmental Protection Agency (EPA), which establishes “maximum residue limits” (MRLs) for each crop use of a pesticide after developing a risk assessment that the agency says considers multiple factors, including aggregate exposure from the pesticides, cumulative effects of related pesticides, and potential increased increased susceptibility to infants and children. Based on the EPA’s MRLs, the USDA said in its most recent pesticide data program report that 99% of foods tested had residues within the safety limits. But the EPA’s limits are too high to be truly protective of public health, and do not adequately account for the risks associated with some pesticides, according to CR.“EPA stands by its comprehensive pesticide assessment and review process to ensure the safety of the U.S. food supply,” the agency said in a statement. “Since the pesticide registration review program started in 2006, EPA has cancelled some or all uses in nearly 25% of the conventional pesticide cases it has completed work on, where new science indicates a need for additional mitigations.” The EPA says it considers “all relevant data” in making human health risk assessments for pesticide use. It is common for many farmers to apply a range of pesticides, including herbicides, insecticides and fungicides, on their fields as a means to fight weeds, bugs and plant diseases. In some cases, they spray the chemicals directly over growing plants. Residues of these chemicals are found not only in food but often in drinking water as well. Both the Food and Drug Administration and the USDA have been tracking levels of pesticide residues in foods for decades, and have repeatedly assured the public that those residues are not a human health risk as long as they do not exceed the EPA’s MRLs. But those assurances have proven wrong in the past. In one example, the government long said the insecticide chlorpyrifos was safe to be used on food if residues were within the EPA’s established limits, despite strong scientific evidence that exposure could harm the brains and nervous systems of developing children.In 2015, after decades of use in agriculture, the EPA changed its stance, saying it could not determine if chlorpyrifos in the diet was actually safe, and proposed banning the pesticide from use in farming. It took until 2021 for the agency to issue a final rule banning the pesticide, and a court challenge to the ban has kept the chemical in use.Further undermining faith in the government’s assurance on pesticide residues is the fact that the EPA consults with the companies selling the chemicals in setting allowable residue levels, and those allowable levels can be increased at the request of the companies. The EPA has approved several increases allowed for residues of the weed killing chemical glyphosate, for instance. Glyphosate, the active ingredient in Roundup herbicides, is classified as a probable human carcinogen by the International Agency for Research on Cancer but the EPA considers it not likely to cause cancer.Industry influenceThe Food Quality Protection Act (FQPA) requires the EPA to apply an additional tenfold safety margin to allowable exposure levels to account for the effects on vulnerable infants and children, and allows the agency to skip adding the safety margin “only if it will be safe for infants and children.” The agency has declined to apply that additional tenfold margin of safety for infants and children when setting the legal levels for several pesticide residues, however, even when scientists have said it is needed.Pesticide manufacturers have successfully pushed the EPA not to apply the extra safety margin for dozens of pesticides that have “clear potential to damage DNA or disrupt development,” said Chuck Benbrook, a pesticide residue expert and a consultant on the CR report. “EPA has known about the existence of thousands of excessively high tolerances since the 2000s,” said Benbrook. “Despite the powerful new tools and mandate in the FQPA to lower or revoke them, the pesticide industry makes it very difficult for the EPA to lower tolerances and progress has slowed to a crawl. Even worse, some very-high pesticides are finding their way back on the market and into children’s food.”Government and industry assurances about the safety of pesticide residues in the U.S. food supply are based on the fact that most residues in food are below the applicable tolerance levels, Benbrook added.“But we now know, and can specifically identify hundreds of samples of food each year with below-tolerance residues that pose risks far above what the EPA regards as safe,” he said.“Action needs to be taken”The CR report says the dangers lurking on grocery stores shelves could be reduced by the elimination of two chemical classes – organophosphates and carbamates. While organophosphates are used in plastic and solvent manufacturing as well as pesticides, they are also constituents of nerve gas, and exposure – acute and long-term – can have a range of harmful impacts on people and animals. “EPA has known about the existence of thousands of excessively high tolerances since the 2000s." - Charles Benbrook, a pesticide residue expert and Consumer Reports consultant As the Illinois Department of Public Health explains: “Organophosphates kill insects by disrupting their brains and nervous systems. Unfortunately, these chemicals also can harm the brains and nervous systems of animals and humans.”Carbamates bear a chemical similarity to organophosphate pesticides.The CR report comes as many scientists have increasingly been questioning whether or not a steady diet of pesticide residues can actually be safe for people and what long-term consumption of trace amounts of pesticides in food could be doing to human and animal health.“The data is showing more and more that these lower levels are having an impact,” said Hansen. “That is why some action needs to be taken.”

Solomon Islands tribes generate income by selling carbon credits

In the Solomon Islands, Indigenous tribes are leveraging the lucrative carbon credit market to sustainably protect their ancient rainforests from logging while funneling vital income to their communities.Jo Chandler reports for Yale E360.In short:Several Solomon Islands tribes have united to form the Babatana Rainforest Conservation Project, preserving their forests and selling carbon credits internationally.The project includes verified protected areas and employs local tribespeople as rangers, enhancing biodiversity and environmental stewardship.The initiative provides significant economic benefits to the tribes, supporting community developments like education and infrastructure.Key quote:"If we misuse or destroy this land, we will not have any other,"— Linford Pitatamae, leader of the Sirebe tribeWhy this matters:Natural habitats play a significant role in the carbon market because of their ability to sequester carbon naturally. By valuing the carbon stored in these ecosystems, the market incentivizes their preservation. For example, a forest that might otherwise be cleared for agriculture could be maintained as a carbon sink. The revenue from selling carbon credits can make conservation financially viable for landowners and communities, providing an economic alternative to destructive practices like deforestation.Researchers say "proforestation" policies are the fastest and most effective way to draw excess CO2 out of the atmosphere.

In the Solomon Islands, Indigenous tribes are leveraging the lucrative carbon credit market to sustainably protect their ancient rainforests from logging while funneling vital income to their communities.Jo Chandler reports for Yale E360.In short:Several Solomon Islands tribes have united to form the Babatana Rainforest Conservation Project, preserving their forests and selling carbon credits internationally.The project includes verified protected areas and employs local tribespeople as rangers, enhancing biodiversity and environmental stewardship.The initiative provides significant economic benefits to the tribes, supporting community developments like education and infrastructure.Key quote:"If we misuse or destroy this land, we will not have any other,"— Linford Pitatamae, leader of the Sirebe tribeWhy this matters:Natural habitats play a significant role in the carbon market because of their ability to sequester carbon naturally. By valuing the carbon stored in these ecosystems, the market incentivizes their preservation. For example, a forest that might otherwise be cleared for agriculture could be maintained as a carbon sink. The revenue from selling carbon credits can make conservation financially viable for landowners and communities, providing an economic alternative to destructive practices like deforestation.Researchers say "proforestation" policies are the fastest and most effective way to draw excess CO2 out of the atmosphere.

New Research Reveals Why You Should Always Refrigerate Lettuce

Leafy greens are valuable for their dietary fiber and nutrients, yet they may also carry dangerous pathogens. Lettuce, in particular, has frequently been linked to...

A new study explores E. coli contamination in leafy greens, finding that factors like temperature and leaf characteristics affect susceptibility. Lettuce is particularly vulnerable, but kale and collards show promise as less susceptible options due to their natural antimicrobial properties when cooked.Leafy greens are valuable for their dietary fiber and nutrients, yet they may also carry dangerous pathogens. Lettuce, in particular, has frequently been linked to foodborne illness outbreaks in the U.S. A recent study from the University of Illinois Urbana-Champaign investigates the factors influencing E. coli contamination in five different types of leafy greens: romaine lettuce, green-leaf lettuce, spinach, kale, and collard greens.“We are seeing a lot of outbreaks on lettuce, but not so much on kale and other brassica vegetables. We wanted to learn more about the susceptibility of different leafy greens,” said lead author Mengyi Dong, now a postdoctoral research associate at Duke University. Dong conducted the research as a doctoral student in the Department of Food Science and Human Nutrition (FSHN), part of the College of Agricultural, Consumer, and Environmental Sciences (ACES) at the U. of I.Findings on Temperature and Leaf Surface ImpactThe researchers infected whole leaves from each of the five vegetables with E. coli O157:H7 and observed what happened after storage at 4° C (39° F), 20° C (68° F), and 37° C (98.6° F). Overall, they found that susceptibility was determined by a combination of temperature and leaf surface properties such as roughness and the natural wax coating. “At room temperature or higher, E. coli grows very fast on lettuce, but if lettuce is refrigerated at 4° C (39° F), we see a sharp decline in the E. coli population. However, for waxy greens like kale and collard, we get the opposite results. On these vegetables, E. coli grows slower under warmer temperatures, but if it is already present, it can survive longer under refrigeration.”Even so, kale and collard are overall less susceptible to E. coli contamination than lettuce. Furthermore, these vegetables are usually cooked – which kills or inactivates E. coli – while lettuce is consumed raw. Rinsing lettuce does help, Dong said, but doesn’t remove all the bacteria because of their tight attachment to the leaf.The researchers also inoculated cut leaves with E. coli O157:H7 to compare the intact surface of a whole leaf to the damaged surface of a cut leaf.“Whole leaves and freshly cut leaves present different situations. When the leaf is cut, it releases vegetable juice, which contains nutrients that stimulate bacterial growth,” Dong explained. However, the researchers found that spinach, kale, and collard juice actually exhibited antimicrobial properties that protect against E. coli.Potential Applications and ConclusionsTo further explore these findings, they isolated juice (lysate) from kale and collards and applied the liquid to lettuce leaves, finding that it can be used as a natural antimicrobial agent. The potential applications could include antimicrobial spray or coating to control foodborne pathogen contaminations at both pre-harvest and post-harvest stages, the researchers said.“We can’t completely avoid pathogens in food. Vegetables are grown in soil, not in a sterile environment, and they will be exposed to bacteria,” said co-author Pratik Banerjee, associate professor in FSHN and Illinois Extension specialist.“It’s a complex problem to solve, but we can embrace best practices in the food industry and food supply chain. There’s a lot of interest from the research community and federal agencies to address these issues, and the USDA imposes high standards for food production, so overall the U.S. food supply is quite safe.”Banerjee and Dong emphasize they do not want to discourage people from eating fresh fruit and vegetables; they are part of a healthy diet. Just follow food safety guidelines, wash your lettuce thoroughly, store it in the refrigerator, and pay attention to any food safety recalls in your area, they conclude.Reference: “Fates of attached E. coli o157:h7 on intact leaf surfaces revealed leafy green susceptibility” by Mengyi Dong, Maxwell J. Holle, Michael J. Miller, Pratik Banerjee and Hao Feng, 28 November 2023, Food Microbiology.DOI: 10.1016/j.fm.2023.104432This project was supported by the USDA Specialty Crop Block Grant Program (SCBGP) through the Illinois Department of Agriculture [grant numbers IDOA SC-22-20].

NASA’s Artemis Astronauts Will Help Grow Crops on the Moon—And Much More

When astronauts return to the moon later this decade, they’ll bring along science experiments to study moonquakes, lunar water ice and extraterrestrial agriculture

In the not-too-distant future, American astronauts will once again set foot on the moon’s silvery desolation. Instead of brief jaunts around the low-latitude frozen lava seas on the orb’s Earth-facing hemisphere like their Apollo-era forebears, however, the moonwalkers of NASA’s Artemis III mission will be targeting the lunar south pole—a region that holds ancient deposits of water and, just possibly, the future site of a permanent astronaut outpost. The mission will have a crew of four, but two will remain in lunar orbit while the other pair touches down on the southern polar region and scoots briefly across the surface. And as they do so, they will deploy a suite of scientific instruments to forensically examine what will then be the most important parcel of off-world real estate in the solar system.After considering myriad proposals, NASA has now announced three gadgets chosen to accompany the Artemis III crew members on their voyage: The Lunar Environment Monitoring Station (LEMS) package is a remarkably precise seismometer that is designed to listen out for moonquakes and survey the lunar geological underworld. The Lunar Effects on Agricultural Flora (LEAF) instrument will attempt to grow three crops on the moon and study how they respond to the mercurial, extreme environment. And the Lunar Dielectric Analyzer (LDA) will use the flow of electric currents through the lunar soil to detect the presence of volatiles, most notably water ice.These three instruments are not guaranteed to find their way to the lunar south pole. Additional developmental work is required to ensure each can fulfill its scientific objectives and to quadruple-check that all are compatible with Artemis III’s launch architecture and carefully choreographed surface excursions. But the signal NASA wishes to broadcast with this tentative selection of doodads is already loud and clear: more than a half-century after the flash and fade of Apollo, the U.S. is returning to the moon for the long haul.On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.“We want Artemis to be sustainable,” says Noah Petro, Artemis III’s project scientist.Establishing a bona fide moon base requires ascertaining several things: the risk to structures from moonquakes, the possibility of growing plants on the moon and the likelihood of finding water to use there. This trio of instruments will seek answers to those practical queries while conducting basic scientific investigations on the moon’s scarcely explored far side. “We’ve got this great scientific story to tell,” Petro says. And if all three work wonders, “we are going to be setting a precedent that other missions will have to meet.”Shaking and QuakingSophisticated scientific instrumentation is no stranger to the lunar surface, which now hosts a surprisingly diverse array of experiments sent there with ever increasing cadence over the past few years by multiple space agencies and spaceflight companies. But wonky landings and straight-up crashes have produced decidedly mixed results for these ventures, which all relied on automated robotic deployments.Using astronauts to unpack and set up experimental apparatuses is far more expensive yet also has a far superior track record of success. “The added advantage of having people there is that you get a little bit more flexibility,” says Ben Fernando, a seismologist at Johns Hopkins University. “People can debug things.” And of course, you can ensure that the experiments are as close to their optimal locations and configurations as humanly possible—something of paramount importance to LEMS, which is one of the most precise and sensitive seismometers ever developed.LEMS is actually a pair of seismometers, each of which will be used to detect two different types of seismic rumbles. One will be inserted into a borehole, while the other will be put into an excavated ditch. Because astronauts will place them, both are nigh guaranteed to be perfectly coupled with the ground and shielded from an excess of environmental surface noise.It may sound absurd that digging holes is a key reason astronauts are required to deploy these seismometers. Robots have had a famously difficult time drilling into the surprisingly resistant soils of both the moon and Mars, however. Although astronauts have found this challenging, too—the Apollo moonwalkers struggled with some of their deployments—they can troubleshoot in real time in ways no robot can (yet). “Yes, it takes enormous amounts of money to put astronauts on the moon. But if they’re there anyway, how hard is it for them to dig a trench?” says Paul Byrne, a planetary scientist at Washington University in St. Louis and a member of the LEMS team.Solar-powered by day and battery-powered by night, LEMS will gradually build up a richly detailed seismic picture of the understudied south pole. The experiment will beam its hard-won readings back to Earth once a month to add to preexisting data from Apollo-era seismometers at sites on the moon’s near side. “If it is used as planned, this thing will last for two years on the lunar surface,” Byrne says. That should be more than enough time to fill in gaps in information about the frequency of south polar moonquakes and the bulk structure of the lunar subsurface there—crucial data points for reasons of not just science but also safety.“If you want to establish a permanent settlement on the lunar south pole, you better understand the seismic state of that environment in the long term,” says Mehdi Benna, a planetary scientist at the University of Maryland, Baltimore County, and LEMS’s team leader.“I’m delighted they selected this,” says Thomas Watters, a planetary scientist at the National Air and Space Museum in Washington, D.C. Apollo-era seismometers revealed not only that the moon has sporadic temblors but that some of the most intense happened around the lunar south pole. And although Earth’s quakes can be far more powerful, “these things can last for hours on the moon, not just minutes,” Watters says. “You’ve got to be prepared for that.”Quakes aren’t the only things LEMS will detect. Car-sized space rocks burn up harmlessly in Earth’s atmosphere, whereas they plow unimpeded into the lunar surface, making them a hazard. On the moon “impacts can happen anywhere,” Fernando says—and LEMS will be able to assess the impact rate around the lunar south pole.A Farm on the MoonThe lunar south pole’s allure for human exploration comes from its nearly constant access to solar power—and also from the water ice thought to lurk in abundance within deeply shadowed craters and in the shallow subsurface. Melted and purified, that ice could be used as potable water; split into constituent hydrogen and oxygen, it could provide rocket fuel and breathable air. Yet first, scientists need to ascertain just how much H2O actually exists there to use—something that the LDA instrument will address by assessing how electric fields subtly convulse when propagating through the lunar soil.Picking an ideal deployment spot—one that experiences both day and night, for example—could be crucial for LDA’s studies. And the requisite mobility and precision are “very, very difficult for a robotic mission but probably very easy for trained astronauts,” says Hideaki Miyamoto, a planetary scientist the University of Tokyo and LDA’s team leader. Robots will still assist the effort, however: LDA’s siting will be indirectly supported by NASA’s Volatiles Investigating Polar Exploration Rover, or VIPER, which will sniff out water molecules in the south polar region after it launches later this year.But before any lunar water is used to irrigate crops for hungry astronauts, NASA’s mission planners want to ensure edible plants can even grow on the moon in the first place. That’s LEAF’s task. This instrument is essentially a space-age terrarium, featuring an enclosed growth chamber to nourish three crops—Wolffia (known as duckweed), Brassica rapa (related to turnip and bok choy plants) and Arabidopsis thaliana (thale-cress)—and protect them from the harsh lunar environment.All three well-studied model plants have been flown in space before. By taking root on the moon, however, they will enter scarcely charted agricultural realms. Once LEAF has been deployed, its seeds will be pampered with water, nutrients and light in a clement atmosphere, “much like an indoor farm does on Earth,” says LEAF’s team leader Christine Escobar, an ecologist and vice president of Space Lab Technologies in Boulder, Colo. Cameras and various sensors will monitor their growth. Some of the quickly germinating plants will be harvested for further study by the Artemis III team, while others will continue to grow until the long, cold darkness of lunar night falls.LEAF is the instrument that is most explicitly tied to the creation of a long-term presence on the lunar south pole. “Human nutrition and life support—carbon dioxide removal, oxygen production and water purification—provided by space agriculture will enable long-duration human exploration of the moon and beyond,” Escobar says.Even if LEAF’s tranquil terrarium makes a giant leap in otherworldly botany, it will be but a small step toward true lunar farming, which faces myriad challenges such as lower gravity, higher radiation levels and a dearth of high-quality soil. “Lunar regolith will likely be used for plant growth facilities in established lunar bases,” says Anna-Lisa Paul, a horticultural scientist at the University of Florida. She recently attempted to grow thale-cress in lunar soil obtained by the Apollo missions. Although the experiment was successful, the plants hated it; they were slow to develop and exhibited signs of stress. You must start somewhere, however, and what LEAF will tell botanists will be invaluable. “Based on what is discovered, the next step could be to help plants with specific difficulties either by engineering them to better enable them to physiologically adapt or [by] choosing crop species that are naturally better suited to dealing with that particular stress response,” Paul says.Altogether, NASA’s choice of these instruments further reinforces how seriously the agency is pursuing its intentions to return humans to the moon—this time, to linger and perhaps even stay. After LEMS, LDA and LEAF have done their work, Fernando says, it’ll be harder to argue against the moon as “somewhere you could, in theory, have people live for an extended period of time.”The Artemis program may have been subject to various controversies, technical challenges and budgetary overspills—but announcements like this one make the long-awaited lunar return, and NASA’s ambitions to remain there, seem that much more tangible. “We’re going to see humans on the moon. And that’s going to start changing how we view the whole enterprise,” Byrne says. “This is not going to be planting the flag and going home.”

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