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An Ancient Partnership: Unlocking the Microbial Blueprint of Earth’s Evolution

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Monday, July 22, 2024

An artist interpretation of the hazy atmosphere of Archean Earth – a pale orange dot. Credit: NASA’s Goddard Space Flight Center/Francis ReddyScientists review the extensive influence of microorganisms on Earth’s history, tracing their impact through isotopic and genetic evidence.The study highlights the connection between microbial activity and major environmental shifts, such as oxygen levels, which are crucial for understanding Earth’s evolution and assessing extraterrestrial habitability.NASA-supported scientists have examined the long and intricately linked history of microbial life and the Earth’s environment. By reviewing the current state of knowledge across fields like microbiology, molecular biology, and geology, the study looks at how microorganisms have both shaped and been shaped by chemical properties of our planet’s oceans, land, and atmosphere. The study combines data across multiple fields of study and discusses how information on the complicated history of life on our planet from a single field cannot be viewed in isolation. Understanding Microbial FossilsThe first life on Earth was microbial. Today the vast majority of our planet’s biomass is still made up of tiny, single-celled microorganisms. Although they’re abundant, the history of microbes can be a challenge for astrobiologists to study. Microbes don’t leave bones, shells or other large fossils behind like dinosaurs, fish, or other large organisms. Because of this, scientists must look at different evidence to understand the evolution of microbial life through time.Rocks along the shoreline of Lake Salda in Turkey were formed over time by microbes that trap minerals in the water. These microbialites were once a major form of life on Earth. Credit: NASA/JPL-CaltechIn order to study ancient microbes on Earth, astrobiologists look for isotopic fingerprints in rocks that can be used to identify the metabolisms of ancient communities. Metabolism refers to the conversion of food into energy, and happens in all living things. Many elements (think carbon (C), nitrogen (N), Sulfur (S), iron (Fe)) are involved in microbial metabolism. As microbes process these elements, they cause isotopic changes that scientists can spot in the rock record. Microbes also help to control how these elements are deposited and cycled in the environment, affecting geology and chemistry at both local and global scales (consider the role of microbes in the carbon cycle on Earth today).Genetic and Geological InsightsAnother way to study ancient microbial life is to look back along the evolutionary information contained in the genetics of life today. Combining this genetic information from molecular biology with geobiological information from the rock record can help astrobiologists understand the connections between the shared evolution of the early Earth and early life.For an example of geological evidence of microbial metabolism, we can consider the formation of banded iron formations (BIFs) on the ancient seafloor. These colorful layers of alternating iron- and silicon-rich sediment were formed from 3.8 billion to 1.8 billion years ago and are associated with some of the oldest rock formations on Earth. The red colors they exhibit are from their high iron content, showing us that the ocean of Earth was rich in iron during the 2 billion years in which these rocks were forming.Many microbial structures on the shores of Lake Salda in Turkey are exposed as water levels drop, allowing scientists to study relationships between life and the surrounding environment. Credit: Tim Lyons/UCRIn the new study, the team of researchers provides a review of current knowledge, gleaning information into the early metabolisms used by microbial life, the timing of when these metabolisms evolved, and how these processes are linked to major chemical and physical changes on Earth, such as the oxygenation of the oceans and atmosphere.Evolution and Oxygenation EffectsOver time, the prevalence of oxygen on Earth has varied dramatically, in the ocean, in the atmosphere, and on land. These changes impacted both the evolution of the biosphere and the environment. For instance, as the activity of photosynthetic organisms raised oxygen levels in the atmosphere, creating new environments for microbial life to inhabit. Different nutrients were made accessible to life to fuel growth. At the same time, microbes that couldn’t survive in the presence of oxygen had to adapt, perish, or find a way to survive in environments where oxygen didn’t persist, such as deep in the Earth’s subsurface.Photograph of a fossilized stromatolite in Australia. These ancient structures resulted from the activity of microorganisms that lived in layered, mat-like colonies. Credit: NASA/Mike ToillionThe new study explains our understanding of how oxygen levels have changed over time and spatial scales. The authors map different types of microbial metabolism, such as photosynthesis, to this history to better understand the “cause-and-effect relationship” between oxygen and the evolution of life on Earth. The paper provides important context for major changes in the course of evolution for the biosphere and the planet.Biogeochemical Cycles and Evolutionary ImpactsBy carefully considering the history of different types of microbial metabolisms on Earth, the review paper shows how biogeochemical cycles on our planet are inextricably linked through time over both local and global scales. The authors also discuss significant gaps in our knowledge that limit interpretations. For instance, we do not know how large the young biosphere on Earth was, which limits our ability to estimate the global effects of various metabolisms during Earth’s earliest years.Similarly, when using genetic information to look back along the tree of life, scientists can estimate when certain genes first appeared (and thereby what types of metabolisms could have been used at the time in living cells). However, the evolution of a new type of metabolism at a point in history does not necessarily mean that that metabolism was common or had a large enough effect in the environment to leave evidence in the rock record.This is an illustration of exoplanet WASP-39 b, also known as Bocaprins. NASA’s James Webb Space Telescope provided the most detailed analysis of an exoplanet atmosphere ever with WASP-39 b analysis released in November 2022. Webb’s Near-Infrared Spectrograph (NIRSpec) showed unambiguous evidence for carbon dioxide in the atmosphere, while previous observations from NASA’s Hubble and Spitzer Space Telescopes, as well as other telescopes, indicate the presence of water vapor, sodium, and potassium. The planet probably has clouds and some form of weather, but it may not have atmospheric bands like those of Jupiter and Saturn. This illustration is based on indirect transit observations from Webb as well as other space and ground-based telescopes. Webb has not captured a direct image of this planet. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)Conclusion and Implications for Extraterrestrial LifeAccording to the authors, “The history of microbial life marched in step with the history of the oceans, land and atmosphere, and our understanding remains limited by how much we still do not know about the environments of the early Earth.”The study also has wider implications in the search for life beyond Earth. Understanding the co-evolution of life and the environment can help scientists better understand the conditions necessary for a planet to be habitable. The interconnections between life and the environment also provide important clues in the search for biosignature gases in the atmospheres of planets that orbit distant stars.For more on this research, see New Insights Into Earth’s First Organisms Could Change How We Search for Extraterrestrial Life.Reference: “Co‐evolution of early Earth environments and microbial life” by Timothy W. Lyons, Christopher J. Tino, Gregory P. Fournier, Rika E. Anderson, William D. Leavitt, Kurt O. Konhauser and Eva E. Stüeken, 29 May 2024, Nature Reviews Microbiology.DOI: 10.1038/s41579-024-01044-y

Scientists review the extensive influence of microorganisms on Earth’s history, tracing their impact through isotopic and genetic evidence. The study highlights the connection between microbial...

Archean Earth Pale Orange Dot

An artist interpretation of the hazy atmosphere of Archean Earth – a pale orange dot. Credit: NASA’s Goddard Space Flight Center/Francis Reddy

Scientists review the extensive influence of microorganisms on Earth’s history, tracing their impact through isotopic and genetic evidence.

The study highlights the connection between microbial activity and major environmental shifts, such as oxygen levels, which are crucial for understanding Earth’s evolution and assessing extraterrestrial habitability.

NASA-supported scientists have examined the long and intricately linked history of microbial life and the Earth’s environment. By reviewing the current state of knowledge across fields like microbiology, molecular biology, and geology, the study looks at how microorganisms have both shaped and been shaped by chemical properties of our planet’s oceans, land, and atmosphere. The study combines data across multiple fields of study and discusses how information on the complicated history of life on our planet from a single field cannot be viewed in isolation.

Understanding Microbial Fossils

The first life on Earth was microbial. Today the vast majority of our planet’s biomass is still made up of tiny, single-celled microorganisms. Although they’re abundant, the history of microbes can be a challenge for astrobiologists to study. Microbes don’t leave bones, shells or other large fossils behind like dinosaurs, fish, or other large organisms. Because of this, scientists must look at different evidence to understand the evolution of microbial life through time.

Lake Salda in Turkey

Rocks along the shoreline of Lake Salda in Turkey were formed over time by microbes that trap minerals in the water. These microbialites were once a major form of life on Earth. Credit: NASA/JPL-Caltech

In order to study ancient microbes on Earth, astrobiologists look for isotopic fingerprints in rocks that can be used to identify the metabolisms of ancient communities. Metabolism refers to the conversion of food into energy, and happens in all living things. Many elements (think carbon (C), nitrogen (N), Sulfur (S), iron (Fe)) are involved in microbial metabolism. As microbes process these elements, they cause isotopic changes that scientists can spot in the rock record. Microbes also help to control how these elements are deposited and cycled in the environment, affecting geology and chemistry at both local and global scales (consider the role of microbes in the carbon cycle on Earth today).

Genetic and Geological Insights

Another way to study ancient microbial life is to look back along the evolutionary information contained in the genetics of life today. Combining this genetic information from molecular biology with geobiological information from the rock record can help astrobiologists understand the connections between the shared evolution of the early Earth and early life.

For an example of geological evidence of microbial metabolism, we can consider the formation of banded iron formations (BIFs) on the ancient seafloor. These colorful layers of alternating iron- and silicon-rich sediment were formed from 3.8 billion to 1.8 billion years ago and are associated with some of the oldest rock formations on Earth. The red colors they exhibit are from their high iron content, showing us that the ocean of Earth was rich in iron during the 2 billion years in which these rocks were forming.

Lake Salda Rocks

Many microbial structures on the shores of Lake Salda in Turkey are exposed as water levels drop, allowing scientists to study relationships between life and the surrounding environment. Credit: Tim Lyons/UCR

In the new study, the team of researchers provides a review of current knowledge, gleaning information into the early metabolisms used by microbial life, the timing of when these metabolisms evolved, and how these processes are linked to major chemical and physical changes on Earth, such as the oxygenation of the oceans and atmosphere.

Evolution and Oxygenation Effects

Over time, the prevalence of oxygen on Earth has varied dramatically, in the ocean, in the atmosphere, and on land. These changes impacted both the evolution of the biosphere and the environment. For instance, as the activity of photosynthetic organisms raised oxygen levels in the atmosphere, creating new environments for microbial life to inhabit. Different nutrients were made accessible to life to fuel growth. At the same time, microbes that couldn’t survive in the presence of oxygen had to adapt, perish, or find a way to survive in environments where oxygen didn’t persist, such as deep in the Earth’s subsurface.

Egg Carton Stromatolites Trendall Western Australia

Photograph of a fossilized stromatolite in Australia. These ancient structures resulted from the activity of microorganisms that lived in layered, mat-like colonies. Credit: NASA/Mike Toillion

The new study explains our understanding of how oxygen levels have changed over time and spatial scales. The authors map different types of microbial metabolism, such as photosynthesis, to this history to better understand the “cause-and-effect relationship” between oxygen and the evolution of life on Earth. The paper provides important context for major changes in the course of evolution for the biosphere and the planet.

Biogeochemical Cycles and Evolutionary Impacts

By carefully considering the history of different types of microbial metabolisms on Earth, the review paper shows how biogeochemical cycles on our planet are inextricably linked through time over both local and global scales. The authors also discuss significant gaps in our knowledge that limit interpretations. For instance, we do not know how large the young biosphere on Earth was, which limits our ability to estimate the global effects of various metabolisms during Earth’s earliest years.

Similarly, when using genetic information to look back along the tree of life, scientists can estimate when certain genes first appeared (and thereby what types of metabolisms could have been used at the time in living cells). However, the evolution of a new type of metabolism at a point in history does not necessarily mean that that metabolism was common or had a large enough effect in the environment to leave evidence in the rock record.

Exoplanet WASP-39 b and Its Star (Illustration)

This is an illustration of exoplanet WASP-39 b, also known as Bocaprins. NASA’s James Webb Space Telescope provided the most detailed analysis of an exoplanet atmosphere ever with WASP-39 b analysis released in November 2022. Webb’s Near-Infrared Spectrograph (NIRSpec) showed unambiguous evidence for carbon dioxide in the atmosphere, while previous observations from NASA’s Hubble and Spitzer Space Telescopes, as well as other telescopes, indicate the presence of water vapor, sodium, and potassium. The planet probably has clouds and some form of weather, but it may not have atmospheric bands like those of Jupiter and Saturn. This illustration is based on indirect transit observations from Webb as well as other space and ground-based telescopes. Webb has not captured a direct image of this planet. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)

Conclusion and Implications for Extraterrestrial Life

According to the authors, “The history of microbial life marched in step with the history of the oceans, land and atmosphere, and our understanding remains limited by how much we still do not know about the environments of the early Earth.”

The study also has wider implications in the search for life beyond Earth. Understanding the co-evolution of life and the environment can help scientists better understand the conditions necessary for a planet to be habitable. The interconnections between life and the environment also provide important clues in the search for biosignature gases in the atmospheres of planets that orbit distant stars.

For more on this research, see New Insights Into Earth’s First Organisms Could Change How We Search for Extraterrestrial Life.

Reference: “Co‐evolution of early Earth environments and microbial life” by Timothy W. Lyons, Christopher J. Tino, Gregory P. Fournier, Rika E. Anderson, William D. Leavitt, Kurt O. Konhauser and Eva E. Stüeken, 29 May 2024, Nature Reviews Microbiology.
DOI: 10.1038/s41579-024-01044-y

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California regulators approve rules to curb methane leaks and prevent fires at landfills

California air regulators adopted new rules designed to reduce methane leaks and better respond to disastrous underground fires at landfills statewide.

In one of the most important state environmental decisions this year, California air regulators adopted new rules designed to reduce methane leaks and better respond to disastrous underground fires at landfills statewide. California Air Resources Board members voted 12-0 on Thursday to approve a batch of new regulations for the state’s nearly 200 large landfills, designed to minimize the release of methane, a powerful greenhouse gas produced by decomposing organic waste. Landfills are California’s second-largest source of methane emissions, following only the state’s large dairy cow and livestock herds.The new requirements will force landfill operators to install additional pollution controls; more comprehensively investigate methane leaks on parts of landfills that are inaccessible with on-the-ground monitoring using new technology like drones and satellites; and fix equipment breakdowns much faster. Landfill operators also will be required to repair leaks identified through California’s new satellite-detection program. The regulation is expected to prevent the release of 17,000 metric tons of methane annually — an amount capable of warming the atmosphere as much as 110,000 gas-fired cars driven for a year. It also will curtail other harmful landfill pollution, such as lung-aggravating sulfur and cancer-causing benzene. Landfill operators will be required to keep better track of high temperatures and take steps to minimize the fire risks that heat could create. There are underground fires burning in at least two landfills in Southern California — smoldering chemical reactions that are incinerating buried garbage, releasing toxic fumes and spewing liquid waste. Regulators found explosive levels of methane emanating from many other landfills across the state.During the three-hour Air Resources Board hearing preceding the vote, several Californians who live near Chiquita Canyon Landfill — one of the known sites where garbage is burning deep underground — implored the board to act to prevent disasters in other communities across the state.“If these rules were already updated, maybe my family wouldn’t be sick,” said Steven Howse, a 27-year resident of Val Verde. “My house wouldn’t be for sale. My close friend and neighbor would still live next door to me. And I wouldn’t be pleading with you right now. You have the power to change this.”Landfill operators, including companies and local governments, voiced their concern about the costs and labor needed to comply with the regulation. “We want to make sure that the rule is implementable for our communities, not unnecessarily burdensome,” said John Kennedy, a senior policy advocate for Rural County Representatives of California, a nonprofit organization representing 40 of the state’s 58 counties, many of which own and operate landfills. “While we support the overarching goals of the rule, we remain deeply concerned about specific measures including in the regulation.”Lauren Sanchez, who was appointed chair of the California Air Resources Board in October, recently attended the United Nations’ COP30 climate conference in Brazil with Gov. Gavin Newsom. What she learned at the summit, she said, made clear to her that California’s methane emissions have international consequences, and that the state has an imperative to reduce them. “The science is clear, acting now to reduce emissions of methane and other short-lived climate pollutants is the best way to immediately slow the pace of climate change,” Sanchez said.

Exoplanet atmospheres are a key to habitability

The habitable zone of a planet might be key to whether life can survive there. But so are exoplanet atmospheres, scientists say. The post Exoplanet atmospheres are a key to habitability first appeared on EarthSky.

Artist’s concept of exoplanet GJ 9827 d. It might be a steam world, with lots of water vapor in its atmosphere. Astronomers say exoplanet atmospheres are a key to whether or not life could survive on a planet. Image via NASA/ ESA/ Leah Hustak (STScI)/ Ralf Crawford (STScI)/ University of Montreal. Scientists focus on the habitable zone (where liquid water might exist) when they are gauging whether an exoplanet could be habitable. But exoplanet atmospheres are also key to whether a planet can maintain stable, life-supporting conditions. For life to persist on a planet, the environment must be stable. A planet’s surface, oceans and atmosphere can work together to regulate the system. By Morgan Underwood, Rice University EarthSky isn’t powered by billionaires. We’re powered by you.Support EarthSky’s 2025 Donation Campaign and help keep science accessible. Exoplanet atmospheres are a key to habitability When astronomers search for planets that could host liquid water on their surface, they start by looking at a star’s habitable zone. Water is a key ingredient for life, and on a planet too close to its star, water on its surface may boil. Too far, and it could freeze. This zone marks the region in-between. But being in this sweet spot doesn’t automatically mean a planet is hospitable to life. Other factors, like whether a planet is geologically active or has processes that regulate gases in its atmosphere, play a role. The habitable zone provides a useful guide to search for signs of life on exoplanets, or planets outside our solar system orbiting other stars. But what’s in these planets’ atmospheres holds the next clue about whether liquid water – and possibly life – exists beyond Earth. The greenhouse effect On Earth, the greenhouse effect, caused by gases like carbon dioxide and water vapor, keeps the planet warm enough for liquid water and life as we know it. Without an atmosphere, Earth’s surface temperature would average around 0 degrees Fahrenheit (-18 C), far below the freezing point of water. The boundaries of the habitable zone are defined by how much of a greenhouse effect is necessary to maintain the surface temperatures that allow for liquid water to persist. It’s a balance between sunlight and atmospheric warming. Many planetary scientists, including me, are seeking to understand if the processes responsible for regulating Earth’s climate are operating on other habitable-zone worlds. We use what we know about Earth’s geology and climate to predict how these processes might appear elsewhere. That is where my geoscience expertise comes in. Picturing the habitable zone of a solar system analog, with Venus- and Mars-like planets outside of the “just right” temperature zone. Image via NASA. Why the habitable zone? The habitable zone is a simple and powerful idea, and for good reason. It provides a starting point, directing astronomers to where they might expect to find planets with liquid water. But without needing to know every detail about the planet’s atmosphere or history. Its definition is partially informed by what scientists know about Earth’s rocky neighbors. Mars, which lies just outside the outer edge of the habitable zone, shows clear evidence of ancient rivers and lakes where liquid water once flowed. Similarly, Venus is currently too close to the sun to be within the habitable zone. Yet, some geochemical evidence and modeling studies suggest Venus may have had water in its past. Though how much and for how long remains uncertain. These examples show that while the habitable zone is not a perfect predictor of habitability, it provides a useful starting point. How to have a stable environment What the habitable zone doesn’t do is determine whether a planet can sustain habitable conditions over long periods of time. On Earth, a stable climate allowed life to emerge and persist. Liquid water could remain on the surface, giving slow chemical reactions enough time to build the molecules of life. This let early ecosystems develop resilience to change, which reinforced habitability. Life emerged on Earth, but continued to reshape the environments it evolved in, making them more conducive to life. This stability likely unfolded over hundreds of millions of years, as the planet’s surface, oceans and atmosphere worked together as part of a slow but powerful system to regulate Earth’s temperature. Recycling inorganic carbon A key part of this system is how Earth recycles inorganic carbon between the atmosphere, surface and oceans over the course of millions of years. Inorganic carbon refers to carbon bound in atmospheric gases, dissolved in seawater or locked in minerals, rather than biological material. This part of the carbon cycle acts like a natural thermostat. When volcanoes release carbon dioxide into the atmosphere, the carbon dioxide molecules trap heat and warm the planet. As temperatures rise, rain and weathering draw carbon out of the air and store it in rocks and oceans. If the planet cools, this process slows down. This allows carbon dioxide, a warming greenhouse gas, to build up in the atmosphere again. This part of the carbon cycle has helped Earth recover from past ice ages and avoid runaway warming. Even as the sun has gradually brightened, this cycle has contributed to keeping temperatures on Earth within a range where liquid water and life can persist for long spans of time. Similar cycles in exoplanet atmospheres? Now, scientists are asking whether similar geological processes might operate on other planets. And if so, how they might detect them. For example, if researchers could observe enough rocky planets in their stars’ habitable zones, they could look for a pattern connecting the amount of sunlight a planet receives and how much carbon dioxide is in its atmosphere. Finding such a pattern may hint that the same kind of carbon-cycling process could be operating elsewhere. The mix of gases in a planet’s atmosphere is shaped by what’s happening on or below its surface. One study shows that measuring atmospheric carbon dioxide in a number of rocky planets could reveal whether their surfaces are broken into a number of moving plates, like Earth’s, or if their crusts are more rigid. On Earth, these shifting plates drive volcanism and rock weathering, which are key to carbon cycling. Simulation of what space telescopes, like the Habitable Worlds Observatory, will capture when looking at distant solar systems. Image via STScI/ NASA GSFC. Keeping an eye on distant exoplanet atmospheres The next step will be toward gaining a population-level perspective of planets in their stars’ habitable zones. By analyzing atmospheric data from many rocky planets, researchers can look for trends that reveal the influence of underlying planetary processes, such as the carbon cycle. Scientists could then compare these patterns with a planet’s position in the habitable zone. Doing so would allow them to test whether the zone accurately predicts where habitable conditions are possible, or whether some planets maintain conditions suitable for liquid water beyond the zone’s edges. This kind of approach is especially important given the diversity of exoplanets. Many exoplanets fall into categories that don’t exist in our solar system. These include super Earths and mini Neptunes. Others orbit stars smaller and cooler than the sun. NASA’s Habitable Worlds Observatory The datasets needed to explore and understand this diversity are just on the horizon. NASA’s upcoming Habitable Worlds Observatory will be the first space telescope designed specifically to search for signs of habitability and life on planets orbiting other stars. It will directly image Earth-sized planets around sunlike stars to study their atmospheres in detail. Instruments on the observatory will analyze starlight passing through these atmospheres to detect gases like carbon dioxide, methane, water vapor and oxygen. As starlight filters through a planet’s atmosphere, different molecules absorb specific wavelengths of light, leaving behind a chemical fingerprint that reveals which gases are present. These compounds offer insight into the processes shaping these worlds. The Habitable Worlds Observatory is under active scientific and engineering development, with a potential launch targeted for the 2030s. Combined with today’s telescopes, which are increasingly capable of observing atmospheres of Earth-sized worlds, scientists may soon be able to determine whether the same planetary processes that regulate Earth’s climate are common throughout the galaxy, or uniquely our own. NASA’s planned Habitable Worlds Observatory will look for exoplanets that could potentially host life. Morgan Underwood, Ph.D. Candidate in Earth, Environmental and Planetary Sciences, Rice University This article is republished from The Conversation under a Creative Commons license. Read the original article. Bottom line: The habitable zone of a planet might be key to whether life can survive there. But so are exoplanet atmospheres, scientists say.The post Exoplanet atmospheres are a key to habitability first appeared on EarthSky.

Some California landfills are on fire and leaking methane. Newly proposed rules could make them safer

California is considering adopting new rules to better identify and more quickly to respond to dangerous methane leaks and underground fires at landfills statewide.

A vast canyon of buried garbage has been smoldering inside a landfill in the Santa Clarita Valley, inducing geysers of liquid waste onto the surface and noxious fumes into the air.In the Inland Empire, several fires have broken out on the surface of another landfill. In the San Fernando Valley, an elementary school has occasionally canceled recess due to toxic gases emanating from rain-soaked, rotting garbage from a nearby landfill. And, in the San Francisco Bay Area, burrowing rodents may be digging into entombed trash at a landfill-turned-park, unloosing explosive levels of methane.These are just a few of the treacherous episodes that have recently transpired at landfills in California, subjecting the state’s waste management industry to growing scrutiny by residents and regulators.Landfill emissions — produced by decaying food, paper and other organic waste — are a major source of planet-warming greenhouse gases and harmful air pollution statewide. But mismanagement, aging equipment and inadequate oversight have worsened this pollution in recent years, according to environmental regulators and policy experts.This week, the California Air Resources Board will vote on adopting a new slate of requirements to better identify and more quickly respond to methane leaks and disastrous underground fires at large landfills statewide.The proposal calls for using satellites, drones and other new technologies to more comprehensively investigate methane leaks. It also would require landfill operators to take corrective action within a few days of finding methane leaks or detecting elevated temperatures within their pollution control systems.In recent years, state regulators have pinpointed at least two landfills in Southern California experiencing “rare” underground landfill fires — largely uncontrollable disasters that have burned troves of buried garbage and released toxic fumes into the air. More recently, a new state satellite program has detected 17 methane plumes from nine landfills between July and October, potentially leaking the flammable gas into unwanted areas and contributing to climate change.Proponents of the proposed rule say the added oversight could help reduce California’s second-largest source of methane, a potent greenhouse gas that warms the atmosphere much more than carbon dioxide. It could also bring relief to hundreds of thousands of people who live nearby landfills and may be exposed to toxic pollutants like hydrogen sulfide or benzene.“Curbing methane emissions is a relatively quick and cost-effective way to reduce the greenhouse pollution that’s wreaking havoc with our climate,” said Bill Magavern, policy director at the Coalition for Clean Air. “But [we’ve] also been involved in updating and strengthening the rule because we’re seeing the community impacts of leaking landfills, particularly at places like Chiquita Canyon, where we have a landfill fire that is making people in the community sick.”Nearly 200 landfills statewide would be subject to the proposed requirements — 48 are privately owned and 140 are government-owned.Many landfill operators oppose the rule, saying the new requirements would saddle the industry with an untenable workload and millions of dollars each year in added costs. These costs could be passed on to residents, whose garbage fees have already risen significantly in recent years.Sacramento County officials, who operate the Kiefer Landfill, said the proposed protocols were not feasible. “As a public landfill, Kiefer cannot quickly adapt to regulatory shifts of this magnitude, and these increased costs would ultimately burden the community it serves,” Sacramento County officials wrote in a Nov. 10 letter to the state Air Resources Board.The vast majority of landfills are already required to monitor for leaks and operate a gas collection system — a network of wells that extend deep into the layers of buried waste to capture and destroy methane.A hot messChiquita Canyon Landfill in Castaic has become the poster child for the issues plaguing California’s waste management system.A blistering-hot chemical reaction began inside the landfill’s main canyon in May 2022, roasting garbage in a roughly 30-acre area.Starting in April 2023, residents of Castaic and nearby Val Verde began to take notice. They called in thousands of odor complaints to the South Coast Air Quality Management District, with many citing headaches, nausea, nosebleeds and difficulty breathing.Later that year, state regulators learned that the landfill’s temperatures had risen above 200 degrees, melting plastic pipes used to collect landfill gases. An air district inspector also witnessed geysers of liquid waste bursting onto the surface and white smoke venting from large cracks spreading across the reaction area.Air sampling found elevated levels of lung-aggravating sulfur pollutants and cancer-causing benzene. Air samples in 2023 detected benzene concentrations more than eight times higher than the state’s short-term health limit at Hasley Canyon Park, which abuts Live Oak Elementary School, alarming local parents.“I personally have transferred my children to different schools further away,” said Jennifer Elkins, a Val Verde resident whose children attended Live Oak. “I spend three hours a day driving my kids to and from school. The commute has been a sacrifice, but it’s also been well worth it, because I know my children are breathing cleaner air, and I have seen their health improve.”The landfill, owned by Texas-based Waste Connections, installed new heat-resistant equipment to extract liquid waste in an attempt to reduce broiling temperatures. It also installed a large covering over the affected area to suppress odors. It permanently closed and ceased accepting waste this year.Still, the reaction area has tripled in size and could consume the entire 160-acre canyon for many more years. During other underground landfill fires, elevated temperatures have persisted for more than a decade.The issue is, once these broiling temperatures start consuming landfill waste, there’s little that landfill operators can do to snuff them out.The fumes from Chiquita Canyon have pushed some longtime residents to consider moving. After more than 25 years in Val Verde, Abigail DeSesa is contemplating starting anew somewhere else.“This is our life’s investment — our forever home that we were building for retirement and on the verge of paying off,” DeSesa said. “And we may have to start over.”“I don’t know that I can outlast it,” DeSesa added.Chiquita Canyon is not alone.Earlier this year, the South Coast air district learned about another fiery chemical reaction brewing inside El Sobrante Landfill in Corona. In August, Waste Management, the landfill’s owner and operator, acknowledged there was a two-acre “area of concern” where landfill staff had observed temperatures climbing above 200 degrees. Riverside County inspectors also found several fires had ignited on the landfill’s surface in recent years, according to public records.Environmental advocates fear that many more landfills may be on the precipice of these largely unmanageable disasters.According to an analysis by California Communities Against Toxics, there are 18 landfills in California that have had prolonged heat signatures detected by NASA’s Fire Information for Resource Management System, an online tool using satellite instruments to detect fires and thermal anomalies.At least 11 of these landfills requested and received permission from either federal or local environmental regulators to continue operating with higher temperatures than currently allowed, according to public records obtained by the environmental organization.These regulatory exemptions are part of the problem, said Jane Williams, the group’s executive director.“We have 11 landfills across California that have been granted waivers by the government to basically ‘hot rod’ the landfill,” Williams said. “We would really like EPA and state agencies to stop granting landfill waivers. It’s a permission slip to speed in a school zone.”Under newly proposed revisions to state rules, operators must be more transparent in disclosing the temperatures in their gas collection systems. If operators detect elevated temperatures, they must take action to minimize the amount of oxygen in the landfill.While these rule changes might be coming too late to fix the issues near Chiquita Canyon, locals hope it will help others who live in the orbit of the nearly 200 other large landfills in California that could be subject to these rules.“While there’s still a fight here to try to address the concerns at Chiquita Canyon Landfill, we know that there’s an opportunity to really prevent this kind of disaster from happening anywhere else in our state,” said Assemblymember Pilar Schiavo.Dangerous leaksMeanwhile, many other landfills are releasing unsafe amounts of methane, an odorless gas produced by bacteria that break down organic waste.These emissions present two critical issues.First, methane is a powerful greenhouse gas — capable of warming the atmosphere 80 times more than the same amount of carbon dioxide over 20 years. Following California’s large dairy and livestock operations, landfills emit the second-most methane statewide.Second, methane is the primary constituent in natural gas. It can ignite or explode at certain concentrations, presenting a serious safety risk in the event of uncontrolled releases. Several times over the last few years, regulators have detected potentially explosive concentrations in the air and shallow soil near several landfills.Under current landfill regulations, operators are required to monitor for excessive methane leaks four times a year. Many operators hire contractors to walk across accessible portions of the landfill with a handheld leak-monitoring device, an approach that some environmental advocates say is unreliable.In addition, some areas of the landfill are not screened for methane leaks if operators consider them to be unsafe to walk across, due to, for example, steep hills or ongoing construction activities.“Landfills have to monitor surface emissions, but they do that in a very inefficient way, using outdated technology,” Magavern said.Starting this past summer, California has partnered with the nonprofit organization Carbon Mapper to use satellites to detect methane leaks, and already has found 17 coming from landfills. In one case, researchers saw a large methane plume appear to emanate from Newby Island Landfill in San José and drift into a nearby residential neighborhood.Although the state has notified these landfill operators, it currently cannot require them to repair leaks detected via satellite. That would change under the proposed amendments to the state’s landfill regulations. Operators would also have to use state-approved technology to routinely scan portions of their landfills they deem inaccessible.The proposed amendments seek to prevent the most common causes of methane emissions. A series of surveys of landfill operators found 43% of leaks in recent years were caused by one or more of a facility’s gas collection wells being offline at the time.The new rules would require that such wells can only be offline for up to five days at a time for repairs. Operators would also be required to install gas collection systems within six months of when garbage is first placed in a new part of a landfill — rather than the 18-month time frame currently allowed.In addition, landfills would be forced to take actions to fix a leak within three days of detection, rather than 10 days. In theory, that should help reduce the risk of leaks from things like cracks in landfill covers (typically a layer of soil or plastic covering) and damaged components of gas collection systems — two other major sources of leaks that landfill operators have reported.The amended landfill rules could collectively cost private companies and local governments $12 million annually.Some say that’s well worth the cost.A contingent of residents who live near Chiquita Canyon Landfill are flying to Sacramento to attend the state Air Resources Board meeting. They are expected to testify on how the fire and landfill emissions have unraveled the fabric of the semi-rural community.Elkins, the Val Verde resident, appreciated the area’s natural beauty — picturesque hillsides, wildlife and opportunities for stargazing without bright city lights. However, now her family hardly spends any time outdoors due to the noxious odors.Some of her neighbors have moved away, but Elkins and many other longtime locals cannot, no matter how they fear for their health and safety. “The homes are not selling,” she said. “Other homes sit vacant, and community members are paying two mortgages just to get away. And for many of us, it would be financial suicide to move away and start over somewhere new.”

New Texas petrochemical facilities are mostly in low income areas, communities of color, study finds

Researchers evaluated the neighborhoods around 89 proposed or expanding petrochemical facilities across the state using a screening tool from the EPA.

Environment Researchers evaluated the neighborhoods around 89 proposed or expanding petrochemical facilities across the state using a screening tool from the EPA. David J. Phillip/APThis aerial photo shows the TPC petrochemical plant near downtown Houston, background, on Tuesday, Aug. 29, 2017. (AP Photo/David J. Phillip)A recent report from Texas Southern University found that new and expanding petrochemical facilities in Texas are overwhelmingly located in low-income neighborhoods and communities of color. Researchers evaluated the neighborhoods around 89 proposed or expanding petrochemical facilities across the state using a screening tool from the Environmental Protection Agency. They looked at air pollution and proximity to other "hazardous facilities" in the areas. Data related to the race, education, income level and languages within the areas was also collected. Sign up for the Hello, Houston! daily newsletter to get local reports like this delivered directly to your inbox. "The communities that are on the fenceline are getting pollution and they also are getting poverty," said Robert Bullard, one of the study's authors. "And also, if you look at the infrastructures within those neighborhoods that have these facilities, they are of poor quality." The report found that 9 in 10 of the facilities are located in counties with "higher demographic vulnerability" – meaning they had more people of color, more low-income residents, or both, compared to the state and national averages. Over half of the new facilities were slated to be built in communities that have a higher proportion of people of color than the national average. Meanwhile, 30% of the facilities were slated to be built in areas with a poverty rate higher than the national average. "Segregation and racial redlining actually segregated pollution, and it segregated people," Bullard said. The analysis also found that the proposed facilities were being built in areas that are already struggling with air pollution. About 1 in 5 of the proposed facilities are located within the top 10% of areas nationwide with the highest amount of particulate matter pollution, and 46% of the new facilities are slated to be built within the top 10% of communities across the country with the highest amount of air toxins. The facilities were concentrated in 9% of Texas counties, with nearly half of them located in Harris County or Jefferson County.

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