Climate policies can backfire by eroding “green” values, study finds

Santa Fe Institute

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Green values can be crowded out or cultivated depending on whether policies feel imposed or embraced, but well-designed policies can cultivate green values if they appear effective and non-intrusive. (image: Irene Pérez)

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Credit: Irene Pérez

A popular vision of life after climate action looks like vegetarians riding bikes, city centers without cars, and people foregoing air travel. But a paper published in Nature Sustainability finds that climate policies targeting lifestyle changes (say, urban car bans) actually may weaken people’s green values, thereby undermining support for other needed environmental policies.

“Policies don’t just spur a target behavior. We find that they can change people’s underlying values: leading to unintended negative effects, but also possibly cultivating green values,” says SFI Complexity Postdoctoral Fellow Katrin Schmelz, lead author on the study. 

Schmelz, a behavioral economist and psychologist who also holds an Associate Professorship at the Technical University of Denmark, began gathering data while at the University of Konstanz in Germany. Along with SFI Professor and economist Sam Bowles, she surveyed more than 3,000 Germans representative of the country’s demographics, asking about climate policies and, for comparison, COVID-19 policies.

The survey yielded evidence that well-intended, but poorly designed, mandates can make even “green” citizens less green. Restrictions that promote carbon-neutral behavior, like urban car bans, may trigger strong negative reactions — even among people who would voluntarily choose sustainable lifestyles.

This erosion of existing values is a clear example of what’s known in psychology and economics as the “crowding-out effect." A person’s aversion to control “crowds out” their pre-existing motivation to follow a green lifestyle — for example, riding their bike, walking, and taking public transportation, or being more mindful when heating or cooling their home. “These crowding-out effects are big enough that policymakers should worry,” says Bowles.

Another key finding, which surprised the authors, was a 52% greater negative response to climate mandates than to COVID-19 mandates. “We saw incredible hostility in the U.S. and other countries towards controls during the COVID-19 pandemic, hindering the implementation of much-needed public policies. It looks like the climate case could be much worse,” says Bowles. “The science and technology to provide a low-carbon way of life is nearly solved. What’s lagging behind is a social–behavioral science of effective and politically viable climate policies.”

The research Schmelz and Bowles have begun is already seeing applications. Last April, policy experts and researchers from various disciplines met at SFI to discuss preliminary findings from the study and brainstorm how to design policy that can encourage green values.

There is reason for optimism, the study shows. Mandate resistance was less for people who felt that policies were effective, didn’t restrict their freedom of choice, and were not intrusive on their privacy or their body. 

“We found three conditions that minimize opposition to mandates, and may even cultivate, rather than crowd out, green values,” says Schmelz. “People are more open to policies that they think are effective (in reducing CO2 emissions), and that they don’t perceive as privacy-intrusive. People also respond much more positively if they don’t feel that a policy restricts their freedom — so in Germany, there is less opposition to limitations on short-haul flights compared to other policies, and this may be because the European train network provides an adequate alternative (which may not be the case in the U.S., for example).”

Read the full paper "An empirically based dynamic approach to sustainable climate policy design" in Nature Sustainability (December 30) DOI: 10.1038/s41893-025-01715-5

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Journal

Nature Sustainability

DOI

10.1038/s41893-025-01715-5 

Article Title

An empirically based dynamic approach to sustainable climate policy design

Article Publication Date

30-Dec-2025

 

Too much hydrogen? Scientists reveal how metabolic shifts and viral defense in syngas microbiomes

Chinese Society for Environmental Sciences

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Workflow of syngas biomethanation under increasing hydrogen ratios. This schematic illustrates the experimental workflow used to evaluate how hydrogen enrichment affects syngas-converting microbiomes. Cultures were initially supplied with baseline syngas (69% H₂, 16% CO₂, 15% CO), followed by stepwise hydrogen increases to 77% and 84%. Samples collected across stages were analyzed using metagenomics, metatranscriptomics, and virome profiling to track changes in microbial composition, viral populations, and metabolic pathways. The approach enabled quantitative comparison of community abundance and activity, revealing metabolic reprogramming and defense activation under hydrogen-rich conditions.

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Credit: Environmental Science and Ecotechnology

Syngas biomethanation—converting CO/CO₂/H₂ into renewable methane—relies on coordinated microbial interactions. This study reveals that excess hydrogen disrupts this balance, reducing methanogenesis efficiency and triggering major shifts in microbial metabolism and viral dynamics. Under hydrogen-rich conditions, the key methanogen Methanothermobacter thermautotrophicus downregulates methane-producing pathways while activating defense systems such as CRISPR-Cas and restriction-modification mechanisms. Meanwhile, acetogenic bacteria intensify carbon fixation through the Wood–Ljungdahl pathway, acting as alternative electron sinks. The findings uncover a previously unclear mechanism of thermodynamic stress and microbiome-virus interplay, offering guidance for optimizing microbial consortia in syngas-to-methane conversion. 

Biomethanation provides an energy-efficient, low-carbon alternative to thermochemical gas conversion, turning biomass-derived syngas into biomethane for circular energy systems. The performance of this process depends on balanced microbial metabolism, where hydrogenotrophic methanogens reduce CO₂ using H₂, supported by acetogens and syntrophic partners. However, syngas composition fluctuates during industrial operation, and the metabolic response to hydrogen excess is poorly understood. Traditional studies observed performance drops at high H₂ supply, but lacked molecular-level mechanistic explanation regarding microbial regulation and viral interactions. Due to these uncertainties, deeper investigation into microbial and viral responses under hydrogen-rich conditions is needed.

Researchers from the University of Padua reported on a 2025 early-access study (DOI: 10.1016/j.ese.2025.100637) in Environmental Science and Ecotechnology demonstrating how hydrogen surplus alters microbiome metabolism and triggers viral defense responses in syngas-converting systems. Using genome-resolved metagenomics, metatranscriptomics and virome profiling, the team monitored microbiomes as syngas composition shifted from optimal ratios to hydrogen-rich conditions. Their findings uncover a stress-driven metabolic reorganization and highlight phage dynamics as a significant ecological dimension in biomethanation efficiency.

The study cultivated thermophilic anaerobic microbiomes under three syngas compositions and applied multi-omics analysis to track responses before and after hydrogen increase. Under near-optimal gas ratios, methane yield improved and the dominant methanogen Methanothermobacter thermautotrophicus maintained stable gene expression. However, when hydrogen supply exceeded stoichiometric demand, methane production declined and transcriptome analysis revealed strong metabolic repression. Key methanogenesis genes—including mcr, hdr, mvh, and enzymes in CO₂-to-CH₄ reduction—were significantly downregulated.

Simultaneously, M. thermautotrophicus activated antiviral defense systems, upregulating CRISPR-Cas, restriction-modification genes, and stress markers such as ftsZ. Virome mapping identified 190 viral species, including phages linked to major methanogens and acetogens. Some viruses showed reduced activity, suggesting defense-driven suppression, while others exhibited active replication patterns. In contrast, several acetogenic taxa—including Tepidanaerobacteraceae—enhanced expression of Wood–Ljungdahl pathway genes (cdh, acs, cooF, cooS) to boost CO/CO₂ fixation and act as electron sinks. This reprogramming indicates a shift from methanogenesis to carbon-fixation-dominant metabolism when hydrogen is excessive.

The authors emphasize that hydrogen excess creates a regulatory bottleneck, pushing methanogens into stress mode while enabling acetogens to take over carbon metabolism. They note that viral interactions—previously overlooked in biomethanation—play a major role in shaping community stability. The team points out that CRISPR-Cas activation and phage suppression indicate a defensive state, suggesting that virome dynamics must be considered in bioreactor design.

This research provides molecular-level evidence that hydrogen oversupply can destabilize methane production, highlighting the need for gas-ratio control in industrial reactors. Understanding how microbial populations reprogram under stress can guide engineering of more resilient biomethanation systems, enabling consistent biomethane yields even with variable feedstocks. The insights into phage-microbe interactions further suggest potential for virome-aware reactor management strategies, including microbial community design, phage monitoring, or antiviral interventions. These findings support future development of carbon-neutral gas-to-energy technologies and scalable waste-to-resource platforms.

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References

DOI

10.1016/j.ese.2025.100637

Original Source URL

https://doi.org/10.1016/j.ese.2025.100637

Funding information

This work was supported by the LIFE20 CCM/GR/001642 – LIFE CO2toCH4 of the European Union LIFE + program and the European Union’s Horizon 2020 research and innovation program under grant agreement No 101084405 (CRONUS).

About Environmental Science and Ecotechnology

Environmental Science and Ecotechnology (ISSN 2666-4984) is an international, peer-reviewed, and open-access journal published by Elsevier. The journal publishes significant views and research across the full spectrum of ecology and environmental sciences, such as climate change, sustainability, biodiversity conservation, environment & health, green catalysis/processing for pollution control, and AI-driven environmental engineering. The latest impact factor of ESE is 14.3, according to the Journal Citation ReportsTM 2024.

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Journal

Environmental Science and Ecotechnology

DOI

10.1016/j.ese.2025.100637 

Subject of Research

Not applicable

Article Title

Hydrogen excess drives metabolic reprogramming and viral dynamics in syngas-converting microbiomes

 

Estimating unemployment rates with social media data

PNAS Nexus

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Social media posts about unemployment can predict official jobless claims up to two weeks before government data is released, according to a study. Unemployment can be tough, and people often post about it online. Sam Fraiberger and colleagues developed an artificial intelligence model that identifies unemployment disclosures on social media. Data from 31.5 million Twitter users posting between 2020 and 2022 was used to train a transformer-based classifier called JoblessBERT to detect unemployment-related posts, even those that featured slang or misspellings, such as “I needa job!”. The authors used demographic adjustments to account for Twitter's non-representative user base, then forecast US unemployment insurance claims at national, state, and city levels. The model captured nearly three times more unemployment disclosures than previous rule-based approaches while maintaining high precision. The method also reduced forecasting errors by 54.3% compared to industry consensus forecasts. The approach proved particularly valuable during the COVID-19 pandemic, when it detected the massive surge in unemployment claims in March 2020 days before official statistics were released. According to the authors, the methodology demonstrates how AI models combined with social media data can complement traditional economic statistics and provide real-time insights for policymaking, especially during economic crises.

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Journal

PNAS Nexus

Article Title

Can social media reliably estimate unemployment?

Article Publication Date

30-Dec-2025

 

Examining private equity’s role in fertility care

Researchers find over 50% of IVF cycles are now done at fertility clinics affiliated with private equity firms

Michigan Medicine - University of Michigan

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The rise of private equity firms investing in health care facilities across the United States has been exploding in the last decade.

Because of that rapid growth, researchers have been digging into what this could mean for health care and patients in the long term.

In recent years, private equity firms have become more active in the fertility space, where many patients seek care for reproductive issues and pursue in vitro fertilization, or IVF, which costs thousands of dollars, and usually isn’t covered by insurance.

James Dupree, M.D., M.P.H., and his colleagues wanted to explore what these changes could mean for patients with infertility.  Dupree is a professor of urology and obstetrics and gynecology at the University of Michigan Medical School, who directs U-M Health’s Male Fertility Preservation Program and studies fertility care.

In their new paper published in JAMA, the team shows that since 2013, expansive growth has been seen in affiliations between fertility clinics and private equity firms.

They also find that over half of IVF cycles in the country in 2023 were done at clinics affiliated with private equity firms.

More about the paper

A federal law requires every fertility clinic to report data about their IVF cycles to the federal Centers for Disease Control and Prevention.

The team used those reports from 2013 to 2022 to examine every IVF clinic in the country, which includes private practices and hospital-based clinics.

They used other databases and online searches to identify which clinics were affiliated with private equity firms.

What they found was pretty dramatic growth. In 2013, only 4% of fertility clinics were affiliated with private equity firms. But since then, the number has exploded.

“As of 2023, we estimate that 32% of IVF clinics were affiliated with private equity firms,” explained Dupree. “And these clinics affiliated with these private equity firms are performing over half of the IVF cycles in the country.”

So what does that mean?

“There’s a lot we don’t know yet. It might be good for patients; it costs a lot of money to modernize IVF laboratory equipment and perform outreach to patients and private equity firms can provide capital to hopefully improve quality and patient care.”

He also explains that in other health care settings outside fertility care, there’s data to suggest quality could decline while costs increase.

“We don’t know yet in the fertility world whether this is a net gain for patients or net loss,” he said.

Dupree emphasizes how private equity-supported fertility care will be a crucial business model to continue examining, especially with the government’s recent interest in making IVF care more accessible to Americans with infertility.

He said, “Given how prevalent the business model is, we need to do more research and understand the benefits and risks — like the quality of care, cost of care, access to care — are they better or are they worse?”

As a top researcher in the area, Dupree and his team will continue his work looking into fertility care across the United States, including  how IVF is covered by insurance companies, to help hopefully inform future health policies and help patients in the long run.

The study’s first author, Jesper Ke, M.D., MBA, is a resident physician at the Yale School of Medicine, and graduated from the U-M Medical School and Ross School of Business in 2025. Other authors are U-M medical student Joshua Chen, U-M statistician Elena Chun, M.S., and U-M urology professor Vahakn Shahinian, M.D.

Dupree and Shaninian are members of the U-M Institute for Healthcare Policy and Innovation, which sponsored the research through a grant from its Policy Sprints program.

Paper cited: “Trends in Private Equity Affiliations with Fertility Clinics in the US,” JAMA, doi:10.1001/jama.2025.24516

Written by Johanna Younghans Baker

 

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Journal

JAMA

DOI

10.1001/jama.2025.24516 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Trends in Private Equity Affiliations with Fertility Clinics in the US

Article Publication Date

30-Dec-2025