Feed aggregator

Degraded peatlands emit nearly twice as much greenhouse gas as previously thought, study finds

Phys.org: Earth science - Thu, 12/04/2025 - 02:00
For the first time, researchers have produced a detailed, high-resolution map of peatlands in the EU, showing that these areas emit twice as much greenhouse gases than previously thought. The research, led by eco-hydrologist Quint van Giersbergen of Radboud University, has been published in Nature Communications.

Enhanced Scholte-wave characterization of marine sediments through dispersion-spectrum McMC inversion

Geophysical Journal International - Thu, 12/04/2025 - 00:00
SummaryThis study proposes a dispersion-spectrum inversion method for improved estimation of shear-velocity (VS) profiles in marine sediments using underwater multichannel analysis of surface waves (UMASW). The method leverages an efficient forward modeling algorithm combined with a Markov chain Monte Carlo (McMC) global search to address the nonlinearity inherent in the inversion process. Comparisons with field and synthetic data demonstrate that the VS profiles inverted using the full dispersion spectrum (in terms of the frequency-phase velocity spectrum, FVS) exhibit greater stability and reliability than those obtained through traditional fundamental-mode (FM) inversion. Pseudo two-dimensional VS profiles are constructed by interpolating one-dimensional profiles obtained from the FVS-McMC inversion, showing more continuous subsurface interfaces that align with borehole data. Parametric studies further highlight the influence of Poisson’s ratio, water layer thickness, and VS contrast on the dispersion behavior, underscoring the robustness of the proposed approach for offshore site characterization.

Trump Proposes Weakening Fuel Economy Rules for Vehicles

EOS - Wed, 12/03/2025 - 21:09
body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news regarding law and policy changes that impact science and scientists today.

At the White House today, President Donald Trump announced his administration would “reset” vehicle fuel economy standards. Trump said the administration plans to revoke tightened standards, also known as Corporate Average Fuel Economy (CAFE) standards, set by President Joe Biden in 2024.

“We’re bringing back the car industry that was stolen from us.”

“We are officially terminating Joe Biden’s ridiculously burdensome—horrible, actually—CAFE standards that imposed expensive restrictions and all sorts of problems, all sorts of problems, to automakers,” Trump said. “We’re bringing back the car industry that was stolen from us.”

Automobile executives from Ford, General Motors (GM), and Stellantis joined federal officials, including Department of Transportation Secretary Sean Duffy, at the announcement. The administration said, without providing evidence during today’s announcement, that the current CAFE standards have increased vehicle prices and estimated that changing those standards would save American families $109 billion in total.

Vehicle fuel efficiency standards, which set the average gas mileage that vehicles must achieve, have been in place since 1975. The standards were most recently tightened in June 2024 by the Biden administration, and required automakers to ensure vehicles achieved an average fuel efficiency of about 50.4 miles per gallon by model year 2031. The Biden administration estimated that the rule would lower fuel costs by $23 billion and prevent the emission of more than 710 million metric tons of carbon dioxide by 2050. 

Fuel economy standards have significantly reduced greenhouse gas emissions from vehicles, which are one of the largest sources of carbon emissions in the United States. According to one estimate, fuel economy improvements spurred by the standards have avoided 14 billion tons of greenhouse gas emissions since 1975. 

However, Duffy said, the current standards are “completely unattainable” for automakers.

The announcement did not specify the degree to which the administration would lower the standards.

 
Related

Weakening fuel economy rules for vehicles is the latest step in President Trump’s continued efforts to slow the adoption of electric vehicles and boost the fossil fuel industry. 

Trump’s One Big Beautiful Bill, the omnibus spending bill that became law in July, also eliminated fines for automakers that did not comply with fuel economy standards. The Environmental Protection Agency is also expected to weaken limits of greenhouse gas emissions from vehicles by finalizing the repeal of the 2009 Endangerment Finding, which underpins important federal climate regulations, early next year. 

Policy advocates said weakening the standards would slow the transition to electric vehicles and make the U.S. vehicle market less competitive. “While Trump tells G.M., Ford and others that they needn’t make gas-saving cars, China is telling its carmakers to take advantage of the lack of U.S. competition and accelerate their efforts to grab the world’s burgeoning clean car market,” Dan Becker, director of the Safe Climate Transport Campaign at the Center for Biological Diversity, told The New York Times

However, automakers supported the proposal. “As America’s largest auto producer, we appreciate President Trump’s leadership in aligning fuel economy standards with market realities,” Jim Farley, Ford’s CEO, told Fox News.

“Today is a victory of common sense and affordability,” Farley, who attended the announcement, said. 

The Transportation Department will solicit public comments about the rule and is expected to finalize it next year.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Editorial Board

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s):

Correlative isotope excursions driven by transport, not global environmental change

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Connor S. van Wieren, Blake Dyer, Jon M. Husson

A whole-rock geochemistry-based semi-quantitative proxy for magmatic oxygen fugacity

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Ze Liu, Oliver Jagoutz, Hervé Rezeau, Hong-Luo L. Zhang, Benjamin Klein, Zoe Molitor, Xu-Yang Meng, Di-Cheng Zhu

Modeling magma viscosity and ascent dynamics of the 472 CE sub-Plinian eruption of Somma-Vesuvius (Italy)

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Serena Dominijanni, Laura Calabrò, Emily C. Bamber, Gabriele Giuliani, Dmitry Bondar, Pedro Valdivia, Fabio Arzilli, Giuseppe La Spina, Alexander Kurnosov, Alessandro Vona, Alessandro Longo, Danilo Di Genova

Trace element proxies in seamount olivine reveal the ‘missing pyroxenite’ and refertilized peridotite mantle beneath the East Pacific Rise

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Peng Jiang, Michael R. Perfit, Molly K. Anderson, George Kamenov, Andres Trucco

Mechanism of incorporation of fallout <sup>7</sup>Be, <sup>210</sup>Pb and <sup>210</sup>Po in sediment-laden ice from Lake St. Clair, SE Michigan, during snowstorms: Analogy to that in the Arctic Ocean

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Mark Baskaran, Lathan Saperstein, Max Denny

Dynamics and thermal survival of delaminated orogenic lithosphere in deep mantle

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Zhenhui Cao, Huilin Wang, Jiakuan Wan, Chen Yang

The lithosphere - asthenosphere system seen by surface waves: New insights from radial anisotropy

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): S. Durand, E. Debayle, Y. Ricard

Non-equilibrium behavior of trace elements during zircon crystallization from the melt

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Ilya Bindeman, Oleg Melnik

Neon isotopes in individual vesicles of Icelandic basaltic glasses: Insights into the origin of light volatile elements on earth

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Romain Sauvalle, Manuel Moreira, Bruno Scaillet

Significant crustal uplift attributed to contemporary glacier loss over laterally heterogeneous mantle

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Zhengyang Wang, Wei Feng, Zhongshan Jiang, Zhou Wu, Baoming Tian, Haipeng Luo, Min Zhong, Hao Wei

Density and viscosity variations due to plume melting of a bilithologic mantle: Implications for asthenosphere and hotspot swell root dynamics

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Jia Shao, Jason P. Morgan

Contrasting topography of continental large igneous provinces: Crucial role of crustal flow and intrusion dynamics

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Xiaochuan Tian, W. Roger Buck

Temperature insensitive viscous deformation limits megathrust seismogenesis

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Liam Moser, Matěj Peč, Camilla Cattania

Final differentiation of the lunar magma ocean: genesis of KREEP and the limited role of silicate liquid immiscibility

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Weronika Ofierska, Max W. Schmidt, Christian Liebske, Paolo A. Sossi

P and S wave finite-frequency tomography reveals the impact of slab interference on mantle flow beneath the greater Alpine region

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Yuantong Mao, Xiaotian Tang, Liang Zhao, Marco G. Malusà, Stéphane Guillot, Anne Paul, Stefano Solarino, Xiaobing Xu, Coralie Aubert, Elena Eva, Silvia Pondrelli, Simone Salimbeni, Lei Yang

THEORETICAL BOUNDS ON THE ALTIMETRY BIAS DUE TO EARTH’S CURVATURE IN GROUND-BASED GNSS REFLECTOMETRY

Publication date: Available online 27 November 2025

Source: Advances in Space Research

Author(s): Vitor Hugo de Almeida, Felipe Geremia-Nievinski

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer