Physics and sustainability

Reproducibility is known to be one of the biggest issues facing science today — but what is less discussed is its connection to science’s environmental impact, as experiments that aren’t replicable still consume resources. Joanna Marshall-Cook and Martin Farley describe processes that can both improve sustainability in science and help tackle the reproducibility crisis.

Environmental concerns and rising energy costs are causing leadership of accelerator facilities to consider the impact of the magnets used. How do permanent magnets — which don’t use electricity to operate — stack up?

Making physics environmentally sustainable requires changes at all levels — individual, institutional and systemic — and all physicists have the chance to act, regardless of career stage. What needs to happen, and how can you get involved?

Energy-recovery linacs are far more efficient than traditional linacs because they directly return the energy of an unused particle beam into RF power that can be used for acceleration. This Review surveys the opportunities and challenges for bringing energy-recovery linacs into the mainstream.

Despite decades of ever more urgent warnings, humanity is failing to address the climate crisis. Astronomer and climate activist Bernadette Rodgers argues that climate action, in any number of ways, can get results and is a moral and professional responsibility for scientists at this critical moment in human history.

Labos 1point5 is a nationwide action-research project that so far about half of research units in France have used to assess their carbon footprint. Tamara Ben-Ari describes some of the scientific findings from the resulting dataset and what they show about how to change the scientific system.

Gathering evidence is key to science, so it is not surprising that scientific institutions have started to report their carbon emissions. However, it is critical to go beyond reporting, and act. Even without a perfect evidence base there are actions scientists and institutions can take that will lead to lasting change, argues Astrid Eichhorn, physicist and chair of the ALLEA Working Group on Climate Sustainability in the Academic System.

Denise Völker, Head of Sustainability at DESY, shares how a dedicated sustainability office can lead the way in cutting the environmental impact of a big science facility.

High-school students are all too aware of climate change, but often aren’t taught how their physics lessons can help them understand the problem and its solutions. Melissa Lord shares tips on how to bridge the gap.

Faced with the knowledge that her students would bear the brunt of the climate crisis, theoretical physicist Vandana Singh looked for ways to integrate climate education into her classroom. She advocates for a holistic approach that integrates science, transdisciplinarity, justice and action.

Physics has an undeniable environmental cost, which sits uncomfortably with the climate and sustainability concerns of many physicists. How can you respond?

Owing to the diminishing returns of deep learning and the focus on model accuracy, machine learning for chemistry might become an endeavour exclusive to well-funded institutions and industry. Extending the focus to model efficiency and interpretability will make machine learning for chemistry more inclusive and drive methodological progress.

Reducing resource usage will improve the environmental impact of high-performance computing — but doing so can clash with the science goals of funders. Computational physicist Peter Skands explains how he approached the conflict.

Data analysis relies heavily on computation, and algorithms have grown more demanding in terms of hardware and energy. Monitoring their environmental impacts is and will continue to be an essential part of sustainable research. Here, we provide guidance on how to do so accurately and with limited overheads.

Large-scale projects have become increasingly important in physics. They are also a source of greenhouse gas emissions. Clarisse Aujoux, Odile Blanchard and Kumiko Kotera describe how to use transparent, open data to estimate these emissions — the first step in taking effective action to reduce them.

Travelling by train rather than plane when possible is a key way to reduce the carbon footprint associated with conferences. Here are some things we’ve learned about how it works in practice.

How can physicists reap the benefits of conferences while reducing their environmental impact? New formats, such as online and multisite conferences, may be part of the solution.

Electronic waste, with printed circuit boards (PCBs) at its heart, is the fastest-growing category of hazardous solid waste in the world. New materials, in particular biobased materials, show great promise in solving some of the sustainability and toxicity problems associated with PCBs, although several challenges still prevent their practical application.

More than half the world’s population lives in cities, which are hotter than rural areas. Jan Carmeliet and Dominique Derome explain what physics modelling can show about how cities get hot, and how to cool them.

Keeping track of the rapidly improving solar cell performance is not as easy as it seems. Martin Green describes the Solar Cell Efficiency Tables that have been providing regular updates of the record solar cell performance since the 1990s.

Organic solar cells that are semitransparent in the visible and strongly absorbing in the near-infrared spectral regions present unique opportunities for applications in buildings and agriculture. This Review surveys recent progress in semitransparent organic photovoltaic devices and discusses strategies to optimize their efficiency, visible transparency, lifetime and scalability.

Defects have a key role in determining the functionality of solids and can make them powerful catalysts. This Review examines defect chemistry in metal oxides and discusses the role that charged defects and polarons have in enabling photoelectrochemical reactions.

Halide perovskites exhibit outstanding semiconductor properties and are a key component of a variety of devices, including solar cells and light-emitting diodes. This Review discusses electrical doping strategies for halide perovskites and takes a critical look at the challenges that need to be overcome to control the electronic properties of these semiconducting materials.

Inexpensive air quality monitors may open up pollution monitoring to the wider public. What can the physics of measurement science tell us about how devices need to perform, and how can standardization help?

Ignition of a millimetre-sized pellet containing a mix of deuterium–tritium, published in 2022, puts to rest questions about the capability of lasers to ignite thermonuclear fuel.

Increasing public and private investment, technological breakthroughs, and a growing number of facilities could bring fusion technology to the delivery era by mid-century. Matteo Barbarino argues that global cooperation and effective regulation are vital in accelerating progress.

Substantial progress has been made towards making fusion a source of commercial energy. One challenge is the damage that filamentary plasma eruptions cause to plasma-facing components. This Perspective summarizes what is understood about these eruptions and strategies for controlling them.

Klaus Hasselmann’s viewpoint has had enormous influence in climate science, both in its theoretical and practical aspects. This Perspective provides a review of Hasselmann’s scientific programme and proposes ways forward for advancing our knowledge on the multiscale behaviour of the climate system, and on the relationship between its forced and free variability.

Five researchers discuss how diverse physics ideas can help better understand the part of Earth’s climate system consisting of snow and ice.

Predicting atmospheric ice formation from aerosol particles for cloud and climate modelling remains challenging. This Review summarizes recent fundamental advances on the governing parameters that lead to ice nucleation from liquid droplets and solid substrates, applying experiments and computational theory.

Although the differential equations that describe the physical climate system are deterministic, there are reasons, both theoretical and practical, why computational representations of these equations should be stochastic. This Perspective surveys the benefits of stochastic modelling of weather and climate.

Internal wave-driven mixing influences the physico-chemical properties of the ocean. This Review outlines the generation, propagation and dissipation of internal waves arising from tides, winds and geostrophic currents, and explores their climatic impacts.