Paleoclimatologists have long recognized that H and O isotopes of materials in lake sediments can help reconstruct past climate and environmental change. Here, a global synthesis of O isotopes in lab-cultured or core-top carbonates and organic macrofossils and of H isotopes in core-top sedimentary plant waxes confirms their strong correlations with source water isotopes. New proxies, such as H isotopes of microbial lipids, are also emerging. Given the prevalence of lakes around the world, these methods show immense promise for generating networks of water-isotope reconstructions needed to characterize past climates. This review summarizes current knowledge of these proxies, their relationships to modern water isotopes, and challenges in their interpretation. Future progress in applying water-isotope proxies would benefit from collecting relevant site environmental and ecological data, generating calibrated water-isotope reconstructions for direct comparison with observational data, and cross-validating reconstructions across multiple proxies or sites. ▪ Reconstructions of past water isotopes promise rich insight into paleoclimate dynamics and have support from a range of modern calibration studies. ▪ Multiple water-isotope proxies, including carbonate minerals, aquatic organism remains, and leaf waxes, reliably track meteoric water isotopes. ▪ Newly emerging water-isotope proxies, such as archaeal and bacterial glycerol dialkyl glycerol tetraethers, promise to expand the range of settings and questions available for investigation. ▪ Expanding modern calibration datasets can clarify the limitations on water-isotope reconstructions while enhancing interpretations.

The Double Asteroid Redirection Test (DART) was NASA's first planetary defense test mission, designed to validate the technologies and methods associated with using a kinetic impactor to deflect asteroids that pose a threat to Earth. On September 26, 2022, DART intentionally collided with Dimorphos, the moonlet of the near-Earth asteroid Didymos. Observations over the following weeks and months confirmed that DART's impact changed Dimorphos's orbit around Didymos, reducing its speed by 2.6 mm $/$ s. In addition, the DART impact provided the opportunity to observe the creation and evolution of the resulting ejecta, to investigate the dynamics within a perturbed binary system, and to study a natural-scale asteroid impact experiment. Additionally, the Didymos-Dimorphos system was the first binary near-Earth asteroid system investigated by spacecraft, and Dimorphos is the smallest asteroid visited by spacecraft to date. We detail the science and planetary defense findings of DART and look to future advancements. ▪ NASA's Double Asteroid Redirection Test (DART) mission was the first to demonstrate asteroid deflection, autonomously navigating to impact the asteroid Dimorphos on September 26, 2022. ▪ DART's successful planetary defense test validated that the kinetic impactor (KI) technique is a viable means to alter an asteroid's future path, which could potentially be used to prevent a future Earth impact. ▪ Analysis of the DART impact event and the resulting aftermath showed that the efficiency of the deflection achieved by the KI technique depended on the asteroid's properties. ▪ Prior information about the asteroid and its properties, such as by a reconnaissance mission, has the potential to allow optimization of the KI technique for asteroid deflection. ▪ Warning time is key for utilizing the KI technique to prevent a potential Earth impact, stressing the need for a planetary defense strategy that includes searching for asteroids and characterizing them in addition to developing mitigation approaches. ▪ In addition to advancing planetary defense objectives, the DART mission provided the first close-up visit to a binary asteroid system and measurements on the smallest asteroid visited by a spacecraft to date. ▪ The success of the DART mission relied on an interdisciplinary and international team, demonstrating the value of wide-ranging cooperation for planetary defense efforts.

Vertical land motion (VLM) is an underrecognized hazard in susceptible coastal cities, especially those experiencing rapid urbanization. Human-induced VLM often causes elevation loss (subsidence) at rates that exceed, sometimes by an order of magnitude or more, those of climate-driven sea-level rise. Local land subsidence (LLS) also damages infrastructure, disrupts drainage, and alters flood dynamics, yet its broader impacts remain poorly quantified and systematically assessed. This review synthesizes the scientific, technical, and policy dimensions of VLM, with particular focus on LLS, highlighting how natural processes and human activities interact to amplify coastal hazards. We examine the geophysical drivers of VLM, advances in monitoring and modeling, and their integration into hazard assessment frameworks. We consider socioeconomic and infrastructural vulnerabilities of city residents, especially where limited observational capacity and governance gaps intensify risk. VLM acts as both a physical amplifier and a socio-institutional blind spot within coastal adaptation planning, requiring real-time data integration, scenario testing, and inclusive policy development. Finally, we identify key research frontiers—including subsidence mitigation strategies, dynamic VLM projections, and equitable, high-resolution risk assessment—to support more resilient, adaptive, and just coastal futures. ▪ Tectonics, sediment compaction, groundwater extraction, and urban loading combine to produce complex, nonlinear patterns of vertical land motion that shape local hazard dynamics. ▪ Local land subsidence, often exceeding the rate of global sea-level rise, is the dominant and least understood driver of coastal flooding and infrastructure risk in many urban regions worldwide. ▪ Subsidence disproportionately affects marginalized communities, exacerbating social inequities, driving displacement, and eroding cultural heritage, underscoring the need for inclusive, justice-centered adaptation frameworks. ▪ Closing critical data and policy gaps through coordinated vertical land motion observation, open-access standards, and equitable governance is essential to safeguard coastal populations and sustain long-term urban resilience.

Volcanic eruptions exert a profound influence on tropical hydroclimate, including interannual variability associated with the El Niño–Southern Oscillation. This review synthesizes recent advances in understanding these impacts through an energy framework that links radiative forcing to shifts in the Intertropical Convergence Zone (ITCZ) and global monsoon systems. While global responses are robust in climate models, regional expressions remain uncertain due to biases and limitations in both simulations and paleoclimate reconstructions. Nonetheless, consistent patterns emerge—such as ITCZ displacement and reduced monsoon precipitation—that align with energetic theory, offering a physically grounded explanation for observed hydroclimatic anomalies following eruptions. This framework also provides a basis for estimating potential hydroclimate impacts of future volcanic events. ▪ Volcanic eruptions strongly influence tropical hydroclimate, but the mechanisms linking radiative forcing to large-scale responses are not fully understood. ▪ We assess evidence from climate models and paleoclimate reconstructions, noting robust global responses but regional differences due to model biases and data limitations. ▪ The energy framework provides a physically based foundation for anticipating tropical hydroclimate responses to future volcanic eruptions. ▪ Consistent patterns emerge such as ITCZ shifts and weakened monsoons, explained by energy theory and underpinned by observed posteruption climate anomalies.

This review examines the societal ramifications of large volcanic eruptions—not the proximal impacts of lava, ash, pumice, and gaseous emissions but rather the consequences of the climate forcing triggered by dispersal of volcanic sulfate aerosol in the stratosphere. Using ice core records of volcanism and tree-ring data of summer temperature anomalies, we analyze 38 preindustrial eruptions that injected an estimated 6 Tg or more of sulfur into the stratosphere. We then explore more than 100 works that consider the volcanism-climate-society nexus, teasing out the key elements of their arguments for or against the role of volcanically forced climate change in far-field societal impacts. As well as summarizing and interrogating the history of ideas and state of the art on this topic, we hope to stimulate further holistic, interdisciplinary approaches to assess the broader implications of volcanic eruptions, particularly for global food security—both in the past and in the future. ▪ There are compelling arguments to consider the role of volcanically forced climate change in explanations of history. ▪ Such research requires integration of geographical, ecological, demographic, econometric, and other data with historical sources and narratives, and therefore demands cross-disciplinary conversation. ▪ Statistical evidence is needed to attribute weather and climate extremes to volcanic forcing, and agricultural and pastoral responses to climate anomalies must be reconstructed at high spatiotemporal resolution. ▪ Several prominent climate forcing eruptions in circa 304, 1182, 1345, and 1453 CE have hitherto received comparatively little attention.

Born on December 12, 1937, I remember the first bombing of Moscow by the Germans in 1941. My schooling began in 1944, and I soon became interested in chemistry, setting up a kind of makeshift chemical laboratory behind a high cupboard in my house. I enrolled in Moscow University in 1955 and published my first scientific paper in 1959. After entering graduate school in 1960, I produced dense silica with a rutile structure, a natural analog of which was later named stishovite. I received my doctorate in 1961 and got a job at the Institute of Crystallography in 1962, where I worked until 1993. My first visit to the West was in 1976. I was became a Fairchild Distinguished Scholar at Caltech in 1989–1990 and a member of the USSR Academy of Sciences in 1990. I was a Miller Professor at the University of California, Berkeley and an Orson Anderson Distinguished Scholar at Los Alamos National Laboratory. From 1993 to 2022, I was director of the Institute for High Pressure Physics. During that time, I was awarded the P. Bridgman Gold Medal and the Gold Medal of P. Kapitsa.

The emergence of continental crust above sea level influences Earth's surface environments and climate patterns, and it creates diverse habitats that promote biodiversity. Earth exhibits bimodal hypsometry with elevated continents and a submerged seafloor. However, it remains elusive when and how this unique feature was first established. The geological record suggests the presence of subaerial landmasses between ca. 3.8 and 2.4 billion years ago (Ga), but their spatial extent and longevity remain unclear. Further, the tectonic processes governing the proportion of continental land to ocean basins and topography during this period are poorly understood. Here, we synthesize a variety of geological and geochemical proxies to suggest that crustal emergence did occur in the early-to-mid Archean, primarily exposing precratonized volcanic crust for brief time periods. Stable continental crust on a regional scale (as cratons) began emerging around ca. 3.2–3.0 Ga, facilitated by the development of thick, stable cratonic lithospheres. Over hundreds of millions of years, voluminous magmatism within a plateau-type setting led to the formation of thick, felsic crust and depleted mantle keels, allowing cratons to rise above sea level via isostatic adjustment. The areal extent of emergent land increased from ca. 3.0 to 2.5 Ga owing to the formation of more cratons, likely coinciding with the onset of plate tectonics, and culminated around ca. 2.5–2.2 Ga when land surface area and freeboard conditions resembled those observed today. These newly emerged landmasses possibly played a critical role in oxygenating the atmosphere and oceans, cooling the climate, and promoting biodiversity during the late Archean to early Paleoproterozoic. ▪ Continental emergence marks a pivotal moment in Earth's history, impacting the planet's atmosphere, oceans, climate, and life evolution. ▪ We review the rock record to infer the timing, nature, and tectonic drivers of continental emergence on early Earth. ▪ Emergence on early Archean Earth was mostly transient, exposing primarily volcanic crust. ▪ The first stable continental land formed at ca. 3.2–3.0 Ga due to the development of thick cratons and their isostatic adjustment. ▪ Emergent land area increased from ca. 3.0 to 2.5 Ga as more felsic crust formed and plate tectonics began.

Emplacement of the Siberian Traps large igneous province (LIP) around 252 Ma coincided with the most profound environmental disruption of the past 500 million years. The enormous volume of the Siberian Traps, its ability to generate greenhouse gases and other volatiles, and a temporal coincidence with extinction all suggest a causal link. Patterns of marine and terrestrial extinction/recovery are consistent with environmental stresses potentially triggered by the Siberian Traps. However, the nature of causal links between the LIP and mass extinction remains enigmatic. Understanding the origins, anatomy, and forcing potential of the Siberian Traps LIP and the spatiotemporal patterns of resulting stresses represents a critical counterpart to high-resolution fossil and proxy records of Permian–Triassic environmental and biotic shifts. This review provides a summary of recent advances and key questions regarding the Siberian Traps in an effort to illuminate what combination of factors made the Siberian Traps a uniquely deadly LIP. ▪ Large igneous provinces such as the Siberian Traps are capable of triggering global environmental destabilization. ▪ Greenhouse gases generated by Siberian Traps magmatism played a major role in driving the climate changes that triggered the end-Permian mass extinction. ▪ The end-Permian extinction fundamentally altered the evolutionary trajectory of Earth's biosphere, creating ecological space for many of the organisms seen today. ▪ Determining the timing and patterns of end-Permian marine and terrestrial mortality and recovery and the timing and character of Siberian Traps magmatism is key in understanding the causal link between magmatism and extinction. ▪ Understanding the cause(s) of past extinction events informs hypotheses about current and future environmental destabilization.

Determining the composition of Earth's lower mantle, which constitutes almost half of its total volume, has been a central goal in the Earth sciences for more than a century given the constraints it places on Earth's origin and evolution. However, whether the major element chemistry of the lower mantle, in the form of, e.g., Mg/Si ratio, is similar to or different from the upper mantle remains debated. Here we use a multidisciplinary approach to address the question of the composition of Earth's lower mantle and, in turn, that of bulk silicate Earth (crust and mantle) by considering the evidence provided by geochemistry, geophysics, mineral physics, and geodynamics. Geochemical and geodynamical evidence largely agrees, indicating a lower-mantle molar Mg/Si of ≥1.12 (≥1.15 for bulk silicate Earth), consistent with the rock record and accumulating evidence for whole-mantle stirring. However, mineral physics–informed profiles of seismic properties, based on a lower mantle made of bridgmanite and ferropericlase, point to Mg/Si ∼ 0.9–1.0 when compared with radial seismic reference models. This highlights the importance of considering the presence of additional minerals (e.g., calcium-perovskite and stishovite) and possibly suggests a lower mantle varying compositionally with depth. In closing, we discuss how we can improve our understanding of lower-mantle and bulk silicate Earth composition, including its impact on the light element budget of the core. ▪The chemical composition of Earth's lower mantle is indispensable for understanding its origin and evolution.▪Earth's lower-mantle composition is reviewed from an integrated mineral physics, geophysical, geochemical, and geodynamical perspective.▪A lower-mantle molar Mg/Si of ≥1.12 is favored but not unique.▪New experiments investigating compositional effects of bridgmanite and ferropericlase elasticity are needed to further our insight.