Earth Team Editorial Highlights 2021

The Trojan asteroids in Jupiter’s orbit have been preserved unaltered since the early ages of our Solar System. In October 2021, NASA launched its mission, Lucy, to visit and study these asteroids in order to learn more about the original building blocks that formed our planets.

Sediment core analyses and numerical iceberg modeling suggest icebergs from the North American ice sheets were entrained in large glacial meltwater currents and drifted as far south as the Florida Keys several times during the past ~40,000 years.

Racism thrives in geoscience. We present an antiracism plan to support the recruitment, retention and success of Black, Indigenous, and other people of color in geoscience. Our action plan can be adapted by any organization to remove barriers to participation for all marginalized geoscientists.

While some exoplanets that once orbited Polluted white dwarfs are similar to Earth, most appear to have rock types that are exotic to our Solar System. We thus develop a new classification scheme to describe these new and novel lithologies that appear to be dominant among polluted white dwarfs.

This paper presents MOSAIKS, a system for planet-scale prediction of multiple outcomes using satellite imagery and machine learning (SIML). MOSAIKS generalizes across prediction domains and has the potential to enhance accessibility of SIML across research disciplines.

The nature and evolution of Earth’s crust during the Hadean and Eoarchean is largely unknown due to the lack of preserved material from this period. Here, the authors document a period of crustal rejuvenation between 3.2 and 3.0 Ga, coincident with peak mantle potential temperatures that imply greater degrees of mantle melting and injection of hot mafic-ultramafic magmas into older Hadean-to-Eoarchean felsic crust at this time.

The authors here present a deep learning method to determine the source focal mechanism of earthquakes in realtime. They trained their network with approximately 800k synthetic samples and managed to successfully estimate the focal mechanism of four 2019 Ridgecrest earthquakes with magnitudes larger than Mw 5.4.

The unprecedented cost of the 2018 eruption in Hawai’i reflects an intersection of disparate physical and social phenomena: widely spaced, highly destructive eruptions, and atypically high population growth. These were linked and the former indirectly drove the latter with unavoidable consequences.

Thermal conditions and circulation near glacier fronts are important to understand the recent rapid retreat of calving glaciers. New observations from a glacial lake suggesting a feedback mechanism between atmospheric warming, glacier front melting and calving for freshwater-terminating glaciers.

It is widely hypothesised that primeval life utilized small organic molecules as sources of carbon and energy, however, the presence of such primordial ingredients in early Earth habitats has not yet been demonstrated. Here the authors report the existence of indigenous organic molecules and gases in primary fluid inclusions in c. 3.5- billion-year-old rocks from Western Australia.

Here the authors show that 2-aminoethylphosphonate (2AEP) mineralisation is widespread in the global ocean, operating independently of exogenous inorganic phosphate concentration. They propose 2AEP may be a major route for the regeneration of phosphate required to support marine primary production.

N₂ fixation by heterotrophic bacteria has recently been found to take place on sinking marine particles, but an understanding of its regulation and importance is lacking. Here the authors develop a trait-based model for this N₂ fixation, finding that this once overlooked process could have global importance.

The fate of soil carbon is controlled by plant inputs, microbial activity, and the soil matrix. Here the authors extend the notion of plant-derived particulate organic matter, from an easily available and labile carbon substrate, to a functional component at which persistence of soil carbon is determined.

Up to 40% of the ocean’s fixed nitrogen is lost in oxygen minimum zones (OMZs) by anammox, but despite the importance of this process, nitrogen loss patterns in OMZs are difficult to predict. Here the authors show that ammonium release from small particles is a major control of anammox in the Peruvian OMZ.

The conditions that shaped Earth’s evolution during the Archaean and Proterozoic Eons remain unknown. Using Lake Towuti in Indonesia as an analog of early oceans the authors find that microbial methanogenesis exerts a strong influence with important implications for the composition of Earth’s early atmosphere.

The Paleocene–Eocene boundary coincided with runaway global warming possibly analogous to future climate change, but the sources of greenhouse gasses have remained unresolved. Here, the authors reveal volcanism triggered initial warming, and subsequent carbon was released after crossing a tipping point.

Tree rings are a crucial archive for Common Era climate reconstructions, but the degree to which methodological decisions influence outcomes is not well known. Here, the authors show how different approaches taken by 15 different groups influence the ensemble temperature reconstruction from the same data.

Vegetation emits organic vapors which can form aerosols in the atmosphere and influence cloud properties. Here, the authors show observational evidence that warmer temperatures lead to increased emissions of these aerosols in boreal forests which cause surface cooling, demonstrating a negative climate feedback mechanism.

The role of Southern Ocean gateways contributing to the Eocene-Oligocene climate transition is still debated. Here, the authors present high-resolution ocean simulations to show that gateways opening led to a reorganization of ocean circulation, heat transport and Antarctic surface water cooling.

Climate models project an intensification of extreme precipitation under climate change, but this effect is difficult to detect in the observational record. Here, the authors show that a physically interpretable anthropogenic impact on extreme precipitation is detectable in global observational data sets.

The reasons for concern framework are an effective visualisation of climate change related risks. Here, the authors propose a new framework by which different levels of uncertainty can be included into this aggregated assessment in order to ensure a transparent communication of risks.

Air pollution is a cause of disease for millions around the world and now more than ever urgent action is required to tackle the burden of its impacts. Doing so will not only improve both life expectancy and quality of life, but will also lead to a more just and sustainable world.

Established climate mitigation modelling relies on controversial negative emissions and unprecedented technological change, but neglects to consider degrowth scenarios. Here the authors show that degrowth scenarios minimize many key risks for feasibility and sustainability and thus need to be thoroughly assessed.

Climate change negatively impacts the livelihoods of indigenous communities across the world, including those located on the African continent. This Comment reports on how five African indigenous communities have been impacted by climate change and the adopted adaptation mechanisms.

Outdoor air pollution contributes to millions of deaths worldwide yet air pollution has differential exposures across racial/ethnic groups and socioeconomic status. While green infrastructure has the potential to decrease air pollution and provide other benefits to human health, vegetation alone cannot resolve health disparities related to air pollution injustice. We discuss how unequal access to green infrastructure can limit air quality improvements for marginalized communities and provide strategies to move forward.

Whether or not a city achieves absolute sustainability is difficult to assess with existing frameworks. Here the authors, in a review, show that a further integration of consumption-based accounting and benchmarking is necessary to aid the monitoring and assessment of Sustainable Development Goals in cities.

The ocean supports many livelihoods, but this is currently not sustainable with pressures on the climate and ecosystems. Here, in this perspective, the authors outline the barriers and solutions for financing a sustainable ocean economy.

Individual exposure to heat is associated with adverse health and economic outcomes. Here, the authors show that people of color and people living in poverty bear a disproportionate burden of urban heat exposure in almost all major cities in the continental United States.

Integrating river system and economy-wide models in a dynamic, iterative, bidirectional fashion allows assessing some economic impacts of interventions in river systems. Here the authors use this framework to compare water resources management strategies for the Nile in a quest for efficient use of the river’s limited and stressed water resources.

Access to low cost finance is vital for developing economies’ transition to green energy. Here the authors show how modelled decarbonization pathways for developing economies are disproportionately impacted by different weighted average cost of capital (WACC) assumptions.

European Union’s vulnerability to climate change stretches far beyond its borders. Here the authors find that more than 44% of the EU agricultural imports will become highly vulnerable to drought in future because of climate change.

Intergenerational preconditions and historical conferment of opportunity play a role in social mobility. This study considers the geography of relative deprivation to show how different family groups across Great Britain experience different intergenerational outcomes.