Theory gaps in Earth Science

Representative open questions

Showing 30 of 49 — one per source paper, highest-quality first.

• G6-1.5K-MCB: Marine Cloud Brightening scenario design for the Geoengineering Model Intercomparison Project (GeoMIP) in CESM2.1, E3SMv2.0, and UKESM1.1 (2026) · doi

  Significant inter-model differences exist in temperature response patterns to SSP2-4.5 and midlatitude MCB across CESM2.1, E3SMv2.0, and UKESM1.1, but the underlying causes of these inter-model differences in MCB climate response sensitivity remain unexplained and require systematic investigation.

• The impact of aerosol-ice nuclei-cloud interactions on a typical spring dust-precipitation event in China (2026) · doi

  While the study demonstrates that considering both CCN and IN effects improves precipitation simulations by approximately 40% compared to CCN-alone schemes, the underlying mechanisms responsible for this improvement remain incompletely characterized. Investigation into the relative contributions and interactions between CCN and IN pathways across different meteorological and aerosol conditions is needed.

• Revisiting the global budget of atmospheric glyoxal: updates on terrestrial and marine precursor emissions, chemistry, and impacts on atmospheric oxidation capacity (2026) · doi

  Atmospheric oxidation chemistry models require updated compact mechanisms for aromatic precursor oxidation pathways that produce glyoxal, with specific focus on benzene, toluene, and xylene degradation under varying NOx regimes to improve predictions of glyoxal concentrations in urban and industrial regions.

• Dynamics of island mass effect – Part 2: Phytoplankton physiological responses (2026) · doi

  The variability in η' decline across the three island mass effect (IME) zones (sharp decline in Samoa versus marginal decreases in Rapa Nui and Society Islands) despite detected upwelling signatures requires investigation of island-specific hydrodynamic and biogeochemical mechanisms controlling nutrient availability and phytoplankton physiological response patterns.

• Unraveling non-monotonic responses of the El Niño–Southern Oscillation to post-2100 global warming (2026) · doi

  The Wyrtki frequency (WF) and Bjerknes stability (BJ) indices are derived from multivariate linear regression of RO model parameters, but the paper does not assess how regression residuals (ξT and ξh) representing non-resolved nonlinear processes vary with global warming level or interact with the non-monotonic ENSO amplitude response mechanisms.

• Marine chemistry special issue: Aerosol chemistry and impacts on the ocean (2010) · doi

  Boyd et al. (2010) identify that dust-mediated phytoplankton blooms are probably rare due to slow iron dissolution timescales, but the specific dissolution kinetics and the quantitative relationship between iron supply modes (mechanisms, rates, timescales) and subsequent biological response thresholds remain incompletely characterized across different oceanographic regions and seasons.

• Earthquake Induced Landslide Identification to Support Landuse Planning in Rapid Growing Settlements Area of Imogiri and Dlingo Sub-District, Yogyakarta (2026) · doi

  The geological heterogeneity analysis contrasts the weak Semilir Formation (high-risk in Wukirsari) with the competent Wonosari Formation (lower vulnerability in Dlingo), but does not quantify how groundwater saturation and pore pressure changes from high-intensity rainfall (eastern sector) interact with formation-specific geotechnical properties to modulate earthquake-induced landslide susceptibility across formation boundaries.

• Atmospheric Simulation Chambers in the ACTRIS Research Infrastructure (2026) · doi

  Chamber studies of biogenic secondary organic aerosol aging via OH radical reactions (Donahue et al., 2012) have been conducted, but the quantitative relationship between aging timescales in laboratory chambers (typically hours) and atmospheric aging pathways involving aerosol-phase reactions and heterogeneous uptake over days-to-weeks remains unconstrained for integration into regional and global chemical transport models.

• Antarctic marine biology (2011) · doi

  The causal link between climate change and the reported decrease in krill biomass concurrent with increased salps remains speculative. Targeted studies are needed to establish the mechanistic pathways connecting oceanographic changes west of the Antarctic Peninsula to krill population dynamics and salp bloom formation.

• Riparian ecosystem condition and impaired floodplain assessment in the Congaree river watershed, South Carolina (2026) · doi

  The RCA–FIS assessment addresses changing climate and land-use pressures affecting floodplain health, but does not incorporate temporal projections of how riparian condition indicators will respond to specific climate change scenarios (temperature increase, precipitation variability) or projected land-use transitions in the Congaree watershed under different future pathways.

• The chemistry of climate change (2012) · doi

  Contrails are noted to have a warming effect where water vapor forcing outweighs albedo cooling, but the paper provides no mechanistic model for how contrail properties (optical depth, lifetime, altitude, ice crystal size) vary with atmospheric conditions or how this translates to climate forcing at different latitudes and times of day.

• Chemistry of the atmosphere (2012) · doi

  Chapman's mechanism predicts ozone concentrations approximately twice higher than observed measurements and places the ozone layer maximum at a higher altitude than measured. The text identifies that additional ozone-destroying mechanisms beyond Equation 4.55 must be operating in the stratosphere, but does not specify quantitative measurements of these alternative destruction pathways or their relative contribution to the ozone budget.

• Collapse of the Atlantic meridional overturning circulation would lead to substantial oceanic carbon release and additional global warming (2026) · doi

  While monsoon rainfall impacts of AMOC collapse are addressed in a multi-model comparison (citation 21), the mechanisms linking Atlantic Meridional Overturning Circulation weakening to oceanic carbon release and subsequent regional precipitation changes remain incompletely characterized. Coupled ocean-atmosphere modeling studies should explicitly isolate the carbon cycle feedbacks that mediate AMOC-monsoon teleconnections.

• A selection-based framework for evaluating transgenerational phenotypic plasticity under environmental change (2026) · doi

  Temperature-dependent dispersal effects on transgenerational phenotypic plasticity and range shifts in ectotherms have not been integrated into adaptive plasticity models. Future work should incorporate dispersal behavior triggered by parental thermal experience with offspring plastic responses to predict population distribution changes under climate warming.

• Climate change-induced agricultural disasters and policy-based agricultural insurance: empirical findings from China (2026) · doi

  The modest adjustment speed coefficient (−0.263) suggests gradual market correction reflecting institutional frictions, but the paper does not specify which institutional barriers (e.g., information asymmetries, premium subsidy delays, claim settlement lags) drive this slow adjustment or propose targeted policy reforms to accelerate the market's response to changing disaster patterns.

• Human-induced intensification of sea surface temperature regime shifts threatens global Large Marine Ecosystems (2026) · doi

  While the paper documents regime shifts in fish recruitment and growth rates across the Northeast Atlantic, Humboldt Current, and Northwestern Pacific, there is no explicit analysis of whether the mechanistic drivers causing SST regime shifts (e.g., Pacific Decadal Oscillation modulation, Atlantic Multidecadal Oscillation intensification) operate identically across different LMEs or whether regional-specific ocean-atmosphere coupling processes require distinct modeling frameworks.

• Cyclic hot solvent injection: An advantageous injection method compared with mixture solvent in the solvent based heavy oil mining process (2026) · doi

  The asphaltene precipitation mechanism during cyclic hot solvent injection (CHSI) is described only at a basic level. The specific relationship between solvent condensation component at the oil-solvent interface and the extent of asphaltene deposition needs quantitative characterization across different reservoir temperatures and solvent compositions to predict permeability reduction in field applications.

• Reassessing Recent Tectonic Activity in Western Svalbard: Fault Kinematics and Crustal Deformation Patterns (2026) · doi

  Sediment flux records from glacial fjords (Isfjorden) and Cenozoic sedimentation patterns along the southwestern Barents Sea shelf provide proxy evidence for crustal uplift and exhumation, but quantitative forward modeling linking fjord sediment accumulation rates to geodetically-measured present-day vertical crustal motion rates remains underdeveloped.

• Shrub Age and Water Dynamics Influence Primary Production, Carbon, and Nitrogen Stocks in a Coastal Environment (2024) · doi

  The study does not quantify how vegetation-microclimate feedbacks specific to woody plant encroachment in the coastal setting alter soil organic carbon accumulation rates or modify the partitioning of water between differently sized shrubs and potential groundwater recharge.

• Assessment and prediction of dust emissions, deposition and radiation forcing in Central Asia (2026) · doi

  Existing radiative transfer models such as SBDART do not fully account for aerosol–cloud interactions, which are particularly important in regions with high dust concentrations; neglecting this process may introduce biases in radiative forcing estimates.

• Further constraining the role of in-atmosphere production on the global HFC-23 budget (2026) · doi

  The importance of understanding the atmospheric fate of HFO species cannot be understated, as their adoption without sufficient consideration of long-term impacts could echo previous unintended consequences from policy changes concerning fluorinated species.

• Global NO 2 changes between 2019 and 2024 as observed by TROPOMI in urban areas and emerging hotspots (2026) · doi

  Atmospheric chemistry influences observed NO2 variability through seasonal differences in photochemical lifetimes, boundary layer mixing, chemical partitioning between NO and NO2, meteorological variability, and contributions from soil NOx and fire emissions, which can all modulate the magnitude and timing of observed NO2 concentrations.

• Tropical stratospheric upwelling as seen in observations of the tape recorder signal (2026) · doi

  A large amount of variability in tropical upwelling cannot be explained by QBO, ENSO, volcanic forcing, and solar cycle signals, with unexplained peaks in late 2000/early 2001 and decreases from mid-2010 to mid-2011.

• Understanding Ice Sheet Instability: A Review of Thermodynamic and Mechanical Drivers Behind Mass Loss (2026) · doi

  The link between Marine Ice Sheet Instability (MISI) hypothesis and purely atmospheric forcing needs further investigation from a continuum mechanics perspective.

• Compositional Acclimation Can Lessen Tropical Forest Change in Response to Increasing Lightning Frequency: Insights From Simulation Modeling (2025) · doi

  Changes in lightning frequency will not happen alone; increases are expected to be accompanied by increases in windthrow and changes in atmospheric CO2, temperature, rainfall, and other factors.

• Quantitative assessment of the most common mycotoxins found in commercial poultry feed (2024) · doi

  Rising temperatures, increased CO2 levels, and extreme weather events (droughts, heavy rains) favor the growth of mycotoxin-producing moulds, and mycotoxin prevalence is shifting geographically, indicating a need for further research on climate-related impacts on mycotoxin contamination.

• Effects of microtopography and moisture on peatland soil temperature regime (a case study of the ridge-hollow complex Mukhrino bog) (2026) · doi

  While the study identifies that southern hollows are 1-2°C warmer than northern hollows, likely due to greater water saturation, the specific mechanisms linking aspect, insolation, and differential warming in hollow complexes warrant further investigation.

• The collapse of environmental predictability erodes reproductive success in a Tropical seabird (2026) · doi

  Limited discussion of mechanistic pathways linking environmental unpredictability to reproductive failure beyond phenological mismatch; alternative mechanisms warrant investigation.

• The response of Middle Jurassic depositional environments to climate change in the Wucaiwan mining area, Junggar Basin, China (2026) · doi

  While the study establishes linkages between regional environmental perturbation and global climate change, the specific mechanisms of how regional terrestrial ecosystems feedback to regulate the global carbon cycle remain incompletely understood and warrant further investigation.

• The variability of Antarctic fast ice extent related to tropical sea surface temperature anomalies (2026) · doi

  The study focused on remote forcing of tropical and subtropical SSTs on Antarctic fast ice but acknowledges that direct oceanic forcing is local and includes both dynamic factors (currents, tidal effects, and swell) and thermodynamic factors (basal melt) that warrant further investigation.