Desert Soils Emit Potent Greenhouse Gases Through Chemical Reactions Immediately After Wetting, New Research Finds
In a compelling new study that shatters previous paradigms, scientists at Ben-Gurion University of the Negev have uncovered that desert soils can release significant amounts of potent greenhouse gases within minutes of exposure to moisture, even when devoid of live microbial communities. This revelation, published by Dr. Isaac Yagle and Prof. Ilya Gelfand in Scientific Reports, challenges the entrenched belief that microbial activity is solely responsible for the sudden bursts of gases such as nitrous oxide (N₂O) and nitric oxide (NO), commonly witnessed after dry spells in arid regions.
Historically, pulse emissions of greenhouse gases following rainfall events in drylands have been attributed almost exclusively to microbial respiration and metabolism. Semiarid soils, upon rewetting, activate dormant microbial populations which rapidly metabolize available organic substrates, resulting in elevated carbon dioxide (CO₂) and reactive nitrogen species emissions. However, the new experimental evidence suggests that abiotic, or non-biological, processes play a far more crucial role than previously appreciated, particularly for nitrogenous gases.
The research team designed meticulous laboratory experiments using samples of desert soil collected near the Dead Sea, a region emblematic of extreme aridity and unique geochemical conditions. They subjected the soils to sterilization via high-dose gamma irradiation, a technique effective at eradicating virtually all living microorganisms without altering the chemical and physical nature of the soil matrix. This approach allowed the researchers to isolate non-biological gas emission mechanisms.
Remarkably, upon rewetting the sterilized soils, the team observed immediate and substantial emissions of N₂O and NO—up to 13 times more NO and five times more N₂O than the unsterilized, live soils emitted under identical conditions. This startling discovery underscores the significance of chemical reactions independent of microbial mediation. It highlights the presence of intrinsic soil processes capable of rapidly transforming nitrogen compounds into these climate-active gases.
According to Dr. Yagle, the dominant post-wetting emissions of nitrogen oxides stem from abiotic chemical pathways. These may involve redox reactions between soil minerals, nitrogen-containing compounds, and water molecules, facilitated by factors such as pH changes, oxygen availability, and soil mineralogy. The findings imply that standard biogeochemical models, which often conflate greenhouse gas fluxes with microbial activity, may substantially underestimate the contributions from chemistry-driven sources in dryland environments.
While carbon dioxide fluxes did remain higher in live soils—consistent with microbial respiration—the study revealed a notable share of CO₂ evolved from non-biological origins. This portion arises from physical processes such as the dissolution and acid-driven decomposition of soil carbonate minerals, releasing CO₂ upon wetting, and from the rapid release of trapped soil gases. These abiotic contributions to CO₂ emissions complicate the previously binary notion that soil respiration is exclusively biological.
The implications of this work are particularly urgent given global climatic trends. Dryland regions, which already constitute over 40% of Earth’s land surface, are expected to expand further due to anthropogenic warming, transforming global biogeochemical cycles. Coupled with the increasing irregularity of precipitation patterns, this expansion could intensify the frequency and magnitude of abiotic greenhouse gas emissions, accelerating climate feedback loops.
Prof. Gelfand emphasizes that overlooking abiotic emissions risks critical underestimation of regional and worldwide greenhouse gas budgets. Current climate projections and mitigation strategies must therefore incorporate these newly recognized chemical pathways to accurately predict future atmospheric composition and inform environmental policy.
The study also opens new avenues for soil science, urging deeper investigation into the responsible mineralogical and chemical mechanisms. Understanding the specific soil constituents and environmental conditions that facilitate such chemical gas production could lead to improved soil management practices aimed at mitigating undesired greenhouse gas outputs.
This research was generously funded by the Israel Science Foundation and the Ministry of Science, Technology and Space of Israel, reflecting the strategic importance placed on comprehending dryland emissions in the face of global climate change.
As novel findings continue to reshape our understanding of Earth’s carbon and nitrogen cycles, this work represents a critical leap forward. Inserted into the broader conversation on climate science, it challenges the scientific community to revisit assumptions and refine models to account for non-biological processes that play stealthy but powerful roles in shaping atmospheric chemistry.
Subject of Research: Not applicable
Article Title: Abiotic reactions drive post-wetting soil emissions of N2O and NO and contribute partially to CO2 emissions
News Publication Date: September 3, 2025
Web References: DOI:10.1038/s41598-025-12362-3
Keywords: Climatology; Climate change effects; Environmental issues; Greenhouse effect; Soil chemistry; Soil respiration; Soils
