In recent decades, wetland reclamation for agricultural cultivation has remained as one solution to meet rising food demand; however, its agricultural benefits and broader sustainability implications are poorly understood. Here we identify wetland-reclaimed croplands (WRC) globally from 2000 to 2022 and assess their crop production performance and flood exposure risk. Results show that nearly half of WRC exhibited lower crop yields than existing croplands, especially when cultivated with upland crops. WRC contributed only 0.1% to total crop production, yet more than half faced severe flood hazards, with an average flood exposure probability 23 times higher than that of all croplands. Globally, 60% of WRC are subject to dual vulnerabilities of limited agricultural gains and high flood exposure, especially in food-importing or low-income countries. These findings reveal the unsustainability of wetland reclamation as an agricultural expansion strategy and underscore the pressing need to reconcile food security with wetland conservation. As food demand increases, global wetlands are being reclaimed as croplands; however, these reclaimed croplands are not only less productive, but also face substantially higher flood exposure. This dual vulnerability highlights the urgency of balancing food security with wetland conservation.
Climate change is one of the greatest challenges to humanity’s future and worsening of extreme weather is at the leading edge of concerns. The most extreme weather events contribute disproportionately to risk amplification because they account for such a large share of total impacts, and can trigger cascading consequences. Yet our ability to pre-empt such events is limited. In this Perspective, we urge more targeted research combining the power of human imagination with improved understanding of what is possible across impact-relevant systems—including in extreme climate states—to help identify, and avoid, catastrophic consequences from climate change. Extreme weather is becoming more common as Earth’s climate changes. This Perspective argues that the most catastrophic extremes, beyond what has been previously recorded, must be considered and prepared for to avoid drastic impacts.
Unconventional oil and gas development (UOGD), the extraction of hydrocarbons from shale and other low-permeability formations through horizontal drilling and hydraulic fracturing, has bolstered the USA’s domestic energy production and economy. These benefits have been accompanied by public concerns about the industry’s impacts on drinking-water resources, the environment and human health. Here we explore the association between observed groundwater chemistry and documented surface spills from UOGD in the northern Appalachian Basin. Using published data from over 16,000 groundwater samples and high-resolution, physically based groundwater flow and transport modelling, we find that areas with high hydrologic vulnerability to surface spills exhibit a threefold increase in the odds of detecting chemical signatures resembling produced water or deep formation brines in domestic well water, even when accounting for other factors that may explain such chemical imprints. Across our study region, we estimate that over 120,000 people served by domestic wells reside in locations where groundwater is vulnerable to contamination from UOGD activities. Horizontal drilling and hydraulic fracturing are a core part of the US domestic energy economy, particularly in the Appalachian region. However, surface spills occurring in areas of high hydrologic vulnerability could pose a risk to the drinking-water sources of more than 120,000 local residents.
The petrochemical industry is responsible for 13% of global industrial and 3.5% of total greenhouse gas emissions, yet a globally consistent facility-level emissions inventory is lacking. Here we present a bottom-up assessment of historical, current and prospective emissions from 37,379 production facilities, covering 81 chemicals and 2,043 manufacturing processes. We estimate that petrochemical production emitted 2.0 ± 0.8 GtCO2e in 2023 and this could increase to 3.0 ± 1.2 GtCO2e by 2050 under a business-as-usual scenario. Emissions are highly concentrated, with 53% of 2023 emissions arising from 10% of facilities. Among primary chemicals, ethylene and ammonia were the largest emitters, at 290 ± 50 and 250 ± 50 MtCO2e, respectively, in 2023. Our scenario analysis indicates that decarbonization efforts should prioritize the highest-emitting facilities through efficiency improvements, alternative fuels and feedstocks, alongside broad demand reduction and power grid decarbonization. The analysis provides insights for industry, researchers and policymakers to target effective decarbonization in the petrochemical sector. The petrochemical sector is a major source of greenhouse gas emissions, yet a consistent facility-level emissions inventory is missing, hindering effective sectoral decarbonization. This study fills the gap through a bottom-up and detailed assessment of 37,379 facilities globally.
Wastewater treatment, especially nitrogen removal, is a major contributor to global energy consumption and greenhouse gas emissions, driving the need for more sustainable nitrogen removal technologies. However, the practical application of anaerobic ammonium oxidation (anammox) systems is limited by persistent nitrate accumulation, as efficient cross-feeding between anammox bacteria and denitrifiers is hindered by metabolite diffusion and retention challenges. Here we present a strategy using 3D-bioprinted engineered living materials (ELMs) with spatial confinement to enhance the spatial proximity between core species and retain the metabolites, thereby promoting multifaceted cross-feeding between anammox bacteria and denitrifiers. A sodium alginate/cellulose bioink was designed to print anammox consortia into a defined microstructure with both biocompatibility and mechanical stability. The high cell density within the ELMs enhanced microbial interactions, and spatial confinement activated synergistic metabolic pathways and facilitated the exchange of extracellular polysaccharides, amino acids and cofactors between key microbial taxa. The ELMs achieved a 71.43% reduction in start-up time and enabled complete nitrogen removal (100%) without external organic carbon supplementation, which was validated with real wastewater. This work provides a viable approach for the rapid establishment and enhanced performance of anammox systems, contributing to sustainable and energy-efficient wastewater treatment. Nitrate accumulation limits the sustainability of anammox-based nitrogen removal in wastewater treatment. This study shows that 3D-bioprinted engineered living materials with spatial confinement enable complete nitrogen removal by enhancing cross-feeding between anammox bacteria and denitrifiers.
