The Evolution of Global Surface Ammonia Concentrations during 2001-2019: Magnitudes, Patterns, and Drivers.

Ammonia (NH) is the most prevalent alkaline gas in the atmosphere, with its elevated concentrations posing significant adverse impacts on air quality, ecosystems, and human health across diverse spatial and temporal scales. Given the ongoing global change and intensified anthropogenic NH emissions, it is projected that the global surface NH concentration will escalate further. Here, based on ground observations, gridded data of organic and inorganic nitrogen fertilizer applications, meteorological data, and ancillary information, we estimated changes in global monthly surface NH concentration during 2001-2019 at a 0.

Groundwater-derived carbon stimulates headwater stream CO emission potential on the Qinghai-Tibet Plateau.

CO emissions from headwater streams are a crucial component of greenhouse gas flux in inland waters. However, the influence of groundwater, a major contributor to streams in the Asian Water Tower (Qinghai-Tibet Plateau, QTP), on CO levels remains unclear. This study employed stable isotope analysis and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to demonstrate that groundwater-derived dissolved inorganic carbon (DIC) significantly enhanced CO supersaturation in the Shuiluo stream on the QTP.

Warming exacerbates global inequality in forest carbon and nitrogen cycles.

Forests are invaluable natural resources that provide essential services to humanity. However, the effects of global warming on forest carbon and nitrogen cycling remain uncertain. Here we project a decrease in total nitrogen input and accumulation by 7 ± 2 and 28 ± 9 million tonnes (Tg), respectively, and an increase in reactive nitrogen losses to the environment by 9 ± 3 Tg for 2100 due to warming in a fossil-fueled society.

Molecular composition limits the reaction kinetics of riverine dissolved organic matter decomposition.

The bioavailability and degradation of riverine dissolved organic matter (DOM) play crucial roles in greenhouse gas emissions; however, studies on the kinetic decomposition of fluvial DOM remain scarce. In this study, the decomposition kinetics of dissolved organic carbon (DOC) were characterized using the reactivity continuum model through 28-day bio-incubation experiments with water samples from the Yangtze River. The relationship between DOM composition and decomposition kinetics was analyzed using optical and molecular characterization combined with apparent decay coefficients.

Increased nitrous oxide emissions from global lakes and reservoirs since the pre-industrial era.

Lentic systems (lakes and reservoirs) are emission hotpots of nitrous oxide (NO), a potent greenhouse gas; however, this has not been well quantified yet. Here we examine how multiple environmental forcings have affected NO emissions from global lentic systems since the pre-industrial period. Our results show that global lentic systems emitted 64.

Soil legacy nutrients contribute to the decreasing stoichiometric ratio of N and P loading from the Mississippi River Basin.

Human-induced nitrogen-phosphorus (N, P) imbalance in terrestrial ecosystems can lead to disproportionate N and P loading to aquatic ecosystems, subsequently shifting the elemental ratio in estuaries and coastal oceans and impacting both the structure and functioning of aquatic ecosystems. The N:P ratio of nutrient loading to the Gulf of Mexico from the Mississippi River Basin increased before the late 1980s driven by the enhanced usage of N fertilizer over P fertilizer, whereafter the N:P loading ratio started to decrease although the N:P ratio of fertilizer application did not exhibit a similar trend. Here, we hypothesize that different release rates of soil legacy nutrients might contribute to the decreasing N:P loading ratio.