Global nitrous oxide emissions from livestock manure during 1890-2020: An IPCC tier 2 inventory.

Nitrous oxide (N2O) emissions from livestock manure contribute significantly to the growth of atmospheric N2O, a powerful greenhouse gas and dominant ozone-depleting substance. Here, we estimate global N2O emissions from livestock manure during 1890-2020 using the tier 2 approach of the 2019 Refinement to the 2006 IPCC Guidelines. Global N2O emissions from livestock manure increased by ~350% from 451 [368-556] Gg N year-1 in 1890 to 2042 [1677-2514] Gg N year-1 in 2020. These emissions contributed ~30% to the global anthropogenic N2O emissions in the decade 2010-2019. Cattle contributed the most (60%) to the increase, followed by poultry (19%), pigs (15%), and sheep and goats (6%). Regionally, South Asia, Africa, and Latin America dominated the growth in global emissions since the 1990s. Nationally, the largest emissions were found in India (329 Gg N year-1), followed by China (267 Gg N year-1), the United States (163 Gg N year-1), Brazil (129 Gg N year-1) and Pakistan (102 Gg N year-1) in the 2010s. We found a substantial impact of livestock productivity, specifically animal body weight and milk yield, on the emission trends. Furthermore, a large spread existed among different methodologies in estimates of global N2O emission from livestock manure, with our results 20%-25% lower than those based on the 2006 IPCC Guidelines. This study highlights the need for robust time-variant model parameterization and continuous improvement of emissions factors to enhance the precision of emission inventories. Additionally, urgent mitigation is required, as all available inventories indicate a rapid increase in global N2O emissions from livestock manure in recent decades.

Improved scientific knowledge of methanogenesis and methanotrophy needed to slow climate change during the next 30 years.

Owing to the high radiative forcing and short atmospheric residence time of methane, abatement of methane emissions offers a crucial opportunity for effective, rapid slowing of climate change. Here, we report on a colloquium jointly sponsored by the American Society for Microbiology and the American Geophysical Union, where 35 national and international experts from academia, the private sector, and government met to review understanding of the microbial processes of methanogenesis and methanotrophy. The colloquium addressed how advanced knowledge of the microbiology of methane production and consumption could inform waste management, including landfills and composts, and three areas of agricultural management: enteric emissions from ruminant livestock, manure management, and rice cultivation. Support for both basic and applied research in microbiology and its applications is urgently needed to accelerate the realization of the large potential for these near-term solutions to counteract climate change.

The effect of tablet computer-based telemonitoring added to an established telephone disease management program on heart failure hospitalizations: The Specialized Primary and Networked Care in Heart Failure (SPAN-CHF) III Randomized Controlled Trial.

BACKGROUND: Mobile health applications are becoming increasingly common. Prior work has demonstrated reduced heart failure (HF) hospitalizations with HF disease management programs; however, few of these programs have used tablet computer-based technology. METHODS: Participants with a diagnosis of HF and at least 1 high risk feature for hospitalization were randomized to either an established telephone-based disease management program or the same disease management program with the addition of remote monitoring of weight, blood pressure, heart rate and symptoms via a tablet computer for 90 days. The primary endpoint was the number of days hospitalized for HF assessed at 90 days. RESULTS: From August 2014 to April 2019, 212 participants from 3 hospitals in Massachusetts were randomized 3:1 to telemonitoring-based HF disease management (n = 159) or telephone-based HF disease management (n = 53) with 98% of individuals in both study groups completing the 90 days of follow-up. There was no significant difference in the number of days hospitalized for HF between the telemonitoring disease management group (0.88 ± 3.28 days per patient-90 days) and the telephone-based disease management group (1.00 ± 2.97 days per patient-90 days); incidence rate ratio 0.82 (95% confidence interval, 0.43-1.58; P = .442). CONCLUSIONS: The addition of tablet-based telemonitoring to an established HF telephone-based disease management program did not reduce HF hospitalizations; however, study power was limited.

The cross-section of routine practice of echocardiographic diastolic evaluation in atrial fibrillation in a community hospital: A quality improvement project.

BACKGROUND: The echocardiographic assessment of diastolic function in the context of atrial fibrillation (AF) has been controversial and can be challenging and labor-intensive. We aimed to assess the actual practice of diastolic evaluation in AF in our community hospital echocardiography laboratory and to improve clinical performance by a quality improvement project. METHODS: We reviewed 244 echocardiograms in patients with AF at the time of echocardiography from November 2019 to November 2020 (pre-intervention phase). We classified cases into a complete versus incomplete evaluation group according to the completeness of diastolic parameter measurement. After an educational intervention, we reviewed 68 echocardiograms in patients with AF from August 2021 to October 2021 (post-intervention phase). RESULTS: Our results demonstrated an improvement in a complete diastolic assessment from 69% to 91% after intervention (p < .001). In the pre-intervention phase, the four parameters (mitral inflow pulsed wave Doppler image, left atrium volume index, mitral annular tissue Doppler image [TDI], and tricuspid regurgitation Vmax), mitral annular TDI was not acquired in 71 out of 244 cases (29.1%) and those cases were classified as incomplete evaluation group. Interestingly, in the pre-intervention phase, 57 out of 162 cases (35%) with preserved EF (≥50%) received significantly more incomplete diastolic evaluation than 14 out of 82 patients (17%) with reduced EF (<50%) (p = .004). There were no statistically significant differences in age, BMI, the reason for requesting echocardiography, and patient level of care between the complete and incomplete evaluation groups. In the post-intervention phase, completeness of diastolic measurement in AF was significantly improved compared to the pre-intervention phase (29% vs. 9%, p < .001, respectively). CONCLUSION: A quality improvement project effectively improved the clinical performance of diastolic evaluation in AF in our community echocardiography laboratory. After the intervention, we decreased an incomplete evaluation from 30% to 9%. More efforts should be needed to increase awareness and familiarity in evaluating diastolic function in AF.

PDMS Sponges with Embedded Carbon Nanotubes as Piezoresistive Sensors for Human Motion Detection.

Porous piezoresistive sensors offer promising flexible sensing functionality, such as human joint motion detection and gesture identification. Herein, a facile fabrication method is developed using a microwave-based rapid porogen removal technique for the manufacturing of porous nanocomposite sponges consisting of polydimethylsiloxane (PDMS) and well-dispersed carbon nanotubes (CNTs). The porogen amounts and CNT loadings are varied to tailor the porosity and electrical properties of the porous sensors. The sponges are characterized by a scanning electron microscope (SEM) to compare their microstructures, validate the high-quality CNT dispersion, and confirm the successful nanofiller embedding within the elastomeric matrix. Sponges with a 3 wt% CNT loading demonstrate the highest piezoresistive sensitivity. Experimental characterization shows that the sponges with low porosity have long durability and minimal strain rate dependence. Additionally, the developed sponges with 3 wt% CNTs are employed for the human motion detection using piezoresistive method. One experiment includes fingertip compression measurements on a prosthetic hand. Moreover, the sensors are attached to the chest, elbow, and knee of a user to detect breathing, running, walking, joint bending, and throwing motions.

Characterization of Mice Ubiquitously Overexpressing Human 15-Lipoxygenase-1: Effect of Diabetes on Peripheral Neuropathy and Treatment with Menhaden Oil.

To rigorously explore the role of omega-3 polyunsaturated fatty acids (PUFA) in the treatment of diabetic peripheral neuropathy (DPN), we have created a transgenic mouse utilizing a Cre-lox promoter to control overexpression of human 15-lipoxygenase-1 (15-LOX-1). In this study, we sought to determine the effect of treating type 2 diabetic wild-type mice and transgenic mice ubiquitously overexpressing 15-LOX-1 with menhaden oil on endpoints related to DPN. Wild-type and transgenic mice on a C57Bl/6J background were divided into three groups. Two of each of these groups were used to create a high-fat diet/streptozotocin model for type 2 diabetes. The remaining mice were control groups. Four weeks later, one set of diabetic mice from each group was treated with menhaden oil for twelve weeks and then evaluated using DPN-related endpoints. Studies were also performed using dorsal root ganglion neurons isolated from wild-type and transgenic mice. Wild-type and transgenic diabetic mice developed DPN as determined by slowing of nerve conduction velocity, decreased sensory nerve fibers in the skin and cornea, and impairment of thermal and mechanical sensitivity of the hindpaw compared to their respective control mice. Although not significant, there was a trend for the severity of these DPN-related deficits to be less in the diabetic transgenic mice compared to the diabetic wild-type mice. Treating diabetic wild-type and transgenic mice with menhaden oil improved the DPN-related endpoints with a trend for greater improvement or protection by menhaden oil observed in the diabetic transgenic mice. Treating dorsal root ganglion neurons with docosahexanoic acid but not eicosapentaenoic acid significantly increased neurite outgrowth with greater efficacy observed with neurons isolated from transgenic mice. Targeting pathways that will increase the production of the anti-inflammatory metabolites of omega-3 PUFA may be an efficacious approach to developing an effective treatment for DPN.

Global mapping of crop-specific emission factors highlights hotspots of nitrous oxide mitigation.

Mitigating soil nitrous oxide (N2O) emissions is essential for staying below a 2 °C warming threshold. However, accurate assessments of mitigation potential are limited by uncertainty and variability in direct emission factors (EFs). To assess where and why EFs differ, we created high-resolution maps of crop-specific EFs based on 1,507 georeferenced field observations. Here, using a data-driven approach, we show that EFs vary by two orders of magnitude over space. At global and regional scales, such variation is primarily driven by climatic and edaphic factors rather than the well-recognized management practices. Combining spatially explicit EFs with N surplus information, we conclude that global mitigation potential without compromising crop production is 30% (95% confidence interval, 17-53%) of direct soil emissions of N2O, equivalent to the entire direct soil emissions of China and the United States combined. Two-thirds (65%) of the mitigation potential could be achieved on one-fifth of the global harvested area, mainly located in humid subtropical climates and across gleysols and acrisols. These findings highlight the value of a targeted policy approach on global hotspots that could deliver large N2O mitigation as well as environmental and food co-benefits.

Quantification of global and national nitrogen budgets for crop production.

Input-output estimates of nitrogen on cropland are essential for improving nitrogen management and better understanding the global nitrogen cycle. Here, we compare 13 nitrogen budget datasets covering 115 countries and regions over 1961-2015. Although most datasets showed similar spatiotemporal patterns, some annual estimates varied widely among them, resulting in large ranges and uncertainty. In 2010, global medians (in TgN yr-1) and associated minimum-maximum ranges were 73 (64-84) for global harvested crop nitrogen; 161 (139-192) for total nitrogen inputs; 86 (68-97) for nitrogen surplus; and 46% (40-53%) for nitrogen use efficiency. Some of the most uncertain nitrogen budget terms by country showed ranges as large as their medians, revealing areas for improvement. A benchmark nitrogen budget dataset, derived from central tendencies of the original datasets, can be used in model comparisons and inform sustainable nitrogen management in food systems.

The increasing global environmental consequences of a weakening US-China crop trade relationship.

The consideration of tariffs on China's imports of US agricultural products has focused on economic impacts, while the environmental consequences have received less attention. Here we use a global computable general equilibrium model to evaluate long-term crop portfolio changes induced by China's retaliatory agricultural tariffs and thereby assess the environmental stresses imposed by different crop production portfolios based on region-specific and crop-specific databases. We show that China's tariffs cause unintended increases in nitrogen and phosphorus pollution and blue water extraction in the United States as farmers shift from soybeans to more pollution-causing crops. If diverted to Brazil, China's soybean demands would reduce Brazilian stresses of nitrogen pollution and water use through crop portfolio changes, but may add additional pressures on phosphorus pollution and deforestation. On a global scale, trade policies could help to reduce nutrient pollution and water source depletion by promoting crop production where it is most efficient in terms of nutrient and water use.

Different quantification approaches for nitrogen use efficiency lead to divergent estimates with varying advantages.

Nitrogen use efficiency (NUE) is a key indicator with which to study nitrogen cycles and inform nitrogen management. However, different quantification approaches may result in substantially divergent NUE values even for the same production system or for the same experimental plot. Based on our investigation of the differences between and connections among the three principal approaches for NUE quantification, we offer recommendations for choosing the appropriate approach and call for long-term observations to assess the impacts of management practices.

Interaction between magnesium and methylglyoxal in diabetic polyneuropathy and neuronal models.

OBJECTIVE: The lack of effective treatments against diabetic sensorimotor polyneuropathy demands the search for new strategies to combat or prevent the condition. Because reduced magnesium and increased methylglyoxal levels have been implicated in the development of both type 2 diabetes and neuropathic pain, we aimed to assess the putative interplay of both molecules with diabetic sensorimotor polyneuropathy. METHODS: In a cross-sectional study, serum magnesium and plasma methylglyoxal levels were measured in recently diagnosed type 2 diabetes patients with (n = 51) and without (n = 184) diabetic sensorimotor polyneuropathy from the German Diabetes Study baseline cohort. Peripheral nerve function was assessed using nerve conduction velocity and quantitative sensory testing. Human neuroblastoma cells (SH-SY5Y) and mouse dorsal root ganglia cells were used to characterize the neurotoxic effect of methylglyoxal and/or neuroprotective effect of magnesium. RESULTS: Here, we demonstrate that serum magnesium concentration was reduced in recently diagnosed type 2 diabetes patients with diabetic sensorimotor polyneuropathy and inversely associated with plasma methylglyoxal concentration. Magnesium, methylglyoxal, and, importantly, their interaction were strongly interrelated with methylglyoxal-dependent nerve dysfunction and were predictive of changes in nerve function. Magnesium supplementation prevented methylglyoxal neurotoxicity in differentiated SH-SY5Y neuron-like cells due to reduction of intracellular methylglyoxal formation, while supplementation with the divalent cations zinc and manganese had no effect on methylglyoxal neurotoxicity. Furthermore, the downregulation of mitochondrial activity in mouse dorsal root ganglia cells and consequently the enrichment of triosephosphates, the primary source of methylglyoxal, resulted in neurite degeneration, which was completely prevented through magnesium supplementation. CONCLUSIONS: These multifaceted findings reveal a novel putative pathophysiological pathway of hypomagnesemia-induced carbonyl stress leading to neuronal damage and merit further investigations not only for diabetic sensorimotor polyneuropathy but also other neurodegenerative diseases associated with magnesium deficiency and impaired energy metabolism.

COSORE: A community database for continuous soil respiration and other soil-atmosphere greenhouse gas flux data.

Globally, soils store two to three times as much carbon as currently resides in the atmosphere, and it is critical to understand how soil greenhouse gas (GHG) emissions and uptake will respond to ongoing climate change. In particular, the soil-to-atmosphere CO2 flux, commonly though imprecisely termed soil respiration (RS ), is one of the largest carbon fluxes in the Earth system. An increasing number of high-frequency RS measurements (typically, from an automated system with hourly sampling) have been made over the last two decades; an increasing number of methane measurements are being made with such systems as well. Such high frequency data are an invaluable resource for understanding GHG fluxes, but lack a central database or repository. Here we describe the lightweight, open-source COSORE (COntinuous SOil REspiration) database and software, that focuses on automated, continuous and long-term GHG flux datasets, and is intended to serve as a community resource for earth sciences, climate change syntheses and model evaluation. Contributed datasets are mapped to a single, consistent standard, with metadata on contributors, geographic location, measurement conditions and ancillary data. The design emphasizes the importance of reproducibility, scientific transparency and open access to data. While being oriented towards continuously measured RS , the database design accommodates other soil-atmosphere measurements (e.g. ecosystem respiration, chamber-measured net ecosystem exchange, methane fluxes) as well as experimental treatments (heterotrophic only, etc.). We give brief examples of the types of analyses possible using this new community resource and describe its accompanying R software package.

A comprehensive quantification of global nitrous oxide sources and sinks.

Nitrous oxide (N2O), like carbon dioxide, is a long-lived greenhouse gas that accumulates in the atmosphere. Over the past 150 years, increasing atmospheric N2O concentrations have contributed to stratospheric ozone depletion1 and climate change2, with the current rate of increase estimated at 2 per cent per decade. Existing national inventories do not provide a full picture of N2O emissions, owing to their omission of natural sources and limitations in methodology for attributing anthropogenic sources. Here we present a global N2O inventory that incorporates both natural and anthropogenic sources and accounts for the interaction between nitrogen additions and the biochemical processes that control N2O emissions. We use bottom-up (inventory, statistical extrapolation of flux measurements, process-based land and ocean modelling) and top-down (atmospheric inversion) approaches to provide a comprehensive quantification of global N2O sources and sinks resulting from 21 natural and human sectors between 1980 and 2016. Global N2O emissions were 17.0 (minimum-maximum estimates: 12.2-23.5) teragrams of nitrogen per year (bottom-up) and 16.9 (15.9-17.7) teragrams of nitrogen per year (top-down) between 2007 and 2016. Global human-induced emissions, which are dominated by nitrogen additions to croplands, increased by 30% over the past four decades to 7.3 (4.2-11.4) teragrams of nitrogen per year. This increase was mainly responsible for the growth in the atmospheric burden. Our findings point to growing N2O emissions in emerging economies-particularly Brazil, China and India. Analysis of process-based model estimates reveals an emerging N2O-climate feedback resulting from interactions between nitrogen additions and climate change. The recent growth in N2O emissions exceeds some of the highest projected emission scenarios3,4, underscoring the urgency to mitigate N2O emissions.

Progressive Loss of Corneal Nerve Fibers and Sensitivity in Rats Modeling Obesity and Type 2 Diabetes Is Reversible with Omega-3 Fatty Acid Intervention: Supporting Cornea Analyses as a Marker for Peripheral Neuropathy and Treatment.

PURPOSE: To determine whether cornea nerve fiber density and/or corneal function are valid markers for early detection and treatment of peripheral neuropathy in rats modeling prediabetes and type 2 diabetes. METHODS: High-fat feeding combined without or with low-dose streptozotocin was used to create rat models for prediabetes and type 2 diabetes that were longitudinally studied for loss of structure and function of sensory nerves in the cornea and skin as well as nerve conduction velocity and vascular reactivity of epineurial arterioles. There were three time points examined in each of the three conditions with 12 rats per group. The latest time point (24 weeks of high-fat diet with or without 16 weeks of hyperglycemia) was used to examine reversibility of neuro and vascular pathology following 16 weeks of treatment with menhaden oil, a natural source of long-chain omega-3 polyunsaturated fatty acids. The number of rats in the intervention study ranged from 6 to 17. RESULTS: Our longitudinal study demonstrated that vascular and neural dysfunction associated with obesity or type 2 diabetes occur early and are progressive. Decrease in cornea nerve fiber length and function were valid markers of disease in both the pre-diabetic and diabetic rat models and were more sensitive than decrease in intraepidermal nerve fiber density of the skin and thermal nociception of the hindpaw. Late intervention with menhaden oil significantly reversed both vascular and peripheral nerve damage induced by chronic obesity or type 2 diabetes. CONCLUSION: These studies provide support for examination of corneal structure and function as an early marker of peripheral neuropathy in prediabetes and type 2 diabetes. Furthermore, we demonstrate that omega-3 polyunsaturated fatty acids derived from fish oil are an effective treatment for peripheral neuropathy that occurs with chronic obesity or type 2 diabetes.

Effect of mitoquinone (Mito-Q) on neuropathic endpoints in an obese and type 2 diabetic rat model.

This study sought to determine whether the addition of mitoquinone (Mito-Q) in the diet is an effective treatment for peripheral neuropathy in animal models of diet-induced obesity (pre-diabetes) and type 2 diabetes. Unlike other anti-oxidative stress compounds investigated as a treatment for peripheral neuropathy, Mito-Q specifically targets mitochondria. Although mito-Q has been shown to reduce oxidative stress generated by mitochondria there have been no studies performed of the effect of Mito-Q on peripheral neuropathy induced by diet-induced obesity or type 2 diabetes. Diet-induced obese (12 weeks after high fat diet) or type 2 diabetic rats (12 weeks of high fat diet and 4 weeks after the onset of hyperglycemia) were treated via the diet with Mito-Q (0.93 g/kg diet) for 12 weeks. Afterwards, glucose utilization, vascular reactivity of epineurial arterioles to acetylcholine and peripheral neuropathy related endpoints were examined. The addition of Mito-Q to the diets of obese and diabetic rats improved motor and/or sensory nerve conduction velocity, cornea and intraepidermal nerve fibre density, cornea sensitivity and thermal nociception. Surprisingly, treating obese and diabetic rats with Mito-Q did not improve glucose utilization or vascular reactivity by epineurial arterioles to acetylcholine. These studies imply that mitochondrial dysfunction contributes to peripheral neuropathy in animal models of pre-diabetes and late-stage type 2 diabetes. However, improvement in peripheral neuropathy following treatment with Mito-Q was not associated with improvement in glucose utilization or vascular reactivity of epineurial arterioles to acetylcholine.

Simultaneous numerical representation of soil microsite production and consumption of carbon dioxide, methane, and nitrous oxide using probability distribution functions.

Production and consumption of nitrous oxide (N2 O), methane (CH4 ), and carbon dioxide (CO2 ) are affected by complex interactions of temperature, moisture, and substrate supply, which are further complicated by spatial heterogeneity of the soil matrix. This microsite heterogeneity is often invoked to explain non-normal distributions of greenhouse gas (GHG) fluxes, also known as hot spots and hot moments. To advance numerical simulation of these belowground processes, we expanded the Dual Arrhenius and Michaelis-Menten model, to apply it consistently for all three GHGs with respect to the biophysical processes of production, consumption, and diffusion within the soil, including the contrasting effects of oxygen (O2 ) as substrate or inhibitor for each process. High-frequency chamber-based measurements of all three GHGs at the Howland Forest (ME, USA) were used to parameterize the model using a multiple constraint approach. The area under a soil chamber is partitioned according to a bivariate log-normal probability distribution function (PDF) of carbon and water content across a range of microsites, which leads to a PDF of heterotrophic respiration and O2 consumption among microsites. Linking microsite consumption of O2 with a diffusion model generates a broad range of microsite concentrations of O2 , which then determines the PDF of microsites that produce or consume CH4 and N2 O, such that a range of microsites occurs with both positive and negative signs for net CH4 and N2 O flux. Results demonstrate that it is numerically feasible for microsites of N2 O reduction and CH4 oxidation to co-occur under a single chamber, thus explaining occasional measurement of simultaneous uptake of both gases. Simultaneous simulation of all three GHGs in a parsimonious modeling framework is challenging, but it increases confidence that agreement between simulations and measurements is based on skillful numerical representation of processes across a heterogeneous environment.

Effect of Early and Late Interventions with Dietary Oils on Vascular and Neural Complications in a Type 2 Diabetic Rat Model.

AIMS: Determine the effect of dietary oils enriched in different mono- or polyunsaturated fatty acids, i.e., olive oil (18 : 1, oleic acid), safflower oil (18 : 2 n-6, linoleic acid), flaxseed oil (18 : 3 n-3, alpha linolenic acid), evening primrose oil (18 : 3 n-6, gamma linolenic acid), or menhaden oil (20:5/22 : 6 n-3 eicosapentaenoic/docosahexaenoic acids), on vascular and neural complications in high-fat-fed low-dose streptozotocin-treated Sprague-Dawley rats, an animal model for late-stage type 2 diabetes. MATERIALS AND METHODS: Rats were fed a high-fat diet (45% kcal as fat primarily derived from lard) for 8 weeks and then treated with a low dose of streptozotocin (30 mg/kg) in order to induce hyperglycemia. After an additional 8 (early intervention) or 20 (late intervention) weeks, the different groups of rats were fed diets with 1/2 of the kcal of fat derived from lard replaced by the different dietary oils. In addition, a control group fed a standard diet (4.25% kcal as fat) and a diabetic group maintained on the high-fat diet were maintained. The treatment period was approximately 16 weeks. The endpoints evaluated included vascular reactivity of epineurial arterioles, motor and sensory nerve conduction velocity, thermal and corneal sensitivity, and innervation of sensory nerves in the cornea and skin. RESULTS: Our findings show that menhaden and flaxseed oil provided the greatest benefit for correcting peripheral nerve damage caused by diabetes, whereas enriching the high-fat diet with menhaden oil provided the most benefit to acetylcholine-mediated vascular relaxation of epineurial arterioles of the sciatic nerve. Enriching the diets with fatty acids derived from the other oils provided none to partial improvements. CONCLUSIONS: These studies imply that long-chain n-6 and n-3 polyunsaturated fatty acids could be an effective treatment for diabetic peripheral neuropathy with n-3 polyunsaturated fatty acids derived from fish oil being the most effective.

A world of co-benefits: Solving the global nitrogen challenge.

Nitrogen is a critical component of the economy, food security, and planetary health. Many of the world's sustainability targets hinge on global nitrogen solutions, which, in turn, contribute lasting benefits for: (i) world hunger; (ii) soil, air and water quality; (iii) climate change mitigation; and (iv) biodiversity conservation. Balancing the projected rise in agricultural nitrogen demands while achieving these 21st century ideals will require policies to coordinate solutions among technologies, consumer choice, and socioeconomic transformation.

Six years of ecosystem-atmosphere greenhouse gas fluxes measured in a sub-boreal forest.

Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are the greenhouse gases largely responsible for anthropogenic climate change. Natural plant and microbial metabolic processes play a major role in the global atmospheric budget of each. We have been studying ecosystem-atmosphere trace gas exchange at a sub-boreal forest in the northeastern United States for over two decades. Historically our emphasis was on turbulent fluxes of CO2 and water vapor. In 2012 we embarked on an expanded campaign to also measure CH4 and N2O. Here we present continuous tower-based measurements of the ecosystem-atmosphere exchange of CO2 and CH4, recorded over the period 2012-2018 and reported at a 30-minute time step. Additionally, we describe a five-year (2012-2016) dataset of chamber-based measurements of soil fluxes of CO2, CH4, and N2O (2013-2016 only), conducted each year from May to November. These data can be used for process studies, for biogeochemical and land surface model validation and benchmarking, and for regional-to-global upscaling and budgeting analyses.