Five-year flask measurements of long-lived trace gases in India

Abstract. With the rapid growth in population and economic development, emissions of greenhouse gases (GHGs) from the Indian subcontinent have sharply increased during recent decades. However, evaluation of regional fluxes of GHGs and characterization of their spatial and temporal variations by atmospheric inversions remain uncertain due to a sparse regional atmospheric observation network. As a result of an Indo-French collaboration, three new atmospheric stations were established in India at Hanle (HLE), Pondicherry (PON) and Port Blair (PBL), with the objective of monitoring the atmospheric concentrations of GHGs and other trace gases. Here we present the results of the measurements of CO2, CH4, N2O, SF6, CO, and H2 from regular flask sampling at these three stations over the period 2007–2011. For each species, annual means, seasonal cycles and gradients between stations were calculated and related to variations in natural GHG fluxes, anthropogenic emissions, and monsoon circulations. Covariances between species at the synoptic scale were analyzed to investigate the likely source(s) of emissions. The flask measurements of various trace gases at the three stations have the potential to constrain the inversions of fluxes over southern and northeastern India. However, this network of ground stations needs further extension to other parts of India to better constrain the GHG budgets at regional and continental scales.

Globally, greenhouse gas (GHG) reduction is a serious concern. To evaluate whether turfs serve as a GHG sink or source, GHG budget assessments for life cycle are required. However, previous studies have only focused on the use of turfs. To bridge these gaps in literature, this study investigated GHG (CO2, N2O, and CH4) emissions from the disposal of grass clippings and soil GHG fluxes in turfs. Additionally, GHG budgets in the turf production phase were assessed. Finally, inclusive GHG budgets from turf production to disposal of grass clippings for four turf uses (soccer stadium, golf course, office, and urban park) were assessed. Grass clippings were disposed in three forms (incineration, leaving as-is, and biochar). We found that GHG emissions from incineration and leaving 1 t-fresh weight (FW) of grass clippings were 0.711 and 0.207 t-CO2e, respectively. Contrastingly, the GHG emissions from the biochar yield from 1 t-FW of grass clippings were −0.200 t-CO2e. Further, annual soil GHG fluxes in newly established Zoysia and Kentucky bluegrass turfs were calculated at 0.067 and 0.040 tCO2e･ha-1･yr-1, respectively. As the turf grass in production fields sequester large amounts of CO2, GHG budgets in turf production phase were estimated at approximately −20 t-CO2e･ha-1･yr-1. Inclusive GHG budget assessment from turf production to disposal of grass clippings showed that turfs only in the urban parks served as a GHG sink and this ability was comparable to CO2 sequestration in forests. To enhance the ability of GHG sinks and to promote changes from a GHG source to GHG sink, our study revealed the importance of reduction of GHG emissions from energy and resource uses (especially fertilizers and gasoline) for turf management.

Globally, agriculture is directly responsible for 14% of annual greenhouse gas(GHG) emissions and induces an additional 17% through land use change, mostlyin developing countries (Vermeulen et al 2012). Agricultural intensification andexpansion in these regions is expected to catalyze the most significant relativeincreases in agricultural GHG emissions over the next decade (Smith et al 2008,Tilman et al 2011). Farms in the developing countries of sub-Saharan Africa andAsia are predominately managed by smallholders, with 80% of land holdingssmaller than ten hectares (FAO 2012). One can therefore posit that smallholderfarming significantly impacts the GHG balance of these regions today and willcontinue to do so in the near future.However, our understanding of the effect smallholder farming has on theEarth’s climate system is remarkably limited. Data quantifying existing andreduced GHG emissions and removals of smallholder production systems areavailable for only a handful of crops, livestock, and agroecosystems (Herrero et al2008, Verchot et al 2008, Palm et al 2010). For example, fewer than fifteenstudies of nitrous oxide emissions from soils have taken place in sub-SaharanAfrica, leaving the rate of emissions virtually undocumented. Due to a scarcity ofdata on GHG sources and sinks, most developing countries currently quantifyagricultural emissions and reductions using IPCC Tier 1 emissions factors.However, current Tier 1 emissions factors are either calibrated to data primarilyderived from developed countries, where agricultural production conditions aredissimilar to that in which the majority of smallholders operate, or from data thatare sparse or of mixed quality in developing countries (IPCC 2006). For the mostpart, there are insufficient emissions data characterizing smallholder agricultureto evaluate the level of accuracy or inaccuracy of current emissions estimates.Consequentially, there is no reliable information on the agricultural GHG budgetsfor developing economies. This dearth of information constrains the capacity totransition to low-carbon agricultural development, opportunities for smallholdersto capitalize on carbon markets, and the negotiating position of developingcountries in global climate policy discourse.Concerns over the poor state of information, in terms of data availability andrepresentation, have fueled appeals for new approaches to quantifying GHGemissions and removals from smallholder agriculture, for both existing conditionsand mitigation interventions (Berry and Ryan 2013, Olander et al 2013).Considering the dependence of quantification approaches on data and the currentdata deficit for smallholder systems, it is clear that in situ measurements must bea core part of initial and future strategies to improve GHG inventories and

National greenhouse gas (GHG) budget, including CO2, CH4 and N2O has increasingly become a topic of concern in international climate governance. China is paying increasing attention to reducing GHG emissions and increasing land sinks to effectively mitigate climate change. Accurate estimates of GHG fluxes are crucial for monitoring progress toward mitigating GHG emissions in China. This study used comprehensive methods, including emission factor methods, process-based models, atmospheric inversions, and data-driven models, to estimate the long-term trends of GHG sources and sinks from all anthropogenic and natural sectors in China's mainland during 2000–2023, and produced an up-to-date China GHG Budget dataset (CNGHG). The total gross emissions of the three GHGs show a 3-fold increase from 5.0 (95% CI: 4.9–5.1) Gt CO2-eq yr−1 (in 2000) to 14.3 (95% CI: 13.8–14.8) Gt CO2-eq yr−1 (in 2023). CO2 emissions represented 81.8% of the GHG emissions in 2023, while 12.7% and 5.5% were for CH4 and N2O, respectively. As the largest CO2 source, the energy sector contributed 87.4% CO2 emissions. In contrast, the agriculture, forestry and other land use sector was the largest sector of CH4 and N2O, representing 50.1% and 66.3% emissions, respectively. Moreover, China's terrestrial ecosystems serve as a net CO2 sink (1.0 Gt CO2 yr−1, 95% CI: 0.2–1.9 Gt CO2 yr−1) during 2012 to 2021, equivalent to an average of 14.3% of fossil CO2 emissions. Our GHG emission estimates showed a general consistency with national GHG inventories, with gridded and sector-specific estimates of GHG fluxes over China, providing the basis for curtailing GHG emissions for each region and sector.

Monitoring of trace and greenhouse gas fluxes is key to understand the interaction between atmosphere, plants, and soil and therefore to improving our understanding of the climate system in general.Complex flux systems, in environments where both biogenic and anthropogenic sources and sinks play a role, require measurement of many different inert and reactive trace gases and greenhouse gases simultaneously to obtain a complete budget.Until recently, however, the monitoring was usually limited to only a few gases per measurement device making the technique complex and expensive but providing only a limited picture. MIRO Analytical has developed a novel multicompound gas analyzer that can monitor up to 10 air pollutants (CO, NO, NO2, O3, SO2 and NH3), greenhouse gases (CO2, N2O, H2O and CH4) and other atmospheric trace gases such as (OCS, HONO, CH2O) simultaneously at ppb level.The eddy covariance (eddy flux) technique is often used to measure fluxes of trace gases but requires a high time resolution. Our compact instrument, combing several mid-infrared lasers (QCLs), offers 10 Hz sampling rate, outstanding precision, selectivity and accuracy and an automatic water vapor correction, which makes it ideal for eddy covariance flux measurements.In our contribution, we will introduce the measurement technique and will demonstrate application examples of this all-in-one atmospheric flux monitor. The system will be compared to alternative devices in parallel measurements and results of long-term observations and shorter campaigns will be presented.

I. BACKGROUND II. CLIMATE CHANGE IMPACTS IN ARIZONA III. EXECUTIVE ORDER 2005-02 AND THE CLIMATE CHANGE ADVISORY GROUP IV. EXECUTIVE ORDER 2006-13 V. ARIZONA'S CLEAN CAR GHG STANDARDS VI. ARIZONA'S RENEWABLE ENERGY STANDARD VII. THE WESTERN CLIMATE INITIATIVE VIII. OTHER REGIONAL EFFORTS A. Arizona-Sonora Climate Change Initiative B. Southwest Climate Change Initiative C. The Climate Registry IX. OTHER ARIZONA EFFORTS A. Executive Order 2005-05 B. Smart Growth & the Growth Scorecard X. CONCLUSION I. BACKGROUND In the absence of meaningful federal action, it has been up to the states to show leadership on this critical issue. And that is exactly what we have done. Governor Janet Napolitano (1) Arizona is one of the newest and fastest growing states in the country. Over the last twenty years, Arizona's population has nearly doubled. (2) During that same time, greenhouse gas (GHG) emissions in Arizona have skyrocketed, due substantially to the state's population growth. An inventory and forecast of Arizona's GHG emissions prepared in 2005 for the Arizona Climate Change Advisory Group (CCAG) at the direction of then-Governor Janet Napolitano found that, between 1990 and 2005, Arizona's net GHG emissions increased by nearly 56 percent, from an estimated 59.3 million metric tons carbon dioxide equivalent (MMtCO2e) to an estimated 92.6 MMtCO2e. (3) Two sectors directly related to Arizona's rapid population growth--transportation and electricity--accounted for nearly 80 percent of Arizona's total GHG emissions in 2005. (4) Both sectors are growing at relatively high rates as Arizona's population grows. Indeed, with Arizona's population expected to continue to grow at a vigorous pace in the decades ahead, (5) the 2005 inventory and forecast projected that Arizona's GHG emissions would increase 148 percent over 1990 levels by 2020 if steps are not taken to reduce the emissions. (6) Because of Arizona's reliance on gasoline-fueled automobiles and demand for electricity produced by coal-fired power plants, Arizona's GHG emissions increased at a rate more than twice the national average during 1990-2005. (7) Further, Arizona's projected 148 percent growth-rate between 1990 and 2020 is more than three times the projected national average over the same period. (8) Arizona's forecasted GHG increase is the highest known projected emissions growth rate in the country. (9) On the other hand, because of Arizona's mild winters and relative absence of manufacturing and heavy industry, the state's per capita GHG emissions (the total level of statewide emissions divided by state population) is significantly less than the national average: 14 MtCO2e versus 22 MtCO2e. (10) Moreover, while the percentage of GHG emissions from electricity production in Arizona is greater than the national average, Arizona gets slightly less electricity from coal and more from low-GHG-emitting sources, such as nuclear power, hydroelectric power and renewable energy (such as solar and biomass). (11) While Arizona's high emissions growth rate presents challenges, it also provides major opportunities. Because nearly 80 percent of Arizona's GHG emissions are directly related to energy and transportation, Arizona can significantly reduce its GHG emissions by focusing on those sectors. Improved energy efficiency, increased use of renewable energy sources, building new infrastructure right, and increased use of cleaner transportation modes, technologies and fuels are key elements in accomplishing these reductions. They are also all essential ingredients of a new, greener economy toward which the state must move in any event. (12) II. CLIMATE CHANGE IMPACTS IN ARIZONA It is critical that Arizona take action to reduce its GHG emissions because the scientific evidence is clear that Arizona and the Southwest will be especially hard-hit by the impacts of climate change in the future. …

Urban air pollution and greenhouse gas (GHG) emissions stem from diverse sources, including transportation, heating, buildings, waste management, industrial and agricultural activities, and natural events like forest fires. Simultaneous monitoring of air pollutants and GHGs with high selectivity and sensitivity is crucial for identifying and evaluating their sources and sinks, as well as understanding their interactions. Accurate measurements across various spatial and temporal scales are essential for modeling and validating emission inventories or satellite observations.Traditionally, solutions for monitoring air pollutants or GHGs with high precision and temporal resolution have been "one-gas-one-instrument," resulting in large, stationary setups with high energy consumption. MIRO Analytical’s compact laser absorption spectrometer that integrates multiple mid-IR lasers enables simultaneous high-precision measurements of greenhouse gases (CO2, N2O, H2O, CH4), pollutants (CO, NO, NO2, O3, SO2, NH3), and trace gases (OCS, HONO, CH2O) within a single instrument. With a time-resolution of up to 10Hz, it is well-suited for detecting the relationships between co-emitted pollutants and GHGs as well as eddy-covariance flux studies.In our presentation, we will showcase examples of our instrument's applications for mobile monitoring of 10 GHGs and air pollutants in urban areas, as well as airborne measurements using airships or planes. Additionally, we will present results from parallel monitoring with our instrument and conventional gas analyzers used for GHG and air pollutant measurements. This demonstrates our instrument's capability to serve as an all-in-one solution, replacing up to seven standard gas analyzers and enabling a wide range of new mobile multi-compound gas monitoring applications, such as in airplanes or cars.

Although trace stratospheric gases such as ozone have been measured in Antarctica from the surface since 1957 and from balloons since 1966 and stratospheric aerosols have been measured routinely by balloon‐borne particle counters since 1972, only recently has any real interest in these measurements developed. This new awareness is directly related to the realization, in 1985, that springtime Antarctic total ozone had declined about 50% since about 1977. Such an unprecedented, unpredicted change understandably created a great deal of interest in past Antarctic ozone‐related measurements. Early theories of this phenomenon included both chemical and dynamical ozone depletion mechanisms. Chemical theories generally utilized stratospheric particles (created in the low‐temperature environment of the Antarctic stratosphere) to enhance chemical conversion of reservoir chlorine compounds to active ozone‐destroying chlorine heterogeneously. Dynamic models utilized particle heating to lift the polar vortex air mass in spring and cause reductions in ozone. Thus these theories generated an interest not only in ozone measurements but also in stratospheric particulates (aerosols) and in measurements of trace gases which could be used as tracers of atmospheric motions, for example, nitrous oxide. In 1986 the first major field studies, in the National Ozone Expedition, were directed at this problem. In the following review of in situ balloon‐borne measurements of aerosols and trace gases the limited amounts of data prior to 1986 are summarized. The new measurements of 1986 have revealed much concerning the nature of the ozone depletion mechanism. While the steady decline in ozone in the 12‐ to 20‐km region in September can probably only be explained by fast chemistry, the phenomenon appears to be shaped spatially and temporally by dynamical phenomena. The next several years will see expanded research in this area, not only in Antarctica but also in other regions in an attempt to detect reductions in ozone which may occur at these locations.

The real emission mitigation by the ecological restoration projects depends upon the integrated effect of all greenhouse gas (GHG) budgets rather than the carbon sequestration alone. However, a comprehensive and robust methodology for estimating the relevant GHG budgets and net mitigation of China's ecological restoration projects is still urgently to await development. Based on the methods from IPCC and statistical data of the management practices under the projects, we constructed a methodology for carbon accounting and determining net mitigation for ecological restoration projects in China (CANM-EP). GHG emissions generated from different processes and practices of the projects were included in the CANM-EP, and by this methodology, carbon sequestration, GHG balance changes induced by ecological response, on-site and off-site GHG emissions could be estimated. Therefore, the CANM-EP provides comprehensive methods to estimate the whole GHG budgets as well as the net mitigation of China's ecological restoration projects.•The CANM-EP provides accounting methods for comprehensive processes and management practices under respective ecological restoration projects in China.•The CANM-EP could simultaneously estimate carbon sequestration and GHG emissions of the projects.•The CANM-EP indicates net carbon sequestration and net contribution of China's ecological restoration projects to climate change mitigation.

Major US electric utility climate pledges have the potential to collectively reduce power sector emissions by one-third

None of the indicators underlying the 169 targets of the 17 UN Agenda 2030 Sustainable Development Goals (SDGs) allow for the tracking of buildings´ greenhouse gas (GHG) emissions. Due to the continuously decreasing GHG budget and the significant contribution of the building sector to GHG emissions, in this study a new indicator and implementation steps for its practical application are proposed. By the application of the indicator GHG emissions have to be determined once during the building submission procedure and ultimately after completion of the building to obtain a usage permit. Finally, the results must be available to the statistical offices. A simplified Life Cycle Assessment (LCA) is used to calculate the GHG emissions of buildings. The GHG emission benchmark values for comparison are derived by carbon budget approaches. The study presents the theoretical process for the implementation of the proposed indicator in the course of the building submission and introduces the necessary methods. In addition, the decision scenarios after the submission are highlighted as well as a step-by-step time frame for the practical implementation of the indicator and the necessary implementation measures are presented. The developed indicator and the proposed tracking strategy help to address the current lack of effective monitoring mechanisms for GHG emissions from buildings and further improve the emissions database in the buildings sector. Given the importance of the building sector as a significant contributor to GHG emissions and the continuous decrease in global GHG budgets, it is crucial to establish effective tools to measure and monitor these emissions.

We present a 16-month record of ozone (O3), carbon monoxide (CO), total reactive nitrogen (NO y ), sulphur dioxide (SO2), methane (CH4), C2 – C8 non-methane hydrocarbons (NMHCs), C1 – C2 halocarbons, and dimethyl sulfide (DMS) measured at a southern China coastal site. The study aimed to establish/update seasonal profiles of chemically active trace gases and pollution tracers in subtropical Asia and to characterize the composition of the `background' atmosphere over the South China Sea (SCS) and of pollution outflow from the industrialized Pearl River Delta (PRD) region and southern China. Most of the measured trace gases of anthropogenic origin exhibited a winter maximum and a summer minimum, while O3 showed a maximum in autumn which is in contrast to the seasonal behavior of O3 in rural eastern China and in many mid-latitude remote locations in the western Pacific. The data were segregated into two groups representing the SCS background air and the outflow of regional continental pollution (PRD plus southern China), based on CO mixing ratios and meteorological conditions. NMHCs and halocarbon data were further analyzed to examine the relationships between their variability and atmospheric lifetime and to elucidate the extent of atmospheric processing in the sampled air parcels. The trace gas variability (S) versus lifetime (τ) relationship, defined by the power law, S lnx = Aτ− b, (where X is the trace gas mixing ratio) gives a fit parameter A of 1.39 and exponent b of 0.42 for SCS air, and A of 2.86 and b of 0.31 for the regional continental air masses. An examination of ln[n-butane]/ln[ethane] versus ln[propane]/ln[ethane] indicates that their relative abundance was dominated by mixing as opposed to photochemistry in both SCS and regional outflow air masses. The very low ratios of ethyne/CO, propane/ethane and toluene/benzene suggest that the SCS air mass has undergone intense atmospheric processing since these gases were released into the atmosphere. Compared to the results from other polluted rural sites and from urban areas, the large values of these species in the outflow of PRD/southern China suggest source(s) emitting higher levels of ethyne, benzene, and toluene, relative to light alkanes. These chemical characteristics could be unique indicators of anthropogenic emissions from southern China.

Due to its urgency, curbing greenhouse gas (GHG) emissions as fast as possible is pivotal for all countries. Mitigation measures are being initiated and a need for monitoring verification and reporting (MVR) of their efficacy arises. Currently existing science based MVR strategies are either too fine scale, e.g. traditional eddy covariance, or very coarse scale, e.g., atmospheric model inversion from high precision continental scale concentration fields. Integral methods to estimate GHG budgets of landscapes and cities are in the state of development. One element of such systems are turbulent flux measurements from tall tower platforms. To be able to document the green transition of Denmark in terms of reducing GHG budgets, we proposed a network of tall tower GHG flux measurements covering representative urban and remote landscapes. In the first step of the project, we designed and built a prototype of such system and applied it in a rural area close to the Danish Capital of Copenhagen. In this presentation, we define criteria for a successful tall tower based GHG flux observation system for MVR of a change in net GHG emissions. We provide a brief overview how we optimized the design to meet these criteria. Finally, we present some key results from the first five months of continuous observation to demonstrate how well we actually met the criteria with our system and conclude on the future prospects of the proposed tall tower GHG observation network. The results include net fluxes of all major long living GHG (CO2, CH4 and N2O) and two indicator gasses, i.e. carbonyl sulfide (COS) and carbon monoxide (CO). These indicator gases were chosen to represent photosynthesis and to estimate fossil CO2 fluxes from combustion processes. Important results are how accurate the data represent the landscape and what the detection limits for flux estimations of the different GHGs are.

Mitigating Curtailment and Carbon Emissions through Load Migration between Data Centers

Energy-related activities are a major contributor of greenhouse gas (GHG) emissions. A growing body of knowledge clearly depicts the links between human activities and climate change. Over the last century the burning of fossil fuels such as coal and oil and other human activities has released carbon dioxide (CO2) emissions and other heat-trapping GHG emissions into the atmosphere and thus increased the concentration of atmospheric CO2 emissions. The main human activities that emit CO2 emissions are (1) the combustion of fossil fuels to generate electricity, accounting for about 37% of total U.S. CO2 emissions and 31% of total U.S. GHG emissions in 2013, (2) the combustion of fossil fuels such as gasoline and diesel to transport people and goods, accounting for about 31% of total U.S. CO2 emissions and 26% of total U.S. GHG emissions in 2013, and (3) industrial processes such as the production and consumption of minerals and chemicals, accounting for about 15% of total U.S. CO2 emissions and 12% of total ...