A quantitative comparison and analysis on the assessment indicators of greenhouse gases emission

Anthropogenic greenhouse gases （GHG） emission and related global warming issues have been the focus of international communities for some time. The international communities have reached a consensus to reduce anthropogenic GHG emissions and restrain global warming. The quantitative assessment of anthropogenic GHG emissions is the scientific basis to find out the status of global GHG emission, identify the commitments of each country, and arrange the international efforts of GHG emission reduction. Currently the main assessment indicators for GHG emission include national indicator, per capita indicator, per GDP indicator, and international trade indicator etc. The introduction to the above indi- cators is put forward and their merits and demerits are analyzed. Based on the GHG emission data from the World Resource Institute （WRI）, the US Energy Information Administration （EIA）, and the Carbon Dioxide Information Analysis Center （CDIAC）, the results of each indictor are calculated for the world, for the eight G8 industrialized countries （USA, UK, Canada, Japan, Germany, France, Italy and Russia）, and the five major developing countries including China, Brazil, India, South Africa and Mexico. The paper points out that all these indicators have some limitations. The Indicator of Industrialized Accumulative Emission per Capita （IAEC） is put forward as the equitable indicator to evaluate the industrialized historical accumulative emission per capita of every country. IAEC indicator can reflect the economic achievement of GHG emission enjoyed by the current generations in every country and their commitments. The analysis of IAEC indicates that the historical accumulative emission per capita in indus- trialized countries such as UK and USA were typically higher than those of the world average and the developing countries. Emission indicator per capita per GDP, consumptive emission indicator and survival emission indicator are also put forward and discussed in the paper.

Climate Responses to Direct Radiative Forcing of Anthropogenic Aerosols,Tropospheric Ozone,and Long-Lived Greenhouse Gases in Eastern China over 1951–2000

A unified chemistry-aerosol-climate model is applied in this work to compare climate responses to changing concentrations of long-lived greenhouse gases （GHGs, CO2, CH4, N2O）, tropospheric O3, and aerosols during the years 1951-2000. Concentrations of sulfate, nitrate, primary organic carbon （POA）, secondary organic carbon （SOA）, black carbon （BC） aerosols, and tropospheric 03 for the years 1950 and 2000 are obtained a priori by coupled chemistry-aerosol-GCM simulations, and then monthly concentrations are interpolated linearly between 1951 and 2000. The annual concentrations of GHGs are taken from the IPCC Third Assessment Report. BC aerosol is internally mixed with other aerosols. Model results indicate that the sinmlated climate change over 1951-2000 is sensitive to anthropogenic changes in atmospheric components. The predicted year 2000 global mean surface air temperature can differ by 0.8℃ with different forcings. Relative to the climate simulation without changes in GHGs, O3, and aerosols, anthropogenic forcings of SO4^2-, BC, BC＋SO4^2-, BC＋SO4^2- ＋POA, BC＋SO4^2- ＋POA＋SOA＋NO3^-, O3, and GHGs are predicted to change the surface air temperature averaged over 1971-2000 in eastern China, respectively, by -0.40℃, ＋0.62℃, ＋0.18℃, ＋0.15℃, -0.78℃, ＋0.43℃, and ＋0.85℃, and to change the precipitation, respectively, by -0.21, ＋0.07, -0.03, ＋0.02, -0.24, -0.08, and ＋0.10 mm d^-1. The authors conclude that all major aerosols are as important as GHGs in influencing climate change in eastern China, and tropospheric O3 also needs to be included in studies of regional climate change in China.

A Review of Research on Human Activity Induced Climate ChangeⅠ. Greenhouse Gases and Aerosols

Extensive research on the sources and sinks of greenhouse gases, carbon cycle modeling, and the characterization of atmospheric aerosols has been carried out in China during the last 10 years or so. This paper presents the major achievements in the fields of emissions of greenhouse gases from agricultural lands, carbon cycle modeling, the characterization of Asian mineral dust, source identification of the precursors of the tropospheric ozone, and observations of the concentrations of atmospheric organic compounds. Special, more detailed Information on the emissions of methane from rice fields and the physical and chemical characteristics of mineral aerosols are presented.

Air pollutants and greenhouse gases emission inventory for power plants in the Antarctic

Emissions of air pollutants and greenhouse gases into the atmosphere in Antarctica from power plants with diesel generators(the main sources of energy at Antarctic research stations and the main stationary sources of anthropogenic emissions in the Antarctic)were assessed.A bottom-up approach was used to compile an emission inventory for the Antarctic.This involved estimating emissions at various spatial levels by sequentially aggregating estimate emissions from point emission sources.This is the first time this approach has been proposed and used.Emissions of CO2,NOx,particulate matter(PM10),and CO in the modern period were estimated at the research station,geographic region,natural domain,biogeographic region,continent section,and whole continent scales.Yearly emissions are presented here,but the approach allows emissions at different averaging periods to be estimated.This means mean or maximum yearly,monthly,daily,or hourly emissions can be estimated.The estimates could be used to model pollutant transmission and dispersion,assess the impacts of pollutants,and develop emission forecasts for various scenarios.

Progress on Monitoring Methods of Atmospheric Greenhouse Gases

There are many types of methods for monitoring atmospheric greenhouse gases,and the differences between the methods have introduced many uncertainties for the accurate monitoring of atmospheric greenhouse gases.In this paper,the monitoring methods of 7 long-lived greenhouse gases(LLGHG),including carbon dioxide(CO_(2)),methane(CH_(4)),nitrous oxide(N_(2)O),hydrofluorocarbons(HFCs),perfluorocarbons(PFCs),sulfur hexafluoride(SF_(6))and nitrogen trifluoride(NF_(3)),which are regulated and controlled in the Kyoto Protocol and the Doha Amendment,were summarized,and the principle,characteristics and application research progress of each method were systematically studied.Besides,their application scope was analyzed,and the domestication research of relevant instruments was analyzed and prospected.At present,the monitoring methods of atmospheric greenhouse gases are developing towards automation and multi-component simultaneous rapid detection,and are accelerating its integration with new technologies such as big data and satellite remote sensing monitoring;top-down and bottom-up methods are used to provide strong data support for carbon peaking and carbon neutral management decisions in various countries.

Thermal efficiency of the principal greenhouse gases

Atmospheric gases are ranked according to the efficiency with which they absorb and radiate longwave radiation. The open international HITRAN database of gaseous absorption lines of high resolution together with inverse Fourier transform were used. The autocorrelation functions of the total dipole moment of the basic greenhouse gases molecules such as H2 O,CO2, O3, N2 O, and CH4 were obtained. Absorption coefficient spectra and emission power spectra of infrared radiation of these gases were calculated. Analysis of the emissive ability of all gases under consideration was carried out. Compared to CO2, all the gases under investigation have more effective emission except ozone. An efficiency criterion of IR absorption and emission is defined and is calculated for each studied gas, and the gases are ranked accordingly as follows（from strong to weak）： H2 O, CH4, CO2, N2 O, and O3.

Research on Greenhouse Gases Emission in Rice Fields at County Level

[ Objective] The study aimed to analyze greenhouse gases emission in rice fields at county level. [ Method] Based on GIS platform of soil system and greenhouse gas emission model, CH4 and N20 emission in rice fields of Chaohu City during 1990 -2009 were studied by using rice yield, fertilizer, climate and other data. [ Result] From 1990 to 2009, annual emission of CH4 emission in rice fields of Chaohu City varied from 6.47 to 11.67 Gg, and rice area, yield and the rate of straw returning to fields were the main factors influencing CH4 emission. For instance, when the rate of straw returning to fields rose to 30% and 45% respectively, CH4 emission increased by 14.4% and 27.4% separately. Annual emission of N20 in rice fields of Chaohu City from 1990 to 2009 was 0.119 -0.217 Gg. N20 emission rose slowly during 1990 -1998, then it enhanced fast and greatly as the rapid increase of chemical fertilizer and manure in their application after 1998; it reached the maximum value in 2000, then showed a decreasing trend after 2000. Thus, controlling nitrogen input and improving the utilization rate of nitrogenous fertilizer were the fundamental ways to decrease N20 emission in rice fields. [ Conclusion] The research could provide scientific references for the establishment of measures to reduce greenhouse gases emission in rice fields.

Past, Present and Future Climatic Forcing due to Greenhouse Gases

An advanced one-dimensional radiative-convective model (RCM) is used to estimate the past, present and future climatic forcings induced by greenhouse gases of anthropogenic origin, such as CO2, CH4, N2O and CFCs, in this paper. The results show that the decadal climatic forcing for the last decade is one-order bigger than that prior to the year 1900, and in the case of no control on the emission of the greenhouse gases the climatic forcing for the year 2100 will be almost 4 times as much as now.

Microporous metal-organic framework materials for efficient capture and separation of greenhouse gases

The release of anthropogenic greenhouse gases into the atmosphere poses serious risks to the environment and human health,and is a global threat of growing concern.In order to ameliorate the greenhouse gas emission problems,the efficient capture and separation of these greenhouse gases are greatly meaningful.Metal-organic framework(MOF)materials,a relatively new kind of organic-inorganic hybrid porous materials with unique framework features,tunable pore environment and high surface areas,have been widely studied as regards their applicability to this implementation.And the well-defined structures of MOF materials greatly promote the understanding of structure-property relationships.In this review,we intend to provide a profound account of significant progress in the field of capture and separation of greenhouse gases using MOFs as adsorbents,including carbon dioxide,methane,nitrous oxide and fluorocompounds(such as perfluorocarbons,sulfur hexafluoride,hydrochlorocarbons,and hydrofluocarbons).The strategies used to realize the efficient capture and separation of greenhouse gases have been summarized,and the relationships between the frameworks,their capture and separation performances and mechanisms are discussed.Furthermore,the existing challenges and perspectives with regard to the development of MOF materials for the capture and separation of greenhouse gases and industrial practical application are outlined to further promote this very significant and active emerging topic.

Modeling the effect of time delay in implementation of mitigation policies on the control of atmospheric greenhouse gases

Mitigation of the enhanced greenhouse gas(GHG)concentrations in the Earth's atmosphere is imperative to meet the climate change mitigation objective.Governments of many countries are developing and implementing various mitigation strategies to reduce their GHG emissions.However,a time delay between the formulation and implementation of these mitigation policies can affect their effectiveness in controlling greenhouse gas levels in the atmosphere.This work presents a nonlinear mathematical model to investigate the effect of application of mitigation strategies and the delay involved in their implementation over the reduction of atmospheric greenhouse gases.In model formulation,it is assumed that the mitigation strategies work two-fold;first they reduce the GHG emission rate from the anthropogenic source and second they increase the removal rate of greenhouse gas from the atmosphere.A comprehensive stability analysis of the proposed model system is made to examine its long-term behavior.The model analysis shows that an increase in the implementation rate of mitigation strategies and their efficiencies to cut down the GHG emission rate from point sources and increase the GHG uptake rate lead to reduction in equilibrium GHG concentration.It is found that a long delay in the execution of mitigation policies can destabilize the system dynamics and leads to the generation of periodic oscillations.The expression for the threshold value of the delay parameter at which periodic oscillations arise via Hopf-bifurcation is determined.The stability and direction of bifurcating periodic solutions are discussed.A sensitivity analysis is performed to investigate the effect of changes in key parameters over system dynamics.

Greenhouse gases fluxes and soil thermal properties in a pasture in central Missouri

Fluctuations of greenhouse gases emissions and soil properties occur at short spatial and temporal scales, however, results are often reported for larger scales studies. We monitored CO2, CH4, and N2O fluxes and soil temperature （T）, thermal conductivity （K）, resistivity （R） and thermal diffusivity （D） from 2004 to 2006 in a pasture. Soil air samples for determination of CO2, CH4 and N2O concentrations were collected from static and vented chambers and analyzed within two hours of collection with a gas chromatograph. T, K, R and D were measured in-situ using a KD2 probe. Soil samples were also taken for measurements of soil chemical and physical properties. The pasture acted as a sink in 2004, a source in 2005 and again a sink of CH4 in 2006. CO2 and CH4 were highest, but N2O as well as T, K and D were lowest in 2004. Only K was correlated with C02 in 2004 while T correlated with both N2O （r = 0.76, p = 0.0001） and CO2 （r = 0.88, p = 0.0001） in 2005. In 2006, all gases fluxes were significantly correlated with T, K and R when the data for the entire year were considered. However, an in-depth examination of the data revealed the existence of month-to-month shifts, lack of correlation and differing spatial structures. These results stress the need for further studies on the relationship between soil properties and gases fluxes. K and R offer a promise as potential controlling factors for greenhouse gases fluxes in this pasture.

Impacts of greenhouse gases and anthropogenic aerosols changes on surface air temperature in East Asia under different post-pandemic period emission scenarios

In order to know how surface air temperature(SAT)changes in East Asia under different emission scenarios after the COVID-19 outbreak,we investigated the impacts of greenhouse gases(GHGs)and anthropogenic aerosols changes on SAT in East Asia by using the aerosol-climate coupled model BCC-AGCM 2.0_CUACE/Aero,combining with the post-pandemic emission scenarios proposed by Covid multi-Earth system model intercomparison project(CovidMIP scenarios for short,including fossil-fueled recovery,moderate green stimulus,strong green stimulus,hereinafter as FFF,MGG,SGG,respectively).We assessed the impacts of changes in GHGs and anthropogenic aerosols together and separately on SAT in East Asia and its typical subregions during 2020-2050.The results show that by mid-21st-century,SAT in East Asia will increase by 0.81±0.083°C under Baseline(same as SSP2-4.5 scenario,i.e.,SAT difference between 2045-2050 and 2020-2025),and there will be more intense warming in all the three scenarios in East Asia,in which the largest SAT difference(SAT-d)compared to Baseline is 0.33±0.11°C under SGG and the smallest SAT-d is 0.07±0.14°C under FFF.To further explore the mechanism of these SAT-d,we analyzed the trend of surface longwave and shortwave net radiation flux driven by GHGs and anthropogenic aerosols there.It is found that in early period(2020-2035),the role of aerosol changes is bigger than that of GHG changes in dominating SAT-d,particularly sulfate,whose reduction will become the main contributor to SAT-d by affecting the net solar flux at surface.In later period(2036-2050),because of GHGs’longer atmospheric lifetime than aerosols,the role of decreasing GHGs concentrations will determine the drop in SAT-d through affecting the net longwave flux at surface.

Anthropogenic Influence on Decadal Changes in Concurrent Hot and Dry Events over China around the Mid-1990s

The frequency and duration of observed concurrent hot and dry events(HDEs) over China during the growing season(April–September) exhibit significant decadal changes across the mid-1990s. These changes are characterized by increases in HDE frequency and duration over most of China, with relatively large increases over southeastern China(SEC), northern China(NC), and northeastern China(NEC). The frequency of HDEs averaged over China in the present day(PD,1994–2011) is double that in the early period(EP, 1964–81);the duration of HDEs increases by 60%. Climate experiments with the Met Office Unified Model(MetUM-GOML2) are used to estimate the contributions of anthropogenic forcing to HDE decadal changes over China. Anthropogenic forcing changes can explain 60%–70% of the observed decadal changes,suggesting an important anthropogenic influence on HDE changes over China across the mid-1990s. Single-forcing experiments indicate that the increase in greenhouse gas(GHG) concentrations dominates the simulated decadal changes,increasing the frequency and duration of HDEs throughout China. The change in anthropogenic aerosol(AA) emissions significantly decreases the frequency and duration of HDEs over SEC and NC, but the magnitude of the decrease is much smaller than the increase induced by GHGs. The changes in HDEs in response to anthropogenic forcing are mainly due to the response of climatological mean surface air temperatures. The contributions from changes in variability and changes in climatological mean soil moisture and evapotranspiration are relatively small. The physical processes associated with the response of HDEs to GHG and AA changes are also revealed.

Severe Global Environmental Issues Caused by Canada’s Record-Breaking Wildfires in 2023

Due to the record-breaking wildfires that occurred in Canada in 2023,unprecedented quantities of air pollutants and greenhouse gases were released into the atmosphere.The wildfires had emitted more than 1.3 Pg CO_(2)and 0.14 Pg CO_(2)equivalent of other greenhouse gases(GHG)including CH4 and N_(2)O as of 31 August.The wildfire-related GHG emissions constituted more than doubled Canada’s planned cumulative anthropogenic emissions reductions in 10 years,which represents a significant challenge to climate mitigation efforts.The model simulations showed that the Canadian wildfires impacted not only the local air quality but also that of most areas in the northern hemisphere due to long-range transport,causing severe PM_(2.5)pollution in the northeastern United States and increasing daily mean PM_(2.5)concentration in northwestern China by up to 2μg m-3.The observed maximum daily mean PM_(2.5)concentration in New York City reached 148.3μg m-3,which was their worst air quality in more than 50 years,nearly 10 times that of the air quality guideline(i.e.,15μg m-3)issued by the World Health Organization(WHO).Aside from the direct emissions from forest fires,the peat fires beneath the surface might smolder for several months or even longer and release substantial amounts of CO_(2).The substantial amounts of greenhouse gases from forest and peat fires might contribute to the positive feedback to the climate,potentially accelerating global warming.To better understand the comprehensive environmental effects of wildfires and their interactions with the climate system,more detailed research based on advanced observations and Earth System Models is essential.

Climate change and human health: Last call to arms for us

Climate change,now the foremost global health hazard,poses multifaceted challenges to human health.This editorial elucidates the extensive impact of climate change on health,emphasising the increasing burden of diseases and the exacerbation of health disparities.It highlights the critical role of the healthcare sector,particularly anaesthesia,in both contributing to and mitigating climate change.It is a call to action for the medical community to recognise and respond to the health challenges posed by climate change.

Decoupling CO2 from Climate Change

This study determines if there is a correlation between rising carbon dioxide levels and global warming. Historical data were reviewed from three different time periods spanning 500 million years. It showed that the curves and trends were too dissimilar to establish a connection. Observations from CO2/temp ratios showed that the CO2 and the temperature moved in opposite directions 42% of the time. Many ratios displayed zero or near zero values, reflecting a lack of response. As much as 87% of the ratios revealed negative or near zero values, which strongly negate a correlation. The infrared spectra showed the Greenhouse Gases had an exceptionally low absorption band between 11.67 μm to 9.1 μm, which is a zone called the infrared atmospheric window. Most of the Greenhouse Gases absorb little infrared inside that zone. And that zone is where the Earth’s surface emits almost all infrared radiation. Even with minimal absorbance, water vapor captures the most infrared radiation. It absorbs 84 times more than CO2, 407 thousand times more than methane, 452 thousand times more than ozone and 2.3 million times more than nitrous oxide. The Intergovernmental Panel on Climate Change (IPCC) and the United States EPA excluded water vapor because it was not associated with man-made activities. They reported that water vapor and clouds were simply feedback mechanisms from CO2. Clouds reflect radiation from the sun. The Northern Hemisphere is 2.7°F warmer than the Southern Hemisphere because of clouds. The world cloud cover has gone down 4.1% from 1982 to 2018. Calculations show that this could be responsible for 2.4°F of the 2.7°F. The research shows that most of the recent increase in temperature (89.9%) is because of fewer clouds.

Greenhouse Gas Emissions from Agro-Ecosystems and Their Contribution to Environmental Change in the Indus Basin of Pakistan

There is growing concern that increasing concentrations of greenhouse gases in the atmosphere have been responsible for global warming through their effect on radiation balance and temperature. The magnitude of emissions and the relative importance of different sources vary widely, regionally and locally. The Indus Basin of Pakistan is the food basket of the country and agricultural activities are vulnerable to the effects of global warming due to accelerated emissions of GHGs. Many developments have taken place in the agricultural sector of Pakistan in recent decades in the background of the changing role of the government and the encouragement of the private sector for investment in new ventures. These interventions have considerable GHG emission potential. Unfortunately, no published information is currently available on GHG concentrations in the Indus Basin to assess their magnitude and emission trends. The present study is an attempt to estimate GHG （CO2, CH4 and N2O） emissions arising from different agro-ecosystems of Indus Basin. The GHGs were estimated mostly using the IPCC Guidelines and data from the published literature. The results showed that CH4 emissions were the highest （4.126 Tg yr^-1） followed by N20 （0.265 Tg yr^-1） and CO2 （52.6 Tg yr^-1）. The sources of CH4 are enteric fermentation, rice cultivation and cultivation of other crops. N2O is formed by microbial denitrification of NO3 produced from applied fertilizer-N on cropped soils or by mineralization of native organic matter on fallow soils. CO2 is formed by the burning of plant residue and by soil respiration due to the decomposition of soil organic matter.

Petroleum substitution, greenhouse gas emissions reduction and environmental benefits from the development of natural gas vehicles in China

This study develops a bottom-up model to quantitatively assess the comprehensive effects of replacing traditional petroleum-powered vehicles with natural gas vehicles（NGVs） in China based on an investigation of the direct energy consumption and critical air pollutant（CAP） emission intensity, life-cycle energy use and greenhouse gas（GHG） emission intensity of NGV fleets. The results indicate that, on average, there are no net energy savings from replacing a traditional fuel vehicle with an NGV. Interestingly, an NGV results in significant reductions in direct CAP and life-cycle GHG emissions compared to those of a traditional fuel vehicle, ranging from 61% to 76% and 12% to 29%, respectively. Due to the increasing use of natural gas as a vehicle fuel in China（i.e. approximately 28.2 billion cubic metres of natural gas in2015）, the total petroleum substituted with natural gas was approximately 23.8 million tonnes（Mt）, which generated a GHG emission reduction of 16.9 Mt of CO2 equivalent and a CAP emission reduction of 1.8 Mt in 2015. Given the significant contribution of NGVs, growing the NGV population in 2020 will further increase the petroleum substitution benefits and CAP and GHG emission reduction benefits by approximately 42.5 Mt of petroleum-based fuel, 3.1 Mt of CAPs and 28.0 Mt of GHGs. By 2030, these benefits will reach 81.5 Mt of traditional petroleum fuel, 5.6 Mt of CAPs and 50.5 Mt of GHGs, respectively.

Grazing alters sandy soil greenhouse gas emissions in a sand-binding area of the Hobq Desert,China

Deserts are sensitive to environmental changes caused by human interference and are prone to degradation.Revegetation can promote the reversal of desertification and the subsequent formation of fixed sand.However,the effects of grazing,which can cause the ground-surface conditions of fixed sand to further deteriorate and result in re-desertification,on the greenhouse gas(GHG)fluxes from soils remain unknown.Herein,we investigated GHG fluxes in the Hobq Desert,Inner Mongolia Autonomous Region of China,at the mobile(desertified),fixed(vegetated),and grazed(re-desertified)sites from January 2018 to December 2019.We analyzed the response mechanism of GHG fluxes to micrometeorological factors and the variation in global warming potential(GWP).CO_(2)was emitted at an average rate of 4.2,3.7,and 1.1 mmol/(m^(2)•h)and N_(2)O was emitted at an average rate of 0.19,0.15,and 0.09μmol/(m^(2)•h)at the grazed,fixed,and mobile sites,respectively.Mean CH_(4) consumption was as follows:fixed site(2.9μmol/(m^(2)•h))>grazed site(2.7μmol/(m^(2)•h))>mobile site(1.1μmol/(m^(2)•h)).GHG fluxes varied seasonally,and soil temperature(10 cm)and soil water content(30 cm)were the key micrometeorological factors affecting the fluxes.The changes in the plant and soil characteristics caused by grazing resulted in increased soil CO_(2)and N_(2)O emissions and decreased CH_(4) absorption.Grazing also significantly increased the GWP of the soil(P<0.05).This study demonstrates that grazing on revegetated sandy soil can cause re-desertification and significantly increase soil carbon and nitrogen leakage.These findings could be used to formulate informed policies on the management and utilization of desert ecosystems.

Response of North Pacific Eastern Subtropical Mode Water to Greenhouse Gas Versus Aerosol Forcing

Mode water is a distinct water mass characterized by a near vertical homogeneous layer or low potential vorticity, and is considered essential for understanding ocean climate variability. Based on the output of GFDL CM3, this study investigates the response of eastern subtropical mode water （ESTMW） in the North Pacific to two different single forcings： greenhouse gases （GHGs） and aerosol. Under GHG forcing, ESTMW is produced on lighter isopycnal surfaces and is decreased in volume. Under aerosol forcing, in sharp contrast, it is produced on denser isopycnal surfaces and is increased in volume. The main reason for the opposite response is because surface ocean-to-atmosphere latent heat flux change over the ESTMW formation region shoals the mixed layer and thus weakens the lateral induction under GHG forcing, but deepens the mixed layer and thus strengthens the lateral induction under aerosol forcing. In addition, local wind changes are also favorable to the opposite response of ESTMW production to GHG versus aerosol.