Though, the attention of researchers on exploring the impact of economic policy uncertainty on carbon emissions is on increase, however, the impact of different types of economic policy uncertainty remains unexplored. Thus, this study investigates the impact of different types of economic policy uncertainty on carbon emissions in Japan. A monthly data from 1987M1 to 2019M12 was used, while the FMOLS, DOLS, CCR and ARDL estimators were employed for examining the cointegration among the variables, as well as the long- and short-run relationship between types of economic policy uncertainty and carbon emissions. The study findings revealed a long-run cointegration among energy consumption, per capita income, fiscal, exchange rate, monetary, and trade policy uncertainties and carbon emissions. Moreover, this study found energy consumption, exchange rate, monetary, and trade policy uncertainties to contribute significantly to the increase of carbon emissions in Japan. Finally, this study suggests that environmental policy makers in Japan should take into account the economic policy uncertainty so as to promote robust information for climate policy that will be targeted at ameliorating the carbon emissions in Japan.

Ugii Lake is a freshwater lake located in the steppe region of Mongolia and is an important breeding and staging area for a wide variety of waterfowl. Remote sensing and geographic information system techniques were used to estimate fluctuations in the surface area and water balance of Ugii Lake. To estimate the changes in lake water balance, lake water fluctuations should be analyzed using the most accurate methods. A different water extraction technique was applied, and the results were compared with field surveys conducted in May, July, and September 2020. The lake surface area using both NDWI and MNDWI-1 showed a strong, positive correlation (R=0.93, R=0.94, p < 0.01) with the water level of Ugii Lake. A topographic map of Ugii Lake was provided by the project (P2018-3568) conducted in August 2019 and used to estimate the volume of Ugii Lake in ArcGIS 10.1. This result was consistent with that of a previous study by JICA in 2005. Finally, the water balance of Ugii Lake was estimated, and the results proved that the influence of both surface and groundwater on Ugii Lake are valuable parameters, which are completely dependent on hydrological regime changes mostly due to local climate change in steppe regions. This study provides valuable insight into the most suitable water extraction methods for lakes in semi-arid steppe regions in Mongolia.

Considerable amounts of previously deposited persistent organic pollutants (POPs) are stored in the Arctic cryosphere. Transport of freshwater and terrestrial material to the Arctic Ocean is increasing due to ongoing climate change and the impact this has on POPs in marine receiving systems is unknown This study has investigated how secondary sources of POPs from land influence the occurrence and fate of POPs in an Arctic coastal marine system.Passive sampling of water and sampling of riverine suspended particulate matter (SPM) and marine sediments for analysis of polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) was carried out in rivers and their receiving fjords in Isfjorden system in Svalbard. Riverine SPM had low contaminant concentrations (<level of detection-28 pg/g dw ΣPCB₁₄, 16–100 pg/g dw HCB) compared to outer marine sediments 630-880 pg/g dw ΣPCB₁₄, 530–770 pg/g dw HCB). There was a strong spatial gradient in sediment PCB and HCB concentrations with lowest concentrations in river estuaries and in front of marine-terminating glaciers and increasing concentrations toward the outer fjord. This suggests that rather than leading to increased concentrations, inputs of SPM from land lead to a dilution of contaminant concentrations in nearshore sediments. Preliminary estimates of SPM:water activity ratios suggest that terrestrial particles (with low contaminant concentrations) may have the potential to act as sorbents of dissolved contaminants in the coastal water column, with implications for bioavailability of POPs to the marine food web. There is concern that ongoing increases in fluxes of freshwater, sediments and associated terrestrial material (including contaminants) from land to the Arctic Ocean will lead to increased mobilization and transport of POPs to coastal ecosystems. However, the results of this study indicate that on Svalbard, inputs from land may in fact have the opposite effect, leading to reduced concentrations in coastal sediments and waters.

In this review, global change processes have been linked to polycyclic aromatic compounds (PACs) in Canada and a first national budget of sources and sinks has been derived. Sources are dominated by wildfire emissions that affect western and northern regions of Canada disproportionately due to the location of Pacific and boreal forests and the direction of prevailing winds. Wildfire emissions are projected to increase under climate warming along with releases from the thawing of glaciers and permafrost. Residential wood combustion, domestic transportation and industry contribute the bulk of anthropogenic emissions, though they are substantially smaller than wildfire emissions and are not expected to change considerably in coming years. Other sources such as accidental spills, deforestation, and re-emission of previous industrial deposition are expected to contribute anthropogenic and biogenic PACs to nearby ecosystems. PAC sinks are less well-understood. Atmospheric deposition is similar in magnitude to anthropogenic sources. Considerable knowledge gaps preclude the estimation of environmental transformations and transboundary flows, and assessing the importance of climate change relative to shifts in population distribution and energy production is not yet possible. The outlook for PACs in the Arctic is uncertain due to conflicting assessments of competing factors and limited measurements, some of which provide a baseline but have not been followed up in recent years. Climate change has led to an increase in primary productivity in the Arctic Ocean, but PAC-related impacts on marine biota appear to be modest. The net effect of changes in ecological exposure from changing emissions and environmental conditions throughout Canada remains to be seen. Evidence suggests that the PAC budget at the national scale does not represent impacts at the local or regional level. The ability to assess future trends depends on improvements to Canada’s environmental measurement strategy and biogeochemical modelling capability.

Atmospheric aerosols play a crucial role in climate change, especially in the Himalayas and Tibetan Plateau. Here, we present the seasonal and diurnal characteristics of aerosol vertical profiles measured using a Mie lidar, along with surface black carbon (BC) measurements, at Mt. Qomolangma (QOMS), in the central Himalayas, in 2018–2019. Lidar-retrieved profiles of aerosols showed a distinct seasonal pattern of aerosol loading (aerosol extinction coefficient, AEC), with a maximum in the pre-monsoon (19.8 ± 22.7 Mm⁻¹ of AEC) and minimum in the summer monsoon (7.0 ± 11.2 Mm⁻¹ of AEC) seasons. The diurnal variation characteristics of AEC and BC were quite different in the non-monsoon seasons with enriched aerosols being maintained from 00:00 to 10:00 in the pre-monsoon season. The major aerosol types at QOMS were identified as background, pollution, and dust aerosols, especially during the pre-monsoon season. The occurrence of pollution events influenced the vertical distribution, seasonal/diurnal patterns, and types of aerosols. Source contribution of BC based on the weather research and forecasting chemical model showed that approximately 64.2% ± 17.0% of BC at the QOMS originated from India and Nepal in South Asia during the non-monsoon seasons, whereas approximately 47.7% was from local emission sources in monsoon season. In particular, the high abundance of BC at the QOMS in the pre-monsoon season was attributed to biomass burning, whereas anthropogenic emissions were the likely sources during the other seasons. The maximum aerosol concentration appeared in the near-surface layer (approximately 4.3 km ASL), and high concentrations of transported aerosols were mainly found at 4.98, 4.58, 4.74, and 4.88 km ASL in the pre-monsoon, monsoon, post-monsoon, and winter seasons, respectively. The investigation of the vertical profiles of aerosols at the QOMS can help verify the representation of aerosols in the air quality model and satellite products and regulate the anthropogenic disturbance over the Tibetan Plateau.

Marine atmospheric aerosols play important roles in the global radiation balance and climate change. Hence, measuring physiochemical aerosol properties is essential to better understand their formation, aging processes, and source origins. However, high temporal resolution measurements of submicron particles are currently scarce in the northern South China Sea (SCS). In this study, we conducted a ship-based cruise campaign with a scanning mobility particle sizer and an online time of flight aerosol chemical speciation monitor to measure the particle number size distribution (PNSD) and the chemical composition of submicron particles over the northern SCS during summer 2018. The mean concentration of non-refractory submicron particulate matter (NR-PM₁) was generally 9.11 ± 4.86 μg m⁻³; sulfate was the most abundant component, followed by organics, ammonium, nitrate, and chloride. Positive matrix factorization (PMF) analysis was applied to the PNSD (size PMF) and organic aerosols (OA PMF) and further investigated the source apportionment of the submicron particles. The size PMF identified four factors, including ship exhaust, ship influencing marine primary, continent affected marine secondary, and mixed accumulation aerosols. The most abundant particles in the number concentration were associated with ship emissions, which accounted for approximately 44 %. The submicron organic aerosols were highly oxidized and composed of low-volatility oxygenated OA (LV-OOA, 68 %), semi-volatile OOA (SV-OOA, 21 %), and hydrocarbon-like OA (HOA, 11 %). The backward trajectory of air masses showed that the northern SCS was most frequently (64.7 %) influenced by air masses from the Indo-Chinese Peninsula (ICP) during the campaign, implying that pollutants from ICP have a significant impact on the atmosphere of the northern SCS during summer. Thus, in situ ship-based cruise measurements can provide valuable data on the physiochemical characteristics of marine atmospheric aerosols to better understand their source origins.

Fluorescence spectroscopy is a commonly used technique to analyze dissolved organic matter in aquatic environments. Given the high sensitivity and non-destructive analysis, fluorescence has recently been used to study water-soluble organic carbon (WSOC) in atmospheric aerosols, which have substantial abundance, various sources and play an important role in climate change. Yet, current research on WSOC characterization is rather sparse and limited to a few isolated sites, making it challenging to draw fundamental and mechanistic conclusions. Here we presented a review of the fluorescence properties of atmospheric WSOC reported in various field and laboratory studies, to discuss the current advances and limitations of fluorescence applications. We highlighted that photochemical reactions and relevant aging processes have profound impacts on fluorescence properties of atmospheric WSOC, which were previously unnoticed for organic matter in aquatic environments. Furthermore, we discussed the differences in sources and chemical compositions of fluorescent components between the atmosphere and hydrosphere. We concluded that the commonly used fluorescence characteristics derived from aquatic environments may not be applicable as references for atmospheric WSOC. We emphasized that there is a need for more systematic studies on the fluorescence properties of atmospheric WSOC and to establish a more robust reference and dataset for fluorescence studies in atmosphere based on extensive source-specific experiments.

China has been famous for its porcelains for millennia, and the combustion processes of porcelain production emit substantial amounts of air pollutants, which have not been well understood. This study provided firsthand data of air pollutant emissions from biomass porcelain kilns. The emission factor of PM₂.₅ was 0.95 ± 1.23 g/kg during the entire combustion cycle, lower than that of biomass burning in residential stoves and coal burning in brick kilns, attributed to the removal effects of the long-distance transport in dragon kilns. The temporal trend of particle pollutants, including particulate matters (PMs) and particulate polycyclic aromatic hydrocarbons (PAHs) (low at ignition phase and high at the end) again indicated the removal effects of the special structure, while gaseous pollutants, such as gaseous PAHs, exhibited the opposite result. The GWC₁₀₀ was estimated as 1.4 × 10⁶ and 0.5 × 10⁶ kg CO₂e/yr for the scenarios in which 50% and 100% of the wood was renewable, respectively. The GWC₁₀₀ of dragon kilns is nearly equal to that of 745 households using wood-fueled stoves. These results indicate the necessity of pollution controls for biomass porcelain kilns to estimate the emission inventory and climate change.

Cyclophosphamide (CP) is an antineoplastic drug widely used in chemotherapy treatments with high consumption rates and that has been detected in the aquatic environment. After being released into the aquatic environment, CP may cause adverse effects on aquatic organisms since antineoplastics are well-known cytotoxic, genotoxic, mutagenic and teratogenic drugs. Moreover, predicted environmental changes, such as the temperature rising, may alter the impacts caused by CP on organisms. Thus, the present study aimed to assess the effects caused by CP chronic exposure in the mussel Mytilus galloprovincialis, under actual and predicted warming scenarios. Organisms were exposed for 28 days to different concentrations of CP (10, 100, 500 and 1000 ng/L) at control (17 ± 1.0 °C) and increased (21 ± 1.0 °C) temperatures. Biochemical responses related to metabolic capacity, energy reserves, oxidative stress and neurotoxicity were assessed. The results showed that the organisms were able to maintain their metabolic capacity under all exposure conditions. However, their antioxidant defense mechanisms were activated mostly at higher CP concentrations being able to prevent cellular damage, even under the warming scenario. Overall, the present findings suggest that temperature rise may not alter the impacts of CP towards M. galloprovincialis.

While the influence of climate change on the fate of persistent organic pollutants (POPs) is becoming a topic of global concern, it has yet to be demonstrated how POPs and their transformation products in soil respond to a changing climate at the local scale. We conducted a year-long field experiment with spiked soils to investigate the impact of climate on the dissipation of γ-hexachlorocyclohexane (γ-HCH) and p,p’-dichlorodiphenyltrichloroethane (p,p’-DDT) as well as the formation of their products. Four sites along an elevational gradient on the eastern Tibetan Plateau were selected to represent four scenarios ranging from a dry and cold to a warm and humid climate. Based on the measured concentrations of the two pesticides and their transformation products, we calculated the dissipation rates of γ-HCH and p,p’-DDT in soil using two biphasic kinetic models, and the formation rates of transformation products using a mid-point rectangular approximation method. The spiked γ-HCH generally showed the expected decrease in dissipation from soils with increasing altitudes, and therefore decreasing temperature and precipitation, whereas dissipation of p,p’-DDT was influenced more by photolysis and sequestration in soil. The formation rates of the primary products of γ-HCH (i.e. γ-HCH→PeCCH and γ-HCH→TeCCH) and p,p’-DDT (i.e. p,p’-DDT→p,p’-DDE and p,p’-DDT→p,p’-DDD) indicate that a warmer and wetter climate favors dechloroelimination (anaerobic biodegradation) over dehydrochlorination (aerobic biodegradation). The significantly longer dissipation half-lives of γ-HCH at the coldest site suggests that the fate of POPs in frozen regions (e.g. polar regions) needs more attention. Overall, the fate of more volatile chemicals (e.g. γ-HCH) might be more responsive to the climate change.