The global gasoline and diesel fuel vehicle fleets impose substantial impacts on air quality, human health, and climate change. Here we quantify the global radiative forcing and human health impacts ...of the global gasoline and diesel sectors using the NCAR CESM global chemistry‐climate model for year 2015 emissions from the IIASA GAINS inventory. Net global radiative effects of short‐lived climate forcers (including aerosols, ozone, and methane) from the gasoline and diesel sectors are +13.6 and +9.4 mW m−2, respectively. The annual mean net aerosol contributions to the net radiative effects of gasoline and diesel are −9.6 ± 2.0 and +8.8 ± 5.8 mW m−2. Aerosol indirect effects for the gasoline and diesel road vehicle sectors are −16.6 ± 2.1 and −40.6 ± 4.0 mW m−2. The fractional contributions of short‐lived climate forcers to the total global climate impact including carbon dioxide on the 20‐year time scale are similar, 14.9% and 14.4% for gasoline and diesel, respectively. Global annual total PM2.5‐ and ozone‐induced premature deaths for gasoline and diesel sectors approach 115,000 (95% CI: 69,000–153,600) and 122,100 (95% CI: 78,500–157,500), with corresponding years of life lost of 2.10 (95% CI: 1.23–2.66) and 2.21 (95% CI: 1.47–2.85) million years. Substantial regional variability of premature death rates is found for the diesel sector when the regional health effects are normalized by the annual total regional vehicle distance traveled. Regional premature death rates for the gasoline and diesel sectors, respectively, vary by a factor of eight and two orders of magnitude, with India showing the highest for both gasoline and diesel sectors.
Plain Language Summary
Emissions from the global transportation system play an important role in affecting our air quality, climate change, and public health. We use an advanced chemistry‐climate model to estimate the effects of tailpipe emissions from the gasoline and diesel vehicle fuel types on changes in Earth's energy budget, and premature deaths associated with respiratory and cardiovascular diseases. Our results show that the climatic effects of both gasoline and diesel vehicle fleets, including carbon dioxide, are warming. The fractional contributions from short‐lived climate forcers (including aerosols, ozone, and methane) relative to the total radiative effects including carbon dioxide for the gasoline and diesel sectors on a 20‐year time scale are 14.9% and 14.4%, respectively. Global annual total premature deaths of 115,000 and 122,100 are attributable to the gasoline and diesel sectors. We also analyze the regional premature death rates, which are calculated as ratios of annual total regional premature deaths to annual total regional vehicle distance traveled for each vehicle fuel type. Our study finds that there exists substantial regional variability of premature death rates for the diesel sector, with India showing the highest compared with other regions.
Key Points
The net radiative effects for the gasoline and diesel sectors over a 20‐year time scale are +91.4 and +65.7 mW m−2, respectively
Global annual total premature deaths of 115,000 and 122,100 are attributable to the gasoline and diesel sectors
There exists substantial regional variability of premature death rates for the diesel sector
There is an increasing need for computer science and engineering (CSE) online education. This study examined CSE online learners’ perceptions of self-directed learning (SDL) readiness, strategies, ...and satisfaction. The researchers surveyed 225 students and conducted semi-structured interviews with 15 online CSE students. The quantitative survey data and the qualitative interview data were analyzed using descriptive statistics and thematic analysis, respectively. The findings were as follows: (1) Both extrinsic motivation strategies (e.g., future career development, building a learning routine) and intrinsic motivation strategies (e.g., interest in learning) were utilized; (2) Diverse metacognition strategies (e.g., assignments, quizzes, and tests, discussing with peers, tracking progress, staying in touch with professors and teaching assistants) and cognitive strategies (e.g., watching recorded lectures, taking notes, reading books, seeking out information) were used to monitor learning; (3) Time-management (e.g., priority, checklist, fixed schedule, time-block for study) and resource management strategies (e.g., focused on lectures, textbook reading) were leveraged; (4) Specific designs or instruction promoted students’ SDL skills, such as access to documented learning materials, reminders sent from instructors, availability of the instructor, group interaction, and flexibility, and (5) Student satisfaction depended on the design of the course. The advantages and disadvantages of online learning were identified. The findings indicated that the instruction strategies and online course design are critical for CSE students’ SDL.
Abstract Outdoor air pollution, particularly volatile organic compounds (VOCs), significantly contributes to the global health burden. Previous analyses of VOC exposure have typically focused on ...regional and national scales, thereby limiting global health burden assessments. In this study, we utilized a global chemistry-climate model to simulate VOC distributions and estimate related cancer risks from 2000 to 2019. Our findings indicated a 10.2% rise in global VOC emissions during this period, with substantial increases in Sub-Saharan Africa, the Rest of Asia, and China, but decreases in the U.S. and Europe due to reductions in the transportation and residential sectors. Carcinogenic VOCs such as benzene, formaldehyde, and acetaldehyde contributed to a lifetime cancer burden affecting 0.60 95% confidence interval (95CI): 0.40–0.81 to 0.85 95CI: 0.56–1.14 million individuals globally. We projected that between 36.4% and 39.7% of the global population was exposed to harmful VOC levels, with the highest exposure rates found in China (82.8–84.3%) and considerably lower exposure in Europe (1.7–5.8%). Open agricultural burning in less-developed regions amplified VOC-induced cancer burdens. Significant disparities in cancer burdens between high-income and low-to-middle-income countries were identified throughout the study period, primarily due to unequal population growth and VOC emissions. These findings underscore health disparities among different income nations and emphasize the persistent need to address the environmental injustice related to air pollution exposure.
Global economic development and urbanization during the past two decades have driven the increases in demand of personal and commercial vehicle fleets, especially in developing countries, which has ...likely resulted in changes in year-to-year vehicle tailpipe emissions associated with aerosols and trace gases. However, long-term trends of impacts of global gasoline and diesel emissions on air quality and human health are not clear. In this study, we employ the Community Earth System Model in conjunction with the newly developed Community Emissions Data System as anthropogenic emission inventory to quantify the long-term trends of impacts of global gasoline and diesel emissions on ambient air quality and human health for the period of 2000–2015. Global gasoline and diesel emissions contributed to regional increases in annual mean surface PM2.5 (particulate matter with aerodynamic diameters ⩽2.5 μm) concentrations by up to 17.5 and 13.7 µg m−3, and surface ozone (O3) concentrations by up to 7.1 and 7.2 ppbv, respectively, for 2000–2015. However, we also found substantial declines of surface PM2.5 and O3 concentrations over Europe, the US, Canada, and China for the same period, which suggested the co-benefits of air quality and human health from improving gasoline and diesel fuel quality and tightening vehicle emissions standards. Globally, we estimate the mean annual total PM2.5- and O3-induced premature deaths are 139 700–170 700 for gasoline and 205 200–309 300 for diesel, with the corresponding years of life lost of 2.74–3.47 and 4.56–6.52 million years, respectively. Diesel and gasoline emissions create health-effect disparities between the developed and developing countries, which are likely to aggravate afterwards.
Global solid biofuel stove emissions strongly impact air quality, climate change, and human health. However, investigations of the impacts of global solid biofuel stove emissions on human health ...associated with PM2.5 (particulate matter with aerodynamic diameter ≤2.5 μm) and ozone (O3) are limited. Here, we quantify the impacts of global solid biofuel stove emissions on ambient PM2.5 and O3 air quality and the associated human health effects for the year 2010, using the Community Atmosphere Model coupled with Chemistry version 5.3. Annual mean surface PM2.5 concentrations from global solid biofuel stove emissions averaged over 2006–2010 are up to 23.1 μg m−3, with large impacts found over China, India, sub‐Saharan Africa, and eastern and central Europe. For surface O3 impacts, we find that global solid biofuel stove emissions lead to increases in surface O3 concentrations by up to 5.7 ppbv for China, India, and sub‐Saharan Africa, and negligible impacts or reductions of up to 0.5 ppbv for the US, Europe, and parts of South America. Global solid biofuel stove emissions for the year 2010 contribute to 382,000 95% confidence interval (95CI): 349,000–409,000 annual premature deaths associated with PM2.5 and O3 exposure, with the corresponding years of life lost as 8.10 million years (95CI: 7.38–8.70 million years). Our study highlights air quality and human health benefits of mitigating emissions from the global solid biofuel stove sector, especially over populous regions of low‐income and middle‐income countries, through promoting clean household energy programs for the residential energy supply.
Plain Language Summary
Ambient air pollutant emissions from global solid biofuel stove sector, including trace gases and aerosols, play a vital role in our surface air quality associated with particulate matter and ozone, which subsequently adversely impact human health. In this study, we employ a global chemistry‐climate model to simulate the effects of global solid biofuel stove emissions on ambient air quality and human health. Our study finds that global solid biofuel stove emissions contribute significantly to surface PM2.5 and ozone air quality over China, India, and sub‐Saharan Africa. In addition, annual total PM2.5‐induced and ozone‐induced premature deaths of ∼382,000 are attributable to the global solid biofuel stove emissions. Our study highlights the air quality and human health benefits by promoting clean household energy globally for the residential energy supply over low‐income and middle‐income countries, especially over those populous regions.
Key Points
Solid biofuel stove emissions contribute significantly to surface ambient air quality over China, India, and sub‐Saharan Africa
Globally 382,000 annual premature deaths are attributable to ambient PM2.5 and ozone exposure from solid biofuel stove emissions
Promoting clean household energy programs over low‐income and middle‐income countries to improve air quality and human health is recommended
PM2.5, inhalable particles, with a size of 2.5 micrometers or less, negatively impact the environment as well as our health. Monitoring PM2.5 is critical to guard against extreme events by alerting ...people and initiating actions to alleviate PM2.5′s impacts. Developing PM2.5 forecasting frameworks empowers the authorities to predict extremely polluted events in advance and gives them time to implement necessary strategies in advance (e.g., Action! Days). Understanding the spatiotemporal behavior of PM2.5 and meteorological factors is of significance for having accurate predictions. This study utilizes EPA sensor data to quantify the PM2.5 air quality index (AQI) and meteorological factors such as temperature over 2015–2019 across Michigan, USA. Here, a spatiotemporal deep neural structure is proposed through integrating graph convolutional neural (GCN) and exogenous long short-term memory (E-LSTM) networks to incorporate spatial and temporal patterns within PM2.5 AQI and meteorological factors for predicting PM2.5 AQI. Results illustrate that not only does our proposed framework outperform the traditional approaches such as LSTM and E-LSTM, but also it is robust against the network structure of EPA stations. The study's findings demonstrate that the integration of GCN with E-LSTM significantly enhances the accuracy of PM2.5 AQI predictions compared to traditional models. This advancement indicates a promising direction for environmental monitoring, offering improved forecasting tools that can aid in timely and effective decision-making for air quality management and public health protection.
The Michigan–Ontario Ozone Source Experiment (MOOSE) is an international air quality field study that took place at the US–Canada Border region in the ozone seasons of 2021 and 2022. MOOSE addressed ...binational air quality issues stemming from lake breeze phenomena and transboundary transport, as well as local emissions in southeast Michigan and southern Ontario. State-of-the-art scientific techniques applied during MOOSE included the use of multiple advanced mobile laboratories equipped with real-time instrumentation; high-resolution meteorological and air quality models at regional, urban, and neighborhood scales; daily real-time meteorological and air quality forecasts; ground-based and airborne remote sensing; instrumented Unmanned Aerial Vehicles (UAVs); isotopic measurements of reactive nitrogen species; chemical fingerprinting; and fine-scale inverse modeling of emission sources. Major results include characterization of southeast Michigan as VOC-limited for local ozone formation; discovery of significant and unaccounted formaldehyde emissions from industrial sources; quantification of methane emissions from landfills and leaking natural gas pipelines; evaluation of solvent emission impacts on local and regional ozone; characterization of the sources of reactive nitrogen and PM2.5; and improvements to modeling practices for meteorological, receptor, and chemical transport models.
The partitioning of available energy between sensible heat and latent heat is important for precise water resources planning and management in the context of global climate change. Land surface ...temperature (LST) is a key variable in energy balance process and remotely sensed LST is widely used for estimating surface heat fluxes at regional scale. However, the inequality between LST and aerodynamic surface temperature (Taero) poses a great challenge for regional heat fluxes estimation in one-source energy balance models. To address this issue, we proposed a One-Source Model for Land (OSML) to estimate regional surface heat fluxes without requirements for empirical extra resistance, roughness parameterization and wind velocity. The proposed OSML employs both conceptual VFC/LST trapezoid model and the electrical analog formula of sensible heat flux (H) to analytically estimate the radiometric-convective resistance (rae) via a quartic equation. To evaluate the performance of OSML, the model was applied to the Soil Moisture-Atmosphere Coupling Experiment (SMACEX) in United States and the Multi-Scale Observation Experiment on Evapotranspiration (MUSOEXE) in China, using remotely sensed retrievals as auxiliary data sets at regional scale. Validated against tower-based surface fluxes observations, the root mean square deviation (RMSD) of H and latent heat flux (LE) from OSML are 34.5 W/m2 and 46.5 W/m2 at SMACEX site and 50.1 W/m2 and 67.0 W/m2 at MUSOEXE site. The performance of OSML is very comparable to other published studies. In addition, the proposed OSML model demonstrates similar skills of predicting surface heat fluxes in comparison to SEBS (Surface Energy Balance System). Since OSML does not require specification of aerodynamic surface characteristics, roughness parameterization and meteorological conditions with high spatial variation such as wind speed, this proposed method shows high potential for routinely acquisition of latent heat flux estimation over heterogeneous areas.
The occurrence of wildfires is very sensitive to fire meteorology, vegetation type and coverage. We investigate the potential impacts of global change (including changes in climate, land use/land ...cover, and population density) on wildfire frequencies over the period of 2000–2050. We account for the impacts associated with the changes in fire meteorology (such as temperature, precipitation, and relative humidity), vegetation density, as well as lightning and anthropogenic ignitions. Fire frequencies under the 2050 conditions are projected to increase by approximately 27% globally relative to the 2000 levels. Significant increases in fire occurrence are calculated over the Amazon area, Australia and Central Russia, while Southeast Africa shows a large decreasing trend due to significant increases in land use and population. Changes in fire meteorology driven by 2000–2050 climate change are found to increase the global annual total fires by around 19%. Modest increases (∼4%) in fire frequency at tropical regions are calculated in response to climate-driven changes in lightning activities, relative to the present-day levels. Changes in land cover by 2050 driven by climate change and increasing CO2 fertilization are expected to increase the global wildfire occurrences by 15% relative to the 2000 conditions while the 2000–2050 anthropogenic land use changes show little effects on global wildfire frequency. The 2000–2050 changes in global population are projected to reduce the total wildfires by about 7%. In general, changes in future fire meteorology plays the most important role in enhancing the future global wildfires, followed by land cover, lightning activities and land use while changes in population density exhibits the opposite effects during the period of 2000–2050.
•We investigate the potential impacts of global change on wildfire frequencies.•We account for changing fire meteorology, lightning, population, land use/land cover.•Fire frequencies are projected to increase by ∼27% due to 2000–2050 global change.•Fire meteorology change is the most important factor, followed by land cover.
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