The rise of the modern economy centered upon knowledge, knowledge workers, and knowledge artifacts has brought with it the promise of technological growth and innovation, but also new challenges in political governance and economic development. Maintaining the proper incentives for knowledge creation against the necessity of a broad information commons is a delicate compromise on both a domestic scale with various private and public interests, as well on an international one with developed states and developing states. The strength and scope of intellectual property regimes directly affect this balance of interests. As they are developed and revised for the modern age, these regimes raise broad implications for the health and future of the global knowledge economy.
The Chinese government launched the Air Pollution Prevention and Control Action Plan in 2013, and various stringent measures have since been implemented, which have resulted in significant decreases in emissions and ambient concentrations of primary pollutants such as SO2, NOx, and particulate matter (PM). However, surface ozone (O3) concentrations have still been increasing in urban areas across the country. In a previous analysis, we examined in detail the roles of meteorological variation during 2013–2017 in the summertime surface O3 trend in various regions of China. In this study, we evaluated the effect of changes in multi-pollutant emissions from anthropogenic activities on O3 levels during the same period by using an up-to-date regional chemical transport model (WRF-CMAQ) driven by an interannual anthropogenic emission inventory. The Community Multiscale Air Quality (CMAQ) model was improved with regard to heterogeneous reactions of reactive gases on aerosol surfaces, which led to better model performance in reproducing the ambient concentrations of those gases. The model simulations showed that the maximum daily 8 h average (MDA8) O3 mixing ratio in urban areas increased by 0.46 ppbv per year (ppbv a−1) (p=0.001) from 2013 to 2017. In contrast, a slight decrease in MDA8 O3 by 0.17 ppbv a−1 (p=0.005) in rural areas was predicted, mainly attributable to the NOx emission reduction. The effects of changes in individual pollutant emissions on O3 were also simulated. The reduction of NOx emission increased the O3 levels in urban areas due to the nonlinear NOx and volatile organic compound (VOC) chemistry and decreasing aerosol effects; the slight increase in VOC emissions enhanced the O3 levels; the reduction of PM emissions increased the O3 levels by enhancing the photolysis rates and reducing the loss of reactive gases on aerosol surfaces; and the reduction of SO2 emissions resulted in a drastic decrease in sulfate concentrations, which increased O3 through aerosol effects. In contrast to the unfavorable effect of the above changes in pollutant emissions on efforts to reduce surface O3, the reduction of CO emissions did help to decrease the O3 level in recent years. The dominant cause of increasing O3 due to changes in anthropogenic emissions varied geographically. In Beijing, NOx and PM emission reductions were the two largest causes of the O3 increase; in Shanghai, the reduction of NOx and increase in VOC emissions were the two major causes; in Guangzhou, NOx reduction was the primary cause; in Chengdu, the PM and SO2 emission decreases contributed most to the O3 increase. Regarding the effects of decreasing concentrations of aerosols, the drop in heterogeneous uptake of reactive gases – mainly HO2 and O3 – was found to be more important than the increase in photolysis rates. The adverse effect of the reductions of NOx, SO2, and PM emissions on O3 abatement in Beijing, Shanghai, Guangzhou, and Chengdu would have been avoided if the anthropogenic VOCs emission had been reduced by 24 %, 23 %, 20 %, and 16 %, respectively, from 2013 to 2017. Our analysis revealed that the NOx reduction in recent years has helped to contain the total O3 production in China. However, to reduce O3 levels in major urban and industrial areas, VOC emission controls should be added to the current NOx-SO2-PM policy.
China has suffered from increasing levels of ozone pollution in urban areas despite the implementation of various stringent emission reduction measures since 2013. In this study, we conducted numerical experiments with an up-to-date regional chemical transport model to assess the contribution of the changes in meteorological conditions and anthropogenic emissions to the summer ozone level from 2013 to 2017 in various regions of China. The model can faithfully reproduce the observed meteorological parameters and air pollutant concentrations and capture the increasing trend in the surface maximum daily 8-hour average (MDA8) ozone (O 3 ) from 2013 to 2017. The emission control measures implemented by the government induced a decrease in MDA8 O3 levels in rural areas but an increase in urban areas. The meteorological influence on the ozone trend varied by region and by year and could be comparable to or even more significant than the impact of changes in anthropogenic emissions. Meteorological conditions can modulate the ozone concentration via direct (e.g., increasing reaction rates at higher temperatures) and indirect (e.g., increasing biogenic emissions at higher temperatures) effects. As an essential source of volatile organic compounds that contributes to ozone formation, the variation in biogenic emissions during summer varied across regions and was mainly affected by temperature. China's midlatitude areas (25° N to 40° N) experienced a significant decrease in MDA8 O 3 due to a decline in biogenic emissions, especially for the Yangtze River Delta and Sichuan Basin regions in 2014 and 2015. In contrast, in northern (north of 40° N) and southern (south of 25° N) China, higher temperatures after 2013 led to an increase in MDA8 O 3 concentrations via an increase in biogenic emissions. We also assessed the individual effects of changes in temperature, specific humidity, wind field, planetary boundary layer height, clouds, and precipitation on ozone levels from 2013 to 2017. The results show that the wind field change made a significant contribution to the increase in surface ozone over China by transporting the ozone downward from the upper troposphere and the lower stratosphere. The long-range transport of ozone and its precursors outside the modeling domain also contributed to the increase in MDA8 O 3 in China, especially on the Tibetan Plateau (an increase of 1 to 4 ppbv). Our study represents the most comprehensive and up-to-date analysis of the impact of changes in meteorology on ozone across China and highlights the importance of considering meteorological variations when assessing the effectiveness of emission control on changes in the ozone levels in recent years.
The Chinese government launched the Air Pollution Prevention and Control Action Plan in 2013, and various stringent measures have since been implemented, which have resulted in significant decreases in emissions and ambient concentrations of primary pollutants such as SO 2 , NO x , and particulate matter (PM). However, surface ozone (O 3 ) concentrations have still been increasing in urban areas across the country. In a previous analysis, we examined in detail the roles of meteorological variation during 2013–2017 in the summertime surface O 3 trend in various regions of China. In this study, we evaluated the effect of changes in multi-pollutant emissions from anthropogenic activities on O 3 concentrations during the same period, by using an up-to-date regional chemical transport model (WRF-CMAQ) driven by an interannual anthropogenic emission inventory. The CMAQ model was improved with regard to heterogeneous reactions of reactive gases on aerosol surfaces, which led to better model performance in reproducing the ambient concentrations of those gases. The model simulations showed that the maximum daily 8-hour average (MDA8) O 3 concentration in urban areas increased by 0.46 ppbv per year (ppbv a -1 ) (p = 0.001) from 2013 to 2017. In contrast, a slight decrease in MDA8 O 3 concentrations by 0.17 ppbv a -1 (p = 0.005) in rural areas was predicted, mainly attributable to the NO x emission reduction. The effects of changes in individual pollutant emissions on O 3 were also simulated. The reduction of NO x emission increased the O 3 concentration in urban areas due to the non-linear NO x -volatile organic compound (VOC) chemistry and decreasing aerosol effects; the slight increase in VOCs emissions enhanced the O 3 concentrations; the reduction of PM emissions increased the O 3 concentrations by enhancing the photolysis rates and reducing the loss of reactive gases on aerosol surfaces; and the reduction of SO 2 emissions resulted in a drastic decrease in sulfate concentrations, which increased the O 3 concentrations through aerosol effects. In contrast to the unfavorable effect of the above changes in pollutant emissions on efforts to reduce surface concentrations of O 3 , the reduction of CO emissions did help to decrease the O 3 concentrations in recent years. The dominant cause of increasing O 3 concentrations due to changes in anthropogenic emission varied geographically. In Beijing, NO x and PM emission reductions were the two largest causes of the O 3 increase; in Shanghai, the reduction of NO x and increase in VOC emissions were the two major causes; in Guangzhou, NO x reduction was the primary cause; and in Chengdu, the PM and SO 2 emission decreases contributed most to the O 3 concentration increase. Regarding the effects of decreasing concentrations of aerosols, the drop in heterogeneous uptake of reactive gases – mainly HO 2 and O 3 – was found to be more important than the increase in photolysis rates. The adverse effect of the reductions of NO x , SO 2 , and PM emissions on O 3 abatement in Beijing, Shanghai, Guangzhou, and Chengdu would have been avoided if the anthropogenic VOCs emission had been reduced by 24 %, 23 %, 20 %, and 16 %, respectively, from 2013 to 2017. Our analysis revealed that the NO x reduction in recent years has helped to contain the total O 3 production in China. However, to reduce O 3 concentrations in major urban and industrial areas, VOCs emissions control should be added to the current NO x -SO 2 -PM policy.
The Chinese government launched the Air Pollution Prevention and Control Action Plan in 2013, and various stringent measures have since been implemented, which have resulted in significant decreases in emissions and ambient concentrations of primary pollutants such as SO 2 , NO x , and particulate matter (PM). However, surface ozone ( O 3 ) concentrations have still been increasing in urban areas across the country. In a previous analysis, we examined in detail the roles of meteorological variation during 2013–2017 in the summertime surface O 3 trend in various regions of China. In this study, we evaluated the effect of changes in multi-pollutant emissions from anthropogenic activities on O 3 levels during the same period by using an up-to-date regional chemical transport model (WRF-CMAQ) driven by an interannual anthropogenic emission inventory. The Community Multiscale Air Quality (CMAQ) model was improved with regard to heterogeneous reactions of reactive gases on aerosol surfaces, which led to better model performance in reproducing the ambient concentrations of those gases. The model simulations showed that the maximum daily 8 h average (MDA8) O 3 mixing ratio in urban areas increased by 0.46 ppbv per year ( ppbv a −1 ) ( p =0.001 ) from 2013 to 2017. In contrast, a slight decrease in MDA8 O 3 by 0.17 ppbv a −1 ( p =0.005 ) in rural areas was predicted, mainly attributable to the NO x emission reduction. The effects of changes in individual pollutant emissions on O 3 were also simulated. The reduction of NO x emission increased the O 3 levels in urban areas due to the nonlinear NO x and volatile organic compound (VOC) chemistry and decreasing aerosol effects; the slight increase in VOC emissions enhanced the O 3 levels; the reduction of PM emissions increased the O 3 levels by enhancing the photolysis rates and reducing the loss of reactive gases on aerosol surfaces; and the reduction of SO 2 emissions resulted in a drastic decrease in sulfate concentrations, which increased O 3 through aerosol effects. In contrast to the unfavorable effect of the above changes in pollutant emissions on efforts to reduce surface O 3 , the reduction of CO emissions did help to decrease the O 3 level in recent years. The dominant cause of increasing O 3 due to changes in anthropogenic emissions varied geographically. In Beijing, NO x and PM emission reductions were the two largest causes of the O 3 increase; in Shanghai, the reduction of NO x and increase in VOC emissions were the two major causes; in Guangzhou, NO x reduction was the primary cause; in Chengdu, the PM and SO 2 emission decreases contributed most to the O 3 increase. Regarding the effects of decreasing concentrations of aerosols, the drop in heterogeneous uptake of reactive gases – mainly HO 2 and O 3 – was found to be more important than the increase in photolysis rates. The adverse effect of the reductions of NO x , SO 2 , and PM emissions on O 3 abatement in Beijing, Shanghai, Guangzhou, and Chengdu would have been avoided if the anthropogenic VOCs emission had been reduced by 24 %, 23 %, 20 %, and 16 %, respectively, from 2013 to 2017. Our analysis revealed that the NO x reduction in recent years has helped to contain the total O 3 production in China. However, to reduce O 3 levels in major urban and industrial areas, VOC emission controls should be added to the current NO x - SO 2 -PM policy.
Governments across the world have implemented restrictive policies to slow the spread of COVID-19. Recommended face mask use has been a controversially discussed policy, among others, due to potential adverse effects on physical distancing. Using a randomized field experiment (N = 300), we show that individuals kept a significantly larger distance from someone wearing a face mask than from an unmasked person during the early days of the pandemic. According to an additional survey experiment (N = 456) conducted at the time, masked individuals were not perceived as being more infectious than unmasked ones, but they were believed to prefer more distancing. This result suggests that wearing a mask served as a social signal that led others to increase the distance they kept. Our findings provide evidence against the claim that mask use creates a false sense of security that would negatively affect physical distancing. Furthermore, our results suggest that behavior has informational content that may be affected by policies. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40881-021-00108-6.
