AbstractAerosol optical depth (AOD) is a principal indicator used to describe the atmospheric condition and effect of aerosols on radiative transfer in the Earth's atmosphere. In this study, the spatial-temporal variation of AOD of the Yangtze Delta during 2000–2011 and the impact of land cover were studied. The results show that Moderate Resolution Imaging Spectroradiometer (MODIS) AOD was in good agreement with data obtained from six ground-based Aerosol Robotic Network (AERONET) sun photometers (R > 0.75). The AOD over the Yangtze Delta presented an obvious one year cycle variation from 2000 to 2011. The largest value often appeared in May or June, and the smallest often appeared in December or January. The AOD over main cities has increased gradually over the years. The AOD over urban areas increased faster than that in rural areas. A change of land-use/cover leads to a change of AOD. Areas of land-use/cover with increased intense human activity leads to changes in higher AOD whereas an increase in forested areas leads to an AOD change to a lower value. Forest land has a purification effect against atmospheric aerosols.
OPS 02: Environmental epidemiology and policy, Room 315, Floor 3, August 28, 2019, 1:30 PM - 3:00 PM Background: Opponents of climate policy sometimes claim that climate change does not exist, or that warming will not be harmful. A common counterargument is that reducing emissions may be desirable for other reasons, including to obtain the health 'co-benefits' that may result from improved air quality. Studies have confirmed that the health co-benefits of achieving climate targets may be large, but these scenario-based investigations do not fully answer the question of whether health benefits alone justify meaningful climate action, in part because they do not account for different ways of achieving those benefits. Methods: We use the RICE+AIR cost-benefit model to estimate the optimal climate policy when the climate benefits are zero, thus computing the level of CO2 reductions ('decarbonization') that would be best according to a policy perspective where air pollution is harmful but climate change is not. We perform these calculations for two different background assumptions. In one, only planned air quality policies are implemented in the future. In the other, future air quality policy is jointly optimized with climate policy to compute the genuinely co-optimal policy mix given the comparative costs of each. Results: If air quality policy proceeds approximately as planned, some decarbonization is warranted for air quality reasons, even though climate benefits are disregarded. However, the decarbonization is not sufficient to limit climate change to 2°C, as only ~50% of the necessary reductions in CO2 are achieved over the next century. Furthermore, a large proportion of the associated health benefits may be achieved at lower cost through end-of-pipe air quality technologies. Results are somewhat sensitive to assumptions about how to value life-years. Conclusions: Our study confirms the need to jointly optimize air quality and climate policy options in order to take the harms from climate change and the benefits from clean air fully into account.
This paper uses a 10 years monitoring data set of 100 counties to examine the process, implementation and impacts of China’s Conversion of Cropland to Forests Program (CCFP). A theoretical framework was constructed to explain the development of CCFG. We find that CCFG was originate from economic growth and will fulfill its goal by economic growth as it closely linked with rural poverty; Constrains such as income decline will finally be solved along with policy adjustment and economic growth; Huge amount of subsidies had been successfully delivered to farmers under strong administration and innovative policy; due to incentive incompatibility between farmers’ private interests and public benefit, we assume that CCFG only achieved second best ecological goals, but a better sustainability. The policy still faces many uncertainties due to climate change, rural development progress, et al.
Ground-level ozone is a secondary pollutant produced by photochemical reactions and it adversely affects plant and human health. Taiyuan City, a typical city on the loess plateau, is suffering from severe ozone pollution. We utilized the data from eight national environmental monitoring sites of Taiyuan, including concentrations of O3 and nitric oxide, and meteorological factors, such as air temperature and wind, to study the pollution characteristics and sources of ozone (O3) in Taiyuan in 2018. Results show that during 2018, the maximum value and 90th percentile of the maximum 8-h running average of O3 concentration were 257 μg/m3 and 192 μg/m3, respectively. There were 72 days where the O3 concentration exceeded the standard in 2018, which were mainly during April to August. The O3 concentration increased from March, reached a high level in April through August, and decreased significantly from September. The O3 concentrations displayed a typical “single peak” diurnal variation, which was high during the day with peak at around 13:00–15:00 and low at night. From April to August, the O3 concentrations at Jinyuan was the highest, followed by Xiaodian and Taoyuan, and the O3 concentrations at Shanglan and Nanzhai were the lowest. When the O3 concentration exceeded the standard value, Jinyuan contributed the most to the O3 pollution of Taiyuan, followed by Taoyuan and Xiaodian. High temperature and pressure, south and southwest winds can lead to an increase in O3 concentration. The O3 pollution in the Taiyuan urban area is caused by local generation, and the transportation of polluted air masses containing oxides of nitrogen (NOx) and volatile organic compounds (VOCs) emitted by industries, such as the coking and steel plants in counties of Jinzhong City in southern Taiyuan, and Qingxu County, and some counties in Lyuliang City to the southwest. In addition, the mountain winds and low nitric oxide concentration are the main reasons for the increase of O3 concentration, often observed in Shanglan at night.
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