Air pollution is one of the grand environmental challenges in developing countries, especially those with high population density like China. High concentrations of primary and secondary trace gases and particulate matter (PM) are frequently observed in the industrialized and urbanized regions, causing negative effects on the health of humans, plants, and the ecosystem. Meteorological conditions are among the most important factors influencing day-to-day air quality. Synoptic weather and boundary layer dynamics control the dispersion capacity and transport of air pollutants, while the main meteorological parameters, such as air temperature, radiation, and relative humidity, influence the chemical transformation of secondary air pollutants at the same time. Intense air pollution, especially high concentration of radiatively important aerosols, can substantially influence meteorological parameters, boundary layer dynamics, synoptic weather, and even regional climate through their strong radiative effects. As one of the main monsoon regions, with the most intense human activities in the world, East Asia is a region experiencing complex air pollution, with sources from anthropogenic fossil fuel combustion, biomass burning, dust storms, and biogenic emissions. A mixture of these different plumes can cause substantial two-way interactions and feedbacks in the formation of air pollutants under various weather conditions. Improving the understanding of such interactions needs more field measurements using integrated multiprocess measurement platforms, as well as more efforts in developing numerical models, especially for those with online coupled processes. All these efforts are very important for policymaking from the perspectives of environmental protection and mitigation of climate change.
Aijun Ding, Xin Huang, and Congbin Fu
Ecotourism is responsible travel to natural areas that educates and inspires through interpretation—increasingly paired with practical action—that helps conserve the environment and sustain the well-being of local people. Ecotourism is the fastest-growing segment of the travel and tourism industry, and its economic value is projected to exceed USD$100 billion by 2027. Ecotourism emerged in the 1960s as a response to the destructive effects of mass tourism and has been embraced by an increasing number of governments, especially in the developing world, as a vehicle for achieving the UN Sustainable Development Goals. As an emerging, interdisciplinary field of study, ecotourism has reached a critical inflection point, as scholars reflect on the achievements and shortcomings of several decades of research and set out the research agenda for decades to come. The field has yet to achieve consensus on the most basic questions, such as how ecotourism is, or should be, defined; what makes it different from nature-based and related forms of tourism; and what factors ultimately determine the success or failure of ecotourism as a vehicle for sustainable development. This lack of consensus stems in part from the different perspectives and agendas within and between the academic, policy, and industry communities. Because it is based on measured and observed phenomena, empirical research has a critical role to play in advancing the theory and practice of ecotourism. However, scholars also recognize that to fulfill this role, methodologies must evolve to become more longitudinal, scalable, inclusive, integrative, and actionable.
Isabela Espindola and Pilar Villar
The sharing of transboundary water resources, whether surface or groundwater, is a significant challenge, both in theory and practice. Countries in situations of sharing these natural resources are predisposed to interact with each other. These interactions, here called transboundary water interactions, are characterized by the coexistence of cooperation and conflict, which can arise at different governance levels. However, negotiations around transboundary water resources primarily occur between diplomats and high government members from riparian countries and river basin organization (RBO) managers. Transboundary water negotiations are usually considered high-level political discussions, given the complexity and scale of the water challenges. Consequently, decision-making processes incorporate only a limited number of participants, who make decisions capable of impacting the entire population that depend on the shared waters. Over the last 20 years, there has been a need for greater transparency and a participatory process in transboundary water negotiations, especially for local community engagement and collaboration in these processes. Many of the negotiation processes around transboundary water resources need the participation of municipalities and local populations, concomitant with the involvement of RBOs, to carry out decisions to manage transboundary waters in an integrated manner. There are several reasons for this demand, including negotiation effectiveness, contestation prevention, data sharing, ensuring continuing participation and collaboration, and promoting public awareness related to water resources. Discussing social participation, particularly in the management of transboundary water resources, requires attention to the historical context and its constraints. Considering the enormous challenge, the experiences of local community engagement in transboundary water negotiations in South America, especially from the Guarani Aquifer and the La Plata Basin, are good examples for improving this discussion around transboundary water interactions and local community engagement. The La Plata Basin is the second-largest transboundary basin in the continent, shared by Argentina, Bolivia, Brazil, Uruguay, and Paraguay, while the Guarani Aquifer is one of the largest reservoirs of freshwater worldwide, shared by Argentina, Brazil, Paraguay, and Uruguay. Even with both having cooperation agreements in place between the riparian states, there are still great difficulties with regard to the participation of local communities in transboundary water negotiations.