Suchergebnisse

As the world's largest carbon emitter, China is under great pressure to cut down carbon emissions. Understanding the evolution of carbon emissions across Chinese cities is important for policymakers when allocating carbon emission quota among these cities. This paper draws upon the Open-source Data Inventory for Anthropogenic CO2 to calculate city-level per capita carbon emissions in China from 2001 to 2016. Overall, we find that per capita carbon emissions of Chinese cities have been generally on the rise during the 2001–2016 period. However, there has been on average a modest decline in per capita carbon emissions of cities in China's Yangtze River Delta region and Pearl River Delta region from 2011 to 2016, after a remarkable increase during the 2001–2011 period. Besides, the average north-south gap has been enlarged, with northern cities having a relatively higher level of per capita carbon emissions.

Car-dominated daily travel has caused many severe and urgent urban problems across the world, and such travel patterns have been found to be related to the built environment. However, few existing studies have uncovered the nonlinear relationship between the built environment and car dependency using a machine learning method, thus failing to provide policymakers with nuanced evidence-based guidance on reducing car dependency. Using data from Puget Sound regional household travel surveys, this study analyzes the complicated relationship between car dependency and the built environment using the gradient boost decision tree method. The results show that people living in high-density areas are less likely to rely on private cars than those living in low-density neighborhoods. Both threshold and nonlinear effects are observed in the relationships between the built environment and car dependency. Increasing road density promotes car usage when the road density is below 6 km/km2. However, the positive association between road density and car use is not observed in areas with high road density. Increasing pedestrian-oriented road density decreases the likelihood of using cars as the main mode. Such a negative effect is most effective when the pedestrian-oriented road density is over 14.5 km/km2. More diverse land use also discourages people's car use, probably because those areas are more likely to promote active modes. Destination accessibility has an overall negative effect and a significant threshold effect on car dependency. These findings can help urban planners formulate tailored land-use interventions to reduce car dependency.

Shale gas development throughout the world has resulted in a revolution in the field of global energy and has also become an important topic in China in recent years. While organic-rich shale is widely distributed in China and the initial commercialization of shale gas has been achieved, the research, exploration, and development of shale gas remain at an early stage. Problems exist with crucial technologies, innovation, institutional mechanisms, environmental protection, and other aspects of the industry. The shale gas exploration and development industry in China can learn from the experiences of other countries and strengthen its position in the market, with the support of new government policy. Given its unique geological conditions, China should speed up the introduction of technical innovation and establish its unique systems and methods for shale gas exploration and development. ; El desarrollo del gas de lutita en el mundo ha significado una revolución en el campo de la energía; en China, durante los útlimos años se ha convertido en un tema importante. Las lutitas, ricas organicámente, están ampliamente distribuidas en China y la comercilización inicial de gas de lutita ha sido lograda; sin embargo, la investigación, exploración y desarrollo de este producto permanence en etapas prematuras. Los problemas se presentan en las tecnologías clave, la innovación, los mecanismos institucionales, la protección ambiental y otros aspectos de la industria. La exploración del gas de lutita y el desarrollo industrial en China se pueden mejorar a partir de las experiencias de otros países y con su fortalecimiento en el mercado, acompañado del apoyo de políticas gubernamentales. Gracias a sus condiciones geológicas únicas, China puede acelerar la introducción de innovación técnica y establecer sus sistemas y métodos únicos para la exploración y desarrollo del gas de lutita.