Suchergebnisse

The area with the highest concentration of carbon emission activities is construction land. However, few studies have been conducted that investigated the different effects of various types of construction land on carbon emissions and the extent of their impact. To address this shortcoming, this study constructed a multi-indicator evaluation system with 393 counties in Southwest China and integrated ordinary least squares and spatial regression models to deeply analyze the different impacts of construction land types on carbon emissions. The results revealed that (1) in Southwest China, carbon emissions were generally distributed in clusters, with significant spatial variability and dependence; (2) the distribution of urban land scale, rural settlement land scale, and other construction land scale all showed obvious spatial clustering differences; (3) all three types of construction land's effect on carbon emissions was positive, and the direction of impact was in line with theoretical expectations; and (4) the other construction land scale had the highest effect on carbon emissions, followed by rural settlement land scale, while the urban land scale was slightly lower. The findings help to further explain the different impacts of construction land types on carbon emissions and provide theoretical references for the government to formulate more refined emissions reduction policies.

Farmers in China and many other developing countries suffer from low technical efficiency of chemical fertilizer use, which leads to excessive nutrient runoff and other environmental problems. A major cause of the low efficiency is lack of science-based information and recommendations for nutrient application. In response, the Chinese government launched an ambitious nationwide program called the "Soil Testing and Fertilizer Recommendation Project" (STFRP) in 2005 to increase the efficiency of chemical fertilizer use. However, there has been no systematic evaluation of this program. Using data from a nationally representative household survey, and using wheat as an example, this paper first quantifies the technical efficiency of chemical fertilizer use (TEFU) by conducting stochastic frontier analysis (SFA), then evaluates the impact of STFRP on the TEFU using a generalized difference-in-difference approach. We found that STFRP, on average, increased TEFU in wheat production by about 4%, which was robust across various robustness checks. The lessons learned from STFRP will be valuable for China's future outreach efforts, as well as for other countries considering similar nutrient management policies.