RESUMO
The objective of this research is to examine the relationship between transport energy consumption, economic growth, and carbon dioxide emission (CO2) from transport sector incorporating foreign direct investment and urbanization. This study is carried out in Pakistan by applying autoregressive distributive lag (ARDL) and vector error correction model (VECM) over 1990-2015. The empirical results indicate a strong significant impact of transport energy consumption on CO2 emissions from the transportation sector. Furthermore, foreign direct investment also contributes to CO2 emission. Interestingly, the impact of economic growth and urbanization on transport CO2 emission is statistically insignificant. Overall, transport energy consumption and foreign direct investment are not environmentally friendly. The new empirical evidence from this study provides a complete picture of the determinants of emissions from the transport sector and these novel findings not only help to advance the existing literature but also can be of special interest to the country's policymakers. So, we urge that government needs to focus on promoting the energy efficient means of transportation to improve environmental quality with less adverse influence on economic growth.
Assuntos
Dióxido de Carbono/análise , Desenvolvimento Econômico/estatística & dados numéricos , Internacionalidade , Investimentos em Saúde , Paquistão , UrbanizaçãoRESUMO
Sunflower (Helianthus annuus L.) is the leading non-conventional oilseed crop in Pakistan. Nitrogen fertilizer can affect plant growth and productivity by changing canopy size which has an effect on the radiation use efficiency (RUE) of the crop. The response of sunflower hybrids in terms of phenology, fraction of intercepted radiation (F i), and RUE to nitrogenous rates (0, 60, 120, 180, and 240 kg ha-1) was studied in three field experiments conducted in three various environments: Multan (arid), Faisalabad (semi-arid), and Gujranwala (sub-humid) during spring seasons 2008 and 2009. The treatments were laid out according to a randomized complete block design with split plot arrangements, keeping the sunflower hybrids in main plots and nitrogen rates in sub-plots, and replicated three times. The results showed Hysun-38 took a maximum number of days to anthesis (101) as compared to Pioneer-64A93 (100) and Hysun-33 (99). The mean values of F i were 0.850, 0.903, and 0.978, and the estimated values of RUE for total aboveground dry matter were 2.14, 2.47, and 2.65 g MJ-1 at experimental locations of Multan, Faisalabad, and Gujranwala, respectively. The values of RUE for grain yield (RUEGY) were 0.78, 0.98, and 1.26 g MJ-1 at experimental locations of Multan, Faisalabad, and Gujranwala, respectively. The average RUEGY values over three locations were 2.61, 2.60, 2.43, and 2.36 g MJ-2 in N4 (180 kg ha-1), N5 (240 kg ha-1), N3 (120 kg ha-1), and N2 (60 kg ha-1) treatments, respectively. Increasing rates of N increased RUEGY over the standard treatment N3 (120 kg N ha-1); however, the averaged values over three locations were 1.22, 1.08, 0.99, and 0.92 g MJ-2 in N4, N5, N3, and N2 treatments, respectively. Therefore, optimum water and N doses are important for attaining higher RUE, which may enhance sunflower growth and yield.