Using two equivalent descriptions of the shale gas development process, we asked individuals to indicate their levels of support as well as their perceptions of the risks and costs involved. In version 1, shale gas development was framed as ‘fracking’, whereas under version 2 it was framed as ‘using hydraulic pressure to extract natural gas from the ground’. We find that individuals’ support for shale gas development is much lower when using the term ‘fracking’ as opposed to the synonymous descriptive term, and moreover, these differences were substantive. Our analysis suggests that these differences appear to be largely the result of different assessments of the risks associated with ‘fracking’ as opposed to ‘using hydraulic pressure to extract natural gas from the ground’. Our proposed explanation for these differences rests on the idea that shale gas development is a technical and complex process and many individuals will be bounded by the rationality of scientific knowledge when it comes to understanding this process. In turn, individuals may be relying on simple decision heuristics shaped by the way this issue is framed by the media and other interested parties which may constrain meaningful discourse on this topic with the public. Our findings also highlight some of the potential pitfalls when it comes to relying on survey research for assessing the public’s views towards complex environmental issues.

Despite the increasing attention on renewable energy, still there is limited empirical analysis about its determinants especially in developing countries. In this paper, we investigate the determinants of diversification of nonhydro renewable energy sources such as wind, solar, geothermal, biomass and waste using an extensive data set covering more than 100 developing countries from 1980 to 2010. We explore several estimation techniques such as negative binomial regression and Poisson pseudo-maximum likelihood estimation. Controlling for time and regional variations, results show that higher per capita income, implementation of renewable energy policy, advances in technological innovation and improvement in human capital promotes diversification of nonhydro sources of renewable energy. However, financial development showed no robust evidence of its effect on the diversification. Similarly, high dependence on foreign sources of fuel, increasing world market price for crude oil and increasing population will push developing countries to diversify sources of nonhydro renewable energy. In contrast, the local abundance of hydropower, high production of fossil fuel, development aid and foreign direct investment do not contribute to diversification. Results highlight salient information in drawing the roadmap for further diffusion of renewable energy in developing countries. This suggests that policy makers should exert consistent effort in integrating renewable energy in the country’s energy mix.

This study investigates the thermochemical properties of the separate components of jatropha biomass residues of Nigerian origin towards bio-oil production. The biomass residues (Jatropha curcas fruit shells and seed coat) were obtained from their mature jatropha fruits and subjected to physico-chemical characterization (structural composition analysis, thermogravimetric analysis, proximate and ultimate analyses). The structural compositions (extractives, hemicellulose, cellulose and lignin contents) of jatropha fruit shell and jatropha seed coat were 3%, 34.0%, 40.0% and 12.7%, and 42.3%, 32.5%, 10.5% and 5.7%, respectively. The thermogravimetric analysis showed that the ash contents of jatropha seed coat and jatropha fruit shell were 0.8% and 15.4%, respectively. The carbon contents were 48.3% and 41.5%, while measured calorific values were 20.06 MJ/kg and 17.14 MJ/kg for jatropha seed coat and fruit shell, respectively. The carbon, hydrogen, nitrogen and sulphur contents were found comparable with those in the literature. This study indicated that the thermochemical properties of the Nigerian Jatropha fruit and seeds residues were comparable with literature values and residues were found suitable for bio-oil production.

Energy has been playing a pivotal role in the progress and prosperity of a nation. Growing demands with dwindling stock of fossil fuels with the associated greenhouse gas (GHG) footprint and the consequent changes in the climate during the post-industrialization era have necessitated the exploration for sustainable energy alternatives. Biofuels are gaining importance as viable alternatives to fossil fuels during the last decade. Microalgae, especially diatoms, have shown prospects to be viable third-generation biofuel feedstocks, due to its higher lipid productivity, shorter cycling time and ubiquitous presence. This investigation focuses on identifying robust diatom strains that can sustain the vagaries of nature and yield higher lipid. This would avert the imminent risks of contamination associated with pure cultures and higher costs. The current research involved inventorying diatom consortia across diverse lentic and lotic habitats of the Aghanashini estuary with varied levels of nutrients primarily influenced by distribution of flora and fauna to understand the role of environmental parameters and nutrient levels in species composition, community structure. This effort is an essential prelude to phyco-prospecting potential candidates for third-generation biofuel production. The results obtained from the present study provide insights into an optimal habitat conditions, more specifically ideal nutrient concentrations for enhanced growth of different clusters of diatoms, a determining factor for higher biomass and lipid productivity. Multivariate statistical analyses revealed an occurrence of 27 tolerant diatoms species belonging to genera’s Amphora, Cyclotella, Navicula, Nitzschia and Pleurosigma. Linkages of the dominant and productive clusters of diatoms with habitat nutrient concentrations were investigated through agglomerative hierarchical clustering. Probable empirical relationship among varying environmental conditions and corresponding lipid content of diatoms were explored through regression analyses. Investigations of species tolerant to higher nutrient loads and assessment of lipid aided in prioritizing the strains with benefits of phyco-remediation as well as prospects of biofuel.

Land use changes have been recognized as one of the key ecological drivers in regulation of methane (CH₄) consumption from dry upland soils. This study investigated the impact of land use changes and different soil depths (0–10, 10–20 and 20–30 cm) on soil physicochemical properties and methanotrophs abundance in dry tropical region of Vindhyan uplands. Four different land use types (agriculture land, mixed forest, savanna and natural forest) were selected for a comparative study. Among the different land uses and soil depths, results indicated significantly higher soil moisture (SM), organic-C, inorganic nutrients, water holding capacity (WHC) and methanotrophs abundance at 0–10 cm depth of natural forest compared to other sites. Across different land uses, number (8.11 × 10⁷ pmoA copies g⁻¹ of dry soil) of methanotrophs isolated from the natural forest soil was statistically higher than the soils of other land use types. The variations in pmoA gene numbers across different land uses and soil depths were significant (P < 0.001). The pmoA gene numbers were positively correlated with soil C/N ratio (R ² = 0.9233) and moisture (R ² = 0.9675) contents. The decreasing order of pmoA gene abundance across different land uses was natural forest > mixed forest > savanna > agriculture land. The result suggest that land use changes (conversion of natural forest to agricultural land) alter the major soil properties (SM, WHC, organic matter, C/N ratio, etc.) and significantly reduce the methanotrophs and pmoA gene numbers. The land use management practices (application of bio-fertilizers in place of chemical fertilizers), especially for the degraded agricultural soils, could be beneficial option to mitigate the negative impacts on soil methanotrophs and their CH₄ sink activity in the upland soil of Vindhyan region.