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A few decades ago, hydroelectric projects were considered a clean source of energy. The present study aims to assess the biomass and soil carbon (C) stock in the hydroelectric catchment in India and further, its implications to mitigate GHG emissions. The estimation depicts the low 'C' stock in the reservoir's catchment in comparison to reservoirs located globally in the same eco-region which will ultimately result in lower GHG emission in the future. Moreover, estimated total carbon density of the forest species was found as 54.92 ± 18.07 MgC.ha−1 while mean SOC was 79.64 ± 19.32 MgC.ha−1. The average total 'C' stock of Tehri hydroelectric reservoir's catchment was estimated as 134.56 MgC.ha−1. Moreover, ratios (total flooded carbon/installed capacity) comprised between 4 and304 kgC/W from the other reservoirs reported globally. These ratios are higher than the Tehri reservoir (0.28 kgC/W) as flooded area of Tehri reservoir during impoundment was 52 km2. Thus, Tehri reservoir was found to emit less GHG in time to come. The present study helps the hydropower industries, policymakers, and environmentalists in designing the catchment area treatment plan to minimize the negative impact of GHG on climate change. [ABSTRACT FROM AUTHOR]

Agroforestry has great potential for carbon (C) sequestration among different land uses of the Himalayan region, India. However, our knowledge of C sequestration in particular, agroforestry system around the world is poor. Therefore, we conducted a study to understand biomass accumulation and carbon allocation in different components of the agroforestry system. The highest stem biomass was recorded in Eucalyptus tereticornis (69.43 ± 0.90 Mg ha-1), branch biomass in Populus deltoids (5.04 ± 0.35 Mg ha-1), leaf biomass also in P. deltoids (2.21 ± 0.12 Mg ha-1), and root biomass in Albizia procera (14.01 ± 0.44 Mg ha-1). The highest (81.01%) C allocation was recorded in the stem of Toona ciliate, branch of P. deltoids (5.73%), leaves of E. tereticornis (2.93%) and root of Anthocephalus cadamba (16.83%). The highest CO2 mitigation (160.5 ± 2.55 Mg CO2 ha-1) and C sequestration (45.33 ± 0.60 Mg ha-1) were recorded in E. tereticornis. The highest wheat crop biomass (11.85 ± 0.23 Mg ha-1) and C stock (3.59 ± 0.05 Mg ha-1) were recorded in P. deltiodes. However, soil carbon stock was recorded in E. tereticornis (37.5 ± 3.52 Mg ha-1). Thus, trees on farmlands with crops are suitable for biomass production and C allocation in different components under changing climatic scenarios. [ABSTRACT FROM AUTHOR]

The present study was conducted to predict the current and future potential distribution of a tree species Pterocarpus marsupium Roxb. in Ranchi, Eastern India using ecological niche modeling. Nine environmental variables comprising of isothermality, precipitation of wettest and warmest quarter, annual temperature range, soil type, human influence index, elevation, slope and land use cover were used to model the distribution of the species. Climatic variables governed the predicted distribution of the species as they contributed 56.7% as compared to the other nonclimatic variables (43.3%). Northern parts exhibited the most suitable niche of the species as compared to south‐east and central parts that showed low probability of occurrence due to high disturbances caused by rapid urbanization as well as over exploitation of the species for timber, edible and medicinal uses. The average test area under the receiver operating curve (AUC) (0.921) as well as the partial AUC indicated good model performance. The projected change scenarios of RCP2.6, RCP4.5 and RCP6.0 for the year 2050 reveal that the climatically suitable areas will be drastically reduced in Ranchi. The population of the species is declining due to its exploitation from natural habitats for timber and medicinal uses and is listed as near‐threatened by the current IUCN‐Red lists. The findings of this paper will help to identify the potential habitats for further conservation of this near‐threatened species in the changing climatic conditions and increasing anthropogenic pressure. [ABSTRACT FROM AUTHOR]

Hydropower is one of the widely used renewable energy sources and contributing a huge share in overall electricity generation in developing countries like India. A few decades ago, hydropower reservoirs were found to be a clean source of renewable energy, but after the pre-industrial era (1990s), these reservoirs were emitting a significant amount of greenhouse gases (GHG). The GHG are contributing a huge share to the regional/global carbon budget. The current study represents the first regional review and focuses on: present scenarios of Indian hydropower, environmental issues, constraints in dam construction, identified key predictors (i.e., age, depth of reservoir) impacting GHG potential, GHG risk to reservoirs, and suggested mitigation measures to the way forward for the sustainable planning of hydropower development. The review reveals that most Indian hydropower reservoirs are coming under the low to medium GHG risk of reservoirs. Small hydropower projects (SHPs) are deliberated as a worthy alternative for the sustainable management of hydropower projects. There are still many issues associated with SHPs, which cannot be neglected completely. This study provides baseline information to the hydropower industries, policy-makers, environmentalists, and water managers to take corrective measures before impoundment of a reservoir at the regional and global scale. [Display omitted] • This is the first review summarises GHG emission from Indian Hydropower. • Indian hydropower are coming under the low to medium GHG risk of reservoirs. • Small hydro is deliberated as a worthy alternative for the sustainable management of hydropower projects. • Research is urgently needed in tropical eco-regions to know the GHG risk to reservoirs. • Proposed mitigation strategies for carbon deduction in future dam constructions. [ABSTRACT FROM AUTHOR]

Global warming impacts of N use in Indian agriculture since 1960 was estimated for 20- and 100-year time scales using equation-based empirical method. During 2014, total Warming in terms of global temperature change potential (GTP) for a 20-year time scale (GTP20) was assessed as 217.31 ± 17.74 Tg CO2e, and for a 100-year time scale (GTP100) was 217.78 ± 17.78 Tg CO2e. N2O contributed 90% and 99%of the GTP20 and GTP100, respectively. Total cooling impacts were 94.86 ± 7.75 and 50.36 ± 4.11 Tg CO2e on GTP20 and GTP100, respectively. Aerosols of NH3 and NOx, NOx-induced O3 and CH4 alteration, and N-induced C sequestration contributed 41, 6 and 51%, respectively, to GTP20, however, N-induced C sequestration contributed about 99% to GTP100. Net warming impacts were 122.45 ± 10.00 and 167.42 ± 13.67 Tg CO2e on GTP20 and GTP100, respectively. Net warming impacts were lowered by 10% and 1% compared to total warming, and 37% and 23% compared to warming caused by N2O alone, for GTP20 and GTP100, respectively. Usually, to estimate the global warming impacts of N use in agriculture, the warming effects of only N2O emission are considered. However, both warming and cooling impacts should be considered to capture the net impacts of N use in agriculture on climate change. [ABSTRACT FROM AUTHOR]