Quantitative assessment of the environmental risks of geothermal energy: A review

Electrification of public buses in Jakarta, Indonesia: A life cycle study

Indonesia plans to mitigate the environmental emissions, particularly the carbon emissions, from the transport by replacing conventional buses with battery electric buses (BEBs). However, there are limited studies on the potential environmental benefits of BEBs and mostly focused on carbon emissions. In this study, the environmental impacts of adopting BEBs in Jakarta's public transportation system were examined using Life Cycle Assessment (LCA) to better understand its potential environmental impacts. Using LCA, the environmental impacts of BEBs were also compared with conventional buses across their life cycles, which included raw materials extraction until the end of life stages. The results showed diesel buses have generally lower environmental impacts than BEBs due to the high share of fossil fuels in the electricity generation in Indonesia. Scenario analysis showed that extending the life cycle, using different battery disposal methods, and using battery reuse could lead to higher environmental benefits in using BEBs. Among the scenarios considered in the study, prolonging the lifespan of the bus to 32 years, using electricity mix with a higher share of renewable energy and reusing the lithium-ion batteries, BEBs would have lesser environmental impact per kilometre. In particular, the particulate matter formation (PM2.5) dropped 21 %, while the overall life cycle of BEB using the highest renewable scenario showed an average of 25 % improvement compared to the baseline scenario regarding environmental impact.

The changing nature of groundwater in the global water cycle

In recent decades, climate change and other anthropogenic activities have substantially affected groundwater systems worldwide. These impacts include changes in groundwater recharge, discharge, flow, storage, and distribution. Climate-induced shifts are evident in altered recharge rates, greater groundwater contribution to streamflow in glacierized catchments, and enhanced groundwater flow in permafrost areas. Direct anthropogenic changes include groundwater withdrawal and injection, regional flow regime modification, water table and storage alterations, and redistribution of embedded groundwater in foods globally. Notably, groundwater extraction contributes to sea level rise, increasing the risk of groundwater inundation in coastal areas. The role of groundwater in the global water cycle is becoming more dynamic and complex. Quantifying these changes is essential to ensure sustainable supply of fresh groundwater resources for people and ecosystems.

Environmental fate and ecological impact of the potentially toxic elements from the geothermal springs

Potentially toxic elements from geothermal springs can cause significant pollution of the surrounding environment and pose potential risk to the ecosystem. The fate of potentially toxic elements in the water-soil-plant system in the Yangbajain geothermal field on the Tibetan Plateau, China was investigated to assess their impact on the eco-environment. The concentrations of Be, F, As, and Tl were highly elevated in the headwaters of the Yangbajain geothermal springs, and their concentrations in the local surface water impacted by the geothermal springs reached 8.1 μg/L (Be), 23.9 mg/L (F), 3.83 mg/L (As), and 8.4 μg/L (Tl), respectively, far exceeding the corresponding thresholds for surface and drinking water. The absence of As-Fe co-precipitation, undersaturated F-, and weak adsorption on minerals at high geothermal spring pH may be responsible for the As- and F-rich drainage, which caused pollution of local river. As concentrations in the leaves of Orinus thoroldii (Stapf ex Hemsl.) Bor were up to 42.7 μg/g (dry weight basis), which is an order of magnitude higher than the allowable limit in animal feeds. The locally farmed yaks are exposed to the excessive amount of F and As with high exposure risk through water-drinking and grass-feeding.