Controlling biodiversity impacts of future global hydropower reservoirs by strategic site selection

New indicator of habitat functionality reveals high risk of underestimating trade-offs among sustainable development goals: The case of wild reindeer and hydropower

Although biodiversity is crucial for Sustainable Development Goals (SDGs), following the current trajectory, we risk failing SDG 15. Using a new indicator quantifying the loss of functional habitat (habitat that is simultaneously suitable and well-connected), we show that the real impact of renewable energy is far larger than previously assumed. Specifically, we estimate that the construction of hydropower reservoirs in south Norway caused a loss of ca. 222 km² of functional habitat for wild reindeer (Rangifer tarandus)-which is far larger than assumed based on land inundation indices (110 km²). Fully mitigating these impacts is challenging: scenario analyses reveal that the measures proposed by societal actors would yield only a fraction of the habitat lost (2-12 km²) and could cause trade-off risks with other SDGs. Using indices of functional connectivity is crucial for environmental impact assessments, as entire ecological networks for several species can be affected far beyond the reservoirs.

Analyzing the impact of energy consumption, the democratic process, and government service delivery on life expectancy: evidence from a global sample

Life expectancy is one of the crucial criteria for determining the quality of life in today's societies. As such, the study of factors affecting life expectancy is a key issue for policymakers. This study aims to investigate the impact of energy consumption, the democratic process, and government service delivery on life expectancy in 100 countries during 2000-2018, using panel quantile regression. The impact of these factors on life expectancy has been estimated in quantiles of 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 0.95. Also, the impact of GDP, CO₂ emission, and Gini coefficient variables has been explored as controlling variables on life expectancy. The results show that the impact of CO₂ emissions and the democratic process on life expectancy is negative in all quantiles, and the impact of GDP is negative in all quantiles except 0.95. Moreover, the relationship between hydroelectricity consumption and life expectancy in the 0.05, 0.1, 0.2, 0.8, and 0.9 quantiles is negative and significant. Accordingly, based on the results, the impact of petroleum and other liquids consumption, government service delivery, and Gini coefficient on life expectancy in all quantiles is positive and only the impact of the Gini coefficient on life expectancy in all quantiles is significant.

River ecosystem endangerment from climate change-driven regulated flow regimes

Major threats of freshwater systems are river damming and habitat degradation, further amplified by climate change, another major driver of biodiversity loss. This study aims to understand the effects of climate change, and its repercussions on hydropower production, on the instream biota of a regulated river. Particularly, it aims to ascertain how mesohabitat availability downstream of hydropower plants changes due to modified flow regimes driven by climate change; how mesohabitat changes will influence the instream biota; and if instream biota changes will be similar within and between biological groups. We used a mesohabitat-level ecohydraulic approach with four biological elements - macrophytes, macroalgae, diatoms and macroinvertebrates - to encompass a holistic ecosystem perspective of the river system. The ecological preferences of the biological groups for specific mesohabitats were established by field survey. The mesohabitat availability in three expected climate change-driven flow regime scenarios was determined by hydrodynamic modeling. The biota abundance/cover was computed for the mesohabitat indicator species of each biological group. Results show that climate-changed flow regimes are characterized by a significant water shortage during summer months already for 2050. Accordingly, the regulated rivers' hydraulics are expected to change towards more homogeneous flow conditions where run habitats should prevail. As a result, the biological elements are expected to face abundance/cover modifications ranging from decreases of 76% up to 67% increase, depending on the biological element and indicator taxa. Diatoms seem to endure the greatest range of modifications while macrophytes the slightest (15% decrease to 38% increase). The greatest modifications would occur on decreasing abundance/cover responses. Such underlies an important risk to fluvial biodiversity in the future, indicting climate change as a significant threat to the fluvial system in regulated rivers.