A rapid transition to renewable energy sources is widely regarded as imperative for addressing global climate change. Countries are increasingly drawing upon hydropower to reduce emissions from energy systems, however much of this untapped potential is in hyperdiverse river basins. While hydropower could help advance net zero commitments, dams have been a main driver of biodiversity loss in Earth’s freshwaters, and their continued proliferation could further put decarbonization and biodiversity conservation goals at odds.
Here we quantify tradeoffs emerging between biodiversity, greenhouse gas emissions and energy generation in the context of expanding hydropower development. We focus our analysis on 18 eco-sensitive river basins located across South America, Africa and Asia with high biodiversity, and where hydropower features prominently in national strategies to reduce carbon emissions from energy systems. We adopt a new AI-driven multi-objective decision-making framework to find the full Pareto frontier: the set of hydropower project portfolios that maximize aggregate energy production while minimizing negative impacts across a set of environmental objectives.
We find that portfolios that maximize energy generation while minimizing impacts on biodiversity can emit 50% more carbon per unit electricity generated than those that minimize emissions from hydropower projects. Considering that carbon is fungible, while biodiversity is not, we propose that the price of carbon can be leveraged to catalyze an offset market for biodiversity in the context of net-zero commitments. Offsetting emissions from biodiversity-centered planning would only cost 0.5 U$ MWh-1, or 0.5% of the levelized cost of hydroelectricity. Our analysis uncovers an extraordinary opportunity to leverage the carbon market to both minimize fish biodiversity impacts of hydropower proliferation and minimize emissions with little loss in economic competitivity.