PNNL

Abstract

Anthropogenic climate change is exacerbating water scarcity in Mediterranean climate regions, such as Central Chile, which already has a low annual precipitation rate, increasing the likelihood of a potentially permanent “mega-drought”. While carbon neutrality policies are critical to combating this trend, their cross-sectoral impacts within the water-energy-land nexus require further exploration and remain poorly understood. This study takes a closer look at how Chile’s carbon neutrality pathway to 2050 may influence existing water challenges at the country scale by employing the Global Change Analysis Model (GCAM), an integrated human-earth system model. Our scenarios consider one business as usual and eight alternative pathways to carbon neutrality focused on both energy sector decarbonization and land-sector mitigation. Findings indicate that renewable energy-led decarbonization substantially reduces electricity-sector water withdrawals by decoupling power generation from thermal cooling demand, offering direct water co-benefits in a water-scarce context. However, total water withdrawals remain dominated by agricultural irrigation, which continues to grow under all scenarios. Land-sector mitigation reduces irrigation demand by constraining agricultural production, but introduces trade-offs with food production. The implications of these interactions could instigate a new policy landscape of water-energy-land interactions in Chile's near future, necessitating further attention to nexus implications of climate policies in water-scarce contexts.