资源环境科技发展态势分析平台

The Paris Agreement requires countries to articulate nearterm emissions reduction strategies through to 2025 or 2030 by communicating nationally determined contributions (NDCs), as well as encouraging the formulation of long-term low-emission development strategies (Article 4.19)(1). In response, many countries have either submitted or are preparing mid-century strategies(2). Most NDCs set high-level near-term goals-such as limits on emissions or emissions intensity(3)-which do not provide information about the extent to which they lay the foundations of technology, infrastructure and institutions for deeper reductions in the future, which is a key question for decision makers. Here, using a state-level model of the US embedded within a global integrated assessment model(4,5), we demonstrate that although the US NDC lieson a straight-line emissions pathway towards its mid-century strategy, the resulting energy system transitions involve non-linear transformations. The rates of capacity additions and capital investments in electricity generation beyond 2025 are more than three times the rates during the next decade. Our results demonstrate the need for global stocktaking exercises to evaluate the NDCs using metrics broader than emissions to better illuminate their effectiveness in addressing the Paris Agreement's long-term goals(6,7).