As the biggest greenhouse gas (GHG) emitter globally, China has pledged to achieve carbon neutrality by 2060. However, the environmental sustainability of this goal has not been assessed comprehensively on a life cycle basis. Focusing on the electricity sector, which contributes >40% to China's GHG emissions, this study evaluates the role and the potential of renewables for achieving net-zero by estimating their life cycle impacts across 31 provinces in China. A future (2050) renewable electricity grid is designed considering daily demand and generation curves, as well as resource potential and future technological advancements. Most of the electricity is generated by solar and wind (70%), followed by hydro (9%), biomass with and without carbon capture and storage (6%), and energy storage (14%). This mix achieves a net-negative climate change impact of −12 kg CO 2 eq./MWh electricity generated (compared to the current 877 kg CO 2 eq./MWh). The net negative impact is found in 18 provinces (−2.1 to −166.1 kg CO 2 eq. per MWh) owing to the biomass energy with carbon capture and storage (BECCS). The rest of the provinces have a net-positive but still relatively low impact (0–42 kg CO 2 eq./MWh) because of the high share of renewables. The majority of the remaining 17 impacts are also significantly lower (5.5–96%) than the impacts of the current grid, except for metal depletion, water consumption and freshwater and marine ecotoxicity. The minimum requirements for achieving the net-zero target for the electricity sector are either the utilisation of 55% of the total estimated biomass energy potential of 22 EJ, or BECCS share of 46% in the total capacity of biomass plants, equivalent to 2.25% of electricity generation. These results help to identify the environmental trade-offs in meeting the decarbonisation targets and to guide a future deployment of net-zero electricity in China.

To accommodate population growth and shifting diets, the global protein supply must increase. Simultaneously, rising climate variability increases agricultural yield shocks, disrupting conventional crops. Worse, global catastrophes such as nuclear war or pandemics could collapse the global food system. Here, we turn to the potential of grasslands and plentiful legume biomass (e.g., alfalfa, clover) to address these challenges. We demonstrate the potential and cost of integrated biorefineries for food production from biomass to obtain leaf protein concentrate (LPC), lignocellulosic sugar, and/or single-cell protein (SCP). These sustainable alternatives to conventional protein and sugar sources show remarkable global production potential: LPC + sugar could fulfill ~5% of the caloric requirements in one year, while LPC factories alone could fulfill global protein needs within 2 years. Combining LPC and SCP production enables food protein per hectare yields higher than any conventional food crop. Our crop modeling shows that LPC from grasslands could be more than enough to cover global calorie requirements. Even in extreme nuclear winter scenarios, grasslands could meet global protein requirements. However, this would require a large effort to multiply global legume biomass production several times over. The product is affordable for global catastrophe response, at ~$1/kg (dry) of food, or a retail cost of ~$1–2/person/day to fulfill energy needs. Locations with long growing seasons, low biomass cost, and repurposable infrastructure minimize production costs. Future work should model tradeoffs with competing uses of land (food crops, grazing, etc.) to improve policy recommendations for crisis response.

Reducing carbon inequality has become a central challenge under the carbon-neutrality agenda. However, the increasing role of multinational enterprises (MNEs) in shaping regional inequality remains unclear. Using newly developed Inter-City Input–Output Tables that distinguish MNEs activities, this paper quantifies MNEs-induced carbon footprints and value added across Chinese cities, traces the interregional transfers they generate, and evaluates their effects on inter-city carbon inequality. Results show that MNEs induce substantial but spatially uneven emissions and economic gains. The counterfactual simulations indicate that MNEs significantly mitigate the escalating inter-city carbon inequality during 2002–2017. Structural decomposition analysis reveals that this equalizing effect is driven primarily by technology spillovers and cleaner supply-chain structures, whereas scale effects tend to exacerbate disparities. These findings deepen our understanding of how foreign investment shapes interregional carbon inequality and highlight the potential for strategically leveraging MNEs activity to promote greener and more regionally balanced development in large emerging economies.