Double Counting of Emission Reductions Undermines the Credibility of Corporate Mitigation Claims.

Companies are increasingly relying on emission reductions attributable to their adoption of renewable electricity to achieve net-zero emission targets. However, there is a risk of double counting of emission reductions threatening the credibility of corporate climate actions due to defective accounting rules of GHG emissions related to electricity consumption and the overlap between different market-based instruments, including carbon credit markets, renewable power purchase agreements, and renewable energy certificates. Using data of 63 major Chinese companies in seven sectors, we quantitatively assess the risks of double counting related to corporate sourcing of renewables and their consequent influences on the alignment of corporate emission trajectories with the 1.5 °C goal of the Paris Agreement. Results show that 7.1% of the electricity consumed by sample companies in 2021 was from renewable energy procurement and deployment, with which they reported 8.27 Mt of CO2e emission reductions compared to the scenario with no renewable electricity consumption. However, emission reductions that could be double counted are predicted to be 0.9-1.3 times as many as emission reductions that companies will report during 2021-2030. After adjustment of the reported emissions that might be underestimated due to double counting, the overall emission trajectories of sample companies are no longer aligned with the 1.5 °C goal. Our findings suggest that it is urgently needed to improve the corporate carbon accounting rules and increase the transparency of corporate carbon disclosures.

Climate adaptation through crop migration requires a nexus perspective for environmental sustainability in the North China Plain.

Crop migration can moderate the impacts of global warming on crop production, but its feedback on the climate and environment remains unknown. Here we develop an integrated framework to capture the climate impacts and the feedback of adaptation behaviours with the land-water-energy-carbon nexus perspective and identify opportunities to achieve the synergies between climate adaptation and environmental sustainability. We apply the framework to assess wheat and maize migration in the North China Plain and show that adaptation through wheat migration could increase crop production by ~18.5% in the 2050s, but at the cost of disproportional increment in land use (~19.2%), water use (~20.2%), energy use (~19.5%) and carbon emissions (~19.9%). Irrigation and fertilization management are critical mitigation opportunities in the framework, through which wheat migration can be optimized to reduce the climatic and environmental impacts and avoid potential carbon leakage. Our work highlights the sustainable climate adaptation to mitigate negative environmental externalities.

Environmental assessment of recycling waste corrugated cartons from online shopping of Chinese university students.

College students in China are among the main consumers of online shopping and the corrugated cartons used to ship items are piling up on campus. However, the generation characteristics of waste corrugated cartons (WCCs) in universities and the environmental consequences along their recycling pathway remain to be addressed. Taking Nanjing University (NJU) as an example, this study conducted a questionnaire survey on campus to analyze the generation characteristics of WCCs and evaluated the life cycle environmental impacts of their recycling process using the Life Cycle Assessment (LCA) method. The results showed that WCC generation on campus varied by educational level, sex, grade and major, with doctoral students and female students being more active in online shopping and thus generating more WCCs. It was further estimated that a total of 0.27 Mt of WCCs were generated by college students in China in 2020, of which recycling would result in 0.31 Mt of CO2 eq of GHG emissions. Pulping and papermaking processes are the main contributors to the life cycle environmental impacts of WCC recycling, together accounting for at least 77% of the total. This study suggests the need for joint efforts from universities, students, and recycling enterprises to reduce WCC generation in Chinese universities and to make its recycling chain more environmentally sustainable.