供应链中的深度脱碳和浅层脱碳

11306 Deep and Shallow Decarbonizationin Supply Chains Anne BeckAlvaro Pedraza Development EconomicsDevelopment Research GroupFebruary 2026 A verified reproducibility package for this paper isavailable athttp://reproducibility.worldbank.org,clickherefor direct access. Policy Research Working Paper11306 Abstract This paper examines how suppliers adjust their decarbon-ization choices when major customers obtain validatedemission-reduction targets. Using global supplier-customerlinks matched to firm-level emissions and project-level datafrom voluntary carbon registries, the analysis shows thatdownstream climate pressure elicits both real and symbolicresponses, but in systematically different ways across sup-pliers. On average, treated suppliers become more likelyto adopt climate targets of their own. High-emission sup-pliers subsequently reduce their emission intensity relativeto comparable firms, indicating meaningful operationaladjustments. Low-emission suppliers, by contrast, do not further reduce emissions; instead, they expand their useof carbon credits, sharply increasing offset intensity as alower-cost alternative to additional physical abatement.Theseoffsets disproportionately originate from low-er-rated projects, suggesting that increased demand doesnot translate into pressure for higher-quality credits. Over-all, downstream climate commitments induce a sorting indecarbonization strategies: high-emission suppliers under-take substantive reductions, while low-emission suppliersrely more heavily on market-based mechanisms to meetcustomer expectations. This paper is a product of the Development Research Group, Development Economics. It is part of a larger effort by theWorld Bank to provide open access to its research and make a contribution to development policy discussions around theworld. Policy Research Working Papers are also posted on the Web at http://www.worldbank.org/prwp. The authors maybe contacted at apedrazamorales@worldbank.org and abeck2@worldbank.org. A verified reproducibility package for thispaper is available athttp://reproducibility.worldbank.org, clickherefor direct access. The Policy Research Working Paper Series disseminates the findings of work in progress to encourage the exchange of ideas about developmentissues. An objective of the series is to get the findings out quickly, even if the presentations are less than fully polished. The papers carry thenames of the authors and should be cited accordingly. The findings, interpretations, and conclusions expressed in this paper are entirely thoseof the authors. They do not necessarily represent the views of the International Bank for Reconstruction and Development/World Bank andits affiliated organizations, or those of the Executive Directors of the World Bank or the governments they represent. Deep and Shallow Decarbonization in SupplyChains Anne Beck∗Alvaro Pedraza† JEL Codes: F18, L14, Q54, Q56.Keywords: Carbon offsetting, Supply chain, Decarbonization, Greenwashing. 1Introduction Large corporations are increasingly adopting ambitious climate commitments, includingscience-based and net-zero targets.A defining feature of these ambitious commitmentsis that firms must account not only for their own operational emissions but also for thosegenerated upstream in their supply chains.Against this background, an increasing shareof buyers now ask, or explicitly require their suppliers to disclose emissions, adopt climatepolicies, or show measurable progress toward emissions reductions. Yet it remains unclearhow suppliers respond when faced with such downstream climate pressure. In principle, suppliers can pursue a range of adjustments: investing in abatement tech-nologies, redesigning production processes, shifting energy inputs, or relying on externalmechanisms such as carbon offset markets. Suppliers may engage indeepdecarbonization—actions that materially reduce emissions—or adoptshallowresponses that improve the ap-pearance of alignment without changing core operations. These choices differ in cost, credibil-ity, and scalability, raising the central question whether downstream climate commitmentsinduce genuine decarbonization among suppliers or instead crowd in lower-cost, symbolicforms of compliance. However, despite the growing importance of supply-chain climate gov-ernance, systematic empirical evidence on this margin is still sparse. This paper provides the first large-scale empirical analysis on how suppliers adjust theirdecarbonization strategies when facing credible, externally validated climate pressure. Weemploy a staggered difference-in-differences design that exploits the discrete timing of cus-tomers’ Science Based Targets initiative (SBTi) approvals. The SBTi approval constitutes amaterial shift in expectations of upstream decarbonization, allowing us to trace how suppli-ers reoptimize across real (operational) and market-based (offset) decarbonization channelsusing a novel combination of global supply-chain