S9 Ep40: Are net zero commitments greenwash?

Sixty-three percent of large companies worldwide had made a net zero commitment by 2023, up from close to none in 2018. But if the target date is 2050, that's several corporate lifetimes away, and the planet needs emission reductions today. What actually changes in the boardroom when a pledge is signed?

Simon Dietz (LSE, CEPR) has tracked climate management practices and emissions at nearly 2,000 companies to find out. He tells Tim Phillips that the picture is not the one that either side of the debate might expect. A net zero pledge doesn't usually signify an immediate cut in emissions, but there is a clear and early shift in how companies plan for net zero that has often started before the announcement. What is left is something is harder to spot: firms making a strategic pivot, of which the public commitment is only one part.

The research behind this episode:

Dietz, Simon, and Nikolaus Hastreiter. 2026. "Corporate Net Zero Targets: Have They Achieved Anything?" CEPR Discussion Paper 21441 (gated).

To cite this episode:

Phillips, Tim, and Simon Dietz. 2026. "Are net zero commitments greenwash?" VoxTalks Economics (podcast).

About the guest

Simon Dietz is Professor of Environmental Policy at the London School of Economics and Political Science, Research Director of the Grantham Research Institute on Climate Change and the Environment, and Research Director of the LSE Transition Pathway Initiative Global Climate Transition Centre. He is a Research Fellow of the Centre for Economic Policy Research. His research spans climate change economics, corporate sustainability, decision-making under uncertainty, and climate finance.

Research cited in this episode

The Paris Agreement and the 1.5°C target. The 2015 UN Paris Agreement on Climate Change set a goal of limiting global warming to well below 2°C, with a stretch target of 1.5°C. The Intergovernmental Panel on Climate Change subsequently concluded that meeting the 1.5°C goal requires global emissions to reach net zero by around mid-century, giving corporate net zero pledges their scientific rationale.

Science Based Targets initiative, UN Race to Zero, and the Glasgow Financial Alliance for Net Zero. These are among the organisations that encouraged corporations to adopt long-term net zero commitments following the Paris Agreement, helping drive the rapid diffusion of pledges that Dietz and Hastreiter document.

Trucost and the Transition Pathway Initiative (TPI). Dietz and Hastreiter combine two emissions datasets to overcome measurement problems in this area. Trucost provides broad coverage of around 1,600 large listed firms, combining self-reported data with modelled estimates. TPI provides sector-specific, physically normalised emissions intensity data for a smaller sample of roughly 200 companies in the highest-emitting sectors; Dietz is Research Director of the TPI Global Climate Transition Centre, which is based at LSE.

Difference-in-differences with matching. To separate the effect of a net zero pledge from the fact that greener firms are more likely to make one in the first place, the authors compare firms before and after adoption against similar firms that have not yet adopted, using propensity score matching to build a comparable control group.

The Task Force on Climate-related Financial Disclosures framework. The paper groups management practices into four pillars from this framework: governance, strategy, risk management, and metrics and targets. It finds no significant effect of net zero pledges on governance, risk management, or metrics and targets, but a significant and positive effect on strategy, including climate scenario planning and internal carbon pricing.

More VoxTalks Economics episodes

A big push for climate policy, in which Rick van der Ploeg argues that gradual policy change risks backsliding, and sets out what a genuinely transformative climate push would require.

Related reading on VoxEU.org

Corporate net zero targets: Neither greenwashing nor a gamechanger, in which Dietz and Hastreiter set out the findings behind this episode in their own words.

Corporate climate commitments: A profit-driven strategy, not just empty promises, in which Viral Acharya, Robert Engle, and Olivier Wang model when large firms and their investors have a financial incentive to follow through on climate pledges.

Business as usual: Bank net zero commitments, lending, and engagement, in which Parinitha Sastry, Emil Verner, and David Marques-Ibanez find that banks' net zero pledges predict decarbonisation of their loan portfolios, but not reduced lending to high-carbon sectors.