Leading the transition: WWF Spain assesses the climate transition plans of the IBEX35

Report prepared for WWF Spain by Marcio Viegas, founder and managing director of SUST4IN, in his capacity as a researcher. The report is available in Spanish only.

Key facts

• What: “Liderar la transición” (“Leading the transition”), a WWF Spain report published on 10 November 2026, during COP31.
• Author of the study: Marcio Viegas, as a researcher for WWF Spain.
• Scope: the climate transition plans of the 35 IBEX35 companies.
• Main result: an average of 81/100 for compliance with ESRS E1-1 and 67/100 for ambition and credibility, a gap of 13 points.
• Most common gap: climate targets are not backed by the investments needed to meet them.

IBEX35 companies score an average of 81 out of 100 for compliance with the European standard on climate transition plans. On ambition and credibility, however, they score 67. The average gap is 13 points and, moreover, every single company shows one.

In short, this is the main finding of “Liderar la transición: credibilidad y ambición en los planes de transición climática del IBEX35”, published today by WWF Spain on the second day of COP31 in Antalya. The report presents the results of the study that our founder, Marcio Viegas, carried out as a researcher for WWF Spain during 2026.

What was measured

Specifically, the study reviews the public disclosures of the 35 companies in Spain’s leading stock index against two yardsticks:

• Compliance with ESRS E1-1, the European disclosure requirement for climate transition plans.
• Ambition and credibility, using WWF’s AMBIC framework: 31 criteria in 8 dimensions, drawn from 14 regulatory and market frameworks. For this reason it also covers just transition, nature and the consistency of policy engagement (lobbying).

In addition, the analysis draws on in-depth interviews with ten of the companies and on the red flag methodology of the universities of Zurich and Oxford. We used AI tools with traceable evidence, because every assessment rests on verbatim quotes from the reports, and expert review.

The results

• Of the 35 companies, 34 publish a transition plan that can be assessed.
• Average compliance: 81/100. Seven companies score 90 or more, while four score below 70.
• Average ambition: 67/100. No company reaches 85, while 18 score below 70.
• Finally, 33 of the 34 companies assessed do not evaluate whether their policy engagement is aligned with the 1.5 ºC goal.

By sector, the gap is similar across the three main groups:

Where the gaps are

Overall, almost every company has climate targets. Many, however, do not explain which investments (CapEx and OpEx) will deliver them. Some financial institutions, for example, treat that information as confidential or not material. And a target without an investment plan is hard to believe.

The report also highlights other gaps:

• the lack, in some companies, of targets explicitly aligned with 1.5 ºC;
• weak management of Scope 3 emissions, which account for most of the reported footprint;
• the absence of clear fossil fuel phase-out pathways;
• the use of carbon credits to support neutrality claims, in some cases counted against reduction targets;
• gaps in the integration of nature and just transition.

Sector by sector

For banks and insurers, the climate footprint lies in the activities they finance, invest in and insure. Energy and industry must transform facilities, technologies and products, so that today’s investments do not lock in fossil fuel dependence for decades. Finally, in transport, infrastructure, telecoms and consumer goods most of the impact arises in the value chain: suppliers, products and users.

Recommendations

In light of these results, WWF addresses recommendations to five groups: companies and financial institutions, public authorities, supervisors, auditors and assurance providers, and investors. Specifically, it asks companies to align their plans with 1.5 ºC and to set absolute reduction targets backed by investment. It also asks them to phase out fossil fuels, limit carbon credits to residual emissions, and integrate nature, just transition and consistent policy engagement.

A missing metric: electrification

The report identifies electrification as one of the main decarbonisation levers. It is also easy to measure: the share of electricity in total energy consumption. Since the revised ESRS have dropped many of the quantitative metrics, banks, investors and NGOs should start asking for it. (This is SUST4IN’s view, not WWF’s.)

Frequently asked questions

Who prepared the report “Liderar la transición”?

WWF Spain publishes it, and Marcio Viegas, founder and managing director of SUST4IN, carried out the study as a researcher for WWF Spain.

Which companies does it cover?

It covers all 35 companies in the IBEX35, Spain’s leading stock index. Of these, 34 publish a transition plan that can be assessed.

What is the main conclusion?

Companies perform better on disclosure requirements (81/100) than on ambition and credibility criteria (67/100). Therefore, publishing a plan does not guarantee that it is credible.

What is ESRS E1-1?

It is the requirement of the European Sustainability Reporting Standards (ESRS) that obliges companies to disclose their climate transition plan.

What is the AMBIC framework?

It is WWF’s framework for assessing the ambition and credibility of transition plans. Its 31 criteria are grouped in 8 dimensions, including just transition, nature and policy engagement.

Is the report available in English?

No. The report is in Spanish only, while this summary is available in English and Spanish. You can download it from WWF Spain’s website: Liderar la transición (PDF, 22 pages, in Spanish).