Sustainability leaders urge ISSB to agree to introduce dedicated nature standard

In an open letter to the International Sustainability Standards Board, signatories urge the ISSB to align with the latest science, private sector momentum and global policy commitments by choosing to introduce a standard on nature.

Read the letter below, published ahead of the ISSB Board meeting which takes place on Earth Day, 22 April.

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To: ISSB Chair, Emmanuel Faber, and Board Members

Cc: ISSB Investor Advisory Group, IFRS Sustainability Standards Advisory Forum

Monday 20 April 2026

A critical opportunity would be missed if ISSB were to ignore the latest science, private sector momentum and global policy commitments by choosing not to introduce a standard on nature.

Dear ISSB Chair and Board Members,

We, the undersigned, are extremely concerned to hear of the ISSB staff recommendation to not develop a nature standard. We respectfully request that the ISSB Board develops a nature standard that builds on, supports and closely follows TNFD’s guidance and ISSB’s existing standards by integrating nature-related disclosure.

The science is clear in stressing the imperative to integrate nature and climate actions, and on the fact that reducing emissions without also protecting natural carbon stocks and sinks will prevent the world from achieving the goal of the Paris Agreement to limit global warming to 1.5°C. For business and financial institutions, this means that without integrating nature into decision-making we cannot address the financial impacts of climate change, the subject of the ISSB’s current standards, in addition to omitting the impacts derived from nature loss and degradation. Investors require standardized and comprehensive nature disclosures from companies to enable informed capital allocation decisions. The news that ISSB would develop a nature standard was positively received by many financial institutions.

The materiality of nature is indisputable. Even if all climate targets on GHG emissions were met, the current pace of nature loss would on its own push us beyond the Paris climate limit. And nature regulates the ultimate stability and resilience of all biosphere functions that form the basis for the global economy. Extreme weather events, biodiversity loss and ecosystem collapse, and critical change to Earth systems, topped the World Economic Forum’s Global Risks Report list in 2026; the IPBES Business and Biodiversity Report found that “biodiversity losses caused by economic activity put the future of businesses, the economy and global society at risk”; and Oxford University, Global Canopy and TNFD research issued in 2025 highlighting 600 examples of financial materiality.

Nature loss directly affects food security, water availability and economic stability, and is therefore financially material, with global potential costs reaching up to $2.7 trillion per year, according to the World Bank.

Recognition of nature-related financial materiality across business and finance is accelerating, as demonstrated by the development of the ESRS E4 Standard on Biodiversity and Ecosystems by the EU, the implementation of new GRI and ISO biodiversity standards, the 750 Early Adopters of the TNFD framework, the more than 500 stakeholders engaged in the development of an aligned set of practical and credible state of nature metrics through the Nature Positive Initiative, plus the over 200 financial institution signatories of the Finance for Biodiversity Pledge, to name but a few examples.

We also note the accelerating ease of measuring nature through the standardization of metrics, and the wide availability of granular Earth observation data, species data through innovations such as eDNA and open access sharing platforms, and the ability of agentic AI to practically synthesize this data for users.

Should ISSB decide to follow its staff recommendation for a non-mandatory approach to nature, this would disregard the growing recognition across business and finance of the materiality of nature, scientific recommendations for the integration of climate and nature, and global momentum of private sector concern, action and disclosure on nature. This is in essence a regressive decision that would delay progress – and it is clearly out of sync with today’s science, financial materiality, momentum and needs.

We believe, on the other hand, that a standalone nature standard, drawing on TNFD, minimizes disruption to the ongoing adoption of ISSB S1 and S2 Standards by countries – while filling the significant gap around assessing financially material nature-related impacts and dependencies and the provision of this information to investors. We recommend that this standard is designed to aid the integration of nature into the disclosures prepared through S1 and S2. Additionally, we note that a dedicated S3 nature standard would provide a unified, international framework for countries to implement Target 15 of the Kunming-Montreal Global Biodiversity Framework, which 196 governments have committed to and which calls on government to introduce mandatory requirements for reporting on biodiversity, thus lifting significant implementation burden from many of these countries. A dedicated S3 nature standard was also recommended to the ISSB Board by the majority of the 16 regulators members of the IFRS Sustainability Standards Advisory Forum at their last meeting on 24 March 2026.

April 22 – the day that the ISSB Board will meet to discuss this matter – is also Earth Day. This is an occasion to signal the need to foster global unity for environmental protection and integration of socio-economic and environmental agendas, shifting from awareness to active stewardship of the planet. In the spirit of Earth Day, we therefore call on ISSB to agree to develop a nature standard to support and enable the private sector to assess and address their nature impacts and dependencies, in the interests of business resilience and societal health.

Sincerely,

Martin Harper | CEO, BirdLife International

Anita de Horde | Co-Founding Executive Director, Finance for Biodiversity Foundation

Marco Lambertini | Executive Chair, Nature Positive Initiative Secretariat

Dorothy Maseke | Head of Secretariat, African Natural Capital Alliance

Julie McCarthy| CEO, Nature Finance

Dame E.J. Milner-Gulland | Tasso Leventis Professor of Biodiversity, University of Oxford

Jennifer Morris |CEO, The Nature Conservancy

Carlos A. Nobre | Co-Chair, Science Panel for the Amazon

Brian O’Donnell | Director, Campaign for Nature

Paul Polman | business leader, philanthropist, investor

Johan Rockström | Director, Potsdam Institute for Climate Impact Research