What it actually is
The Sustainable Development Goals are a set of 17 goals, and 169 underlying targets, adopted by all 193 United Nations member states in September 2015 as part of the 2030 Agenda for Sustainable Development. They are not a reporting standard, not mandatory, and have no assurance or filing mechanism attached to them. What they are is a shared global vocabulary, a way for a government, a company, an NGO, or a CSR programme to say "this is the outcome we're contributing to" in terms an international audience already recognises.
The two goals most relevant to climate-health work
Good Health and Well-Being
Ensure healthy lives and promote well-being for all at all ages, the direct home for patient access, health equity, and healthcare resilience work.
Climate Action
Take urgent action to combat climate change and its impacts, the direct home for adaptation, resilience, and emissions-reduction work.
Climate-health work almost always sits at the intersection of these two goals simultaneously, which is worth stating explicitly in a CSR report or funder proposal rather than picking just one.
How SDGs actually get used in practice
A CSR or impact report maps its programmes to specific SDGs and targets, to signal alignment with a globally recognised framework.
A funder or development finance institution requires SDG alignment as part of a grant or investment application.
A company references specific SDGs inside a GRI or BRSR report as narrative context, alongside, not instead of, the actual disclosure data.
The honest limitation: because the SDGs carry no verification mechanism, "SDG-aligned" is one of the easiest claims to make and one of the hardest to independently check. Pairing an SDG reference with an actual measured outcome, a materiality score, a BRSR metric, a GRI disclosure, is what makes the claim credible rather than decorative.
Related in the Guide: SDGs · United Nations Sustainable Development Goals (official site)
How the SDGs relate to other frameworks
Nearly every formal reporting framework, GRI, BRSR, CDP, allows or encourages a company to cross-reference its disclosures against relevant SDGs, but none of them require it. The SDGs sit above the reporting frameworks as shared vocabulary, not inside them as a requirement.