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The evolution of Earthly’s project assessment
The Keystone methodology has been going beyond carbon and beyond doubt for over five years.
How Keystone raises the bar for nature project integrity
Less than 10% of projects pass Earthly's quality assessment
Earthly's project assessment has gone through five years of meticulous iterations - each one pioneering project integrity in the market at the time. Every project on our marketplace have passed our assessment and we always have a pipeline of new projects going through the assessment process. We periodically review and reassess existing projects too. Less than 10% of projects pass Earthly's integrity assessment - this make us stand out as especially demanding, but we stand by our high standards to drive integrity in the wider market.
January 2021
Keystone
Pioneering 'beyond carbon' scoring
The first framework on the market to combine carbon, biodiversity and social outcomes for carbon and nature projects in a single assessment. In an industry dominated by carbon-only thinking, Keystone 0.0 introduced a whole-ecosystem perspective - capturing co-benefits, IPLC rights, governance risks and red flags that no other tool was looking for.
First combined framework in market
Red-flag system
Co-benefits recognition
IPLC & governance checks
June 2022
Keystone 1.0
The decision framework
As scrutiny of carbon markets intensified, Keystone 1.0 rebuilt the assessment as a rigorous due diligence tool. It introduced maturity and confidence scoring - enabling genuine comparability between projects for the first time - and aligned to IUCN standards, putting scientific evidence at the centre of every decision.
Maturity & confidence scoring
IUCN-aligned
True due diligence
Evidence & validation
September 2022
Keystone 2.0
A structured decision tool
As REDD+ controversies and over-crediting concerns dominated the market, Keystone 2.0 quickly restructured the framework for comparability at scale. A dual-axis scoring matrix - crossing maturity against confidence - replaced a binary pass/fail. Our unique 'spider-diagram' data visualisations made portfolio analysis visual and intuitive.
Dual-axis scoring matrix
Minimum pass threshold
Spider diagram data visualisation
Weighted sections
Co-benefit extraction
September 2025
Keystone 3.0
Market-ready system
Keystone 3.0 is the most comprehensive nature project assessment available. Built to meet the disclosure requirements your sustainability team is already navigating - TNFD, CSRD, ICVCM Core Carbon Principles - while going further at project level. Questions adapt to project type and geography, making it the only framework that applies rigorously across every ecosystem and registry.
TNFD-aligned
ICVCM Core Carbon Principles
CSRD-ready
FPIC & human rights
Registry-agnostic
Geography-independent
Assesses biodiversity credits
How your business can go beyond reduction
De-risk your nature and carbon strategy
Nature risk is financial risk, and you want a defensible carbon strategy.
Earthly works with 800+ responsible businesses who trust us to do the due diligence on nature and carbon projects, and to match them with solutions that fit their needs and goals. If you'd like to read more about the evolution of Keystone and it's context, we've written a blog. Additionally, in the Keystone 3.0 whitepaper, you'll find a deep-dive into the Keystone 3.0 and its methodology. Then, browse the best-in-class projects on our marketplace and get in touch with our team to talk about your organisation's priorities and requirements.
More about the assessment's evolution
Head to our blog for the full story of Keystone's evolution and the context of the nature and carbon markets along the way.
Read the blogA deep-dive into the latest version: 3.0
The Keystone 3.0 Whitepaper details what makes the latest version so special and outlines our methodology.
Access the whitepaperBrowse high-integrity nature projects
View the projects that passed; the scores we gave them; and their unique co-benefits across carbon, social and biodiversity.
Go to marketplaceSchedule a call with one of our experts