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Climate regulation in the United States is moving beyond fragmented,...
Climate regulation in the United States is moving beyond fragmented, sector-specific initiatives toward structured, economy-wide accountability. While federal disclosure initiatives continue to evolve, states are increasingly acting as policy laboratories, establishing binding frameworks that redefine how environmental data is generated, governed, and scrutinized. New York’s Mandatory Greenhouse Gas Reporting Program under 6 NYCRR Part 253 is one of the most significant regulatory shifts in US emissions reporting.
Finalized in December 2025, Part 253 introduces a statewide, mandatory reporting regime that requires in-scope entities to submit complete, source-specific, and auditable.
Most organizations built their initial greenhouse gas inventories for voluntary sustainability reporting, investor questionnaires, or internal performance tracking. Data was typically extracted manually from invoices, meters, fuel logs, and procurement records, processed through spreadsheets, and reviewed by a small internal team. This approach was tolerable in a voluntary context, where methodological variation and estimation were accepted.
Part 253 fundamentally changes the technical bar. The regulation mandates source-specific categorization, application of 20-year global warming potentials, explicit treatment of upstream and downstream emissions for certain categories, formal monitoring plans, and documentation that must withstand independent verification. For entities classified as Large Emission Sources, the operating model will resemble financial reporting more closely than sustainability narrative building.
In this environment, spreadsheets may still have a role in analysis and scenario modelling. They cannot serve as the backbone of a recurring, regulator-facing reporting regime with assurance expectations. The absence of structured controls, lineage, and governance makes spreadsheet-driven inventories structurally fragile when subjected to regulatory inspection.
Understanding Part 253 readiness requires moving beyond the concept of “having an inventory” to designing an emissions data architecture that can operate under regulation. In practice, this architecture must support repeatability, auditability, and regulatory inspection. A useful way to frame this is through four interdependent layers: data capture, calculation logic, control and evidence, and reporting output. Each layer serves a distinct regulatory function and failure at any one point weakens the entire compliance posture.
At the data capture layer, organizations must connect the systems that hold emissions-relevant activity data. This typically includes fuel procurement systems, utility billing platforms, energy management systems, SCADA, logistics applications, waste tracking tools, and ERP environments. For fuel suppliers and electric power entities, this layer must also encompass customer, contract, and shipment data, since downstream and import/export emissions are calculated from commercial flows rather than internal consumption alone.
Fragmentation at this layer is one of the most common structural weaknesses. Activity data often sits across multiple business units, locations, and systems with inconsistent identifiers and formats. Under Part 253, this fragmentation directly undermines the ability to produce complete and reconciled emissions figures. A Part 253-ready architecture therefore requires deliberate integration of these operational data sources into a single, coherent data intake structure.
The calculation layer is where raw activity data is transformed into reportable greenhouse gas emissions in line with Part 253. This is not a generic conversion exercise. It requires accurate mapping of activities to NYSDEC source categories, application of 20-year global warming potentials, and differentiated treatment across facilities, fuel suppliers, electric power entities, and waste haulers.
Each category under Part 253 carries distinct methodological rules. The logic applied to a stationary combustion source is not the same as that applied to fuel distribution, electricity imports, or waste transport. This means calculation methodologies must be explicit, transparent, and consistently applied across the organisation. They must also be maintainable, as regulatory guidance evolves and clarifications are issued. Hard-coded spreadsheet formulas and undocumented assumptions are structurally incompatible with this requirement.
Above calculation sits the control and evidence layer. Part 253 explicitly expects written monitoring plans, quality assurance procedures, and records sufficient to support both regulatory review and third-party verification. In practice, this means defined data ownership, formal review workflows, version control, audit trails, and the ability to trace every reported figure back to its source data and underlying assumptions.
This is the layer that most organizations underestimate. Without structured controls, even technically accurate data becomes difficult to defend. Verifiers will test not only the numbers, but the processes used to generate them. Where data was sourced, who reviewed it, what assumptions were applied, and how changes were managed all become inspection points. If this layer is weak, verification becomes slow, intrusive, and high-risk.
The final layer is the reporting output layer. This is where controlled, calculated, and validated data is structured for submission through the New York e-GGRT system. It must align with NYSDEC’s reporting architecture while also supporting internal management reporting and potential reuse for other regimes such as EPA Part 98, SEC climate disclosures, or additional state programs.
This layer is not just about formatting. It is about ensuring that what is reported externally is fully consistent with internal records, monitoring plans, and audit trails. In a regulated environment, discrepancies between internal dashboards and regulatory submissions create unnecessary exposure. A Part 253-ready architecture ensures that reporting is a downstream reflection of a controlled system, not a last-minute compilation exercise.
As companies begin preparing for Part 253, similar weaknesses surface across sectors. These are not isolated issues. They are structural patterns that emerge when voluntary reporting systems are stress-tested against regulatory requirements.
Activity data is often scattered across business units with inconsistent identifiers, formats, and ownership. Fuel data may sit in procurement systems, electricity data in facilities or energy management tools, logistics data in transport platforms, and waste data with external vendors.
Under Part 253, this fragmentation directly undermines consolidation. Without a unified data structure, organizations struggle to reconcile totals, identify overlaps, or demonstrate completeness. What was tolerable when reporting was narrative-driven becomes a material risk when data must be source-specific, complete, and auditable.
Methodologies used for voluntary inventories frequently do not align with New York’s requirements, particularly around the application of 20-year global warming potentials and the explicit treatment of upstream and downstream emissions.
Many organizations are still operating on 100-year GWP assumptions and simplified boundary definitions. Under Part 253, these approaches are no longer acceptable. The regulation requires differentiated treatment across facilities, fuel suppliers, power entities, and waste categories. This forces a methodological redesign, not just a recalculation.
Control environments are usually underdeveloped. Many organizations lack formal review workflows, documented assumptions, change logs, and retained evidence for specific estimates.
In practice, this means emissions numbers exist without a defensible trail explaining how they were derived, who approved them, and what judgement calls were applied. Under a verification regime, these gaps translate directly into expanded sampling, remediation requests, and qualified opinions.
This is where many teams experience their first real friction with assurance providers.
Even where data exists, evidence retention is often weak. Source invoices, meter records, contracts, and calculation workings are not systematically linked to reported numbers. Files may sit in email inboxes, local drives, or unstructured folders.
When verifiers request supporting documentation, teams scramble. This increases audit effort, extends timelines, and creates unnecessary exposure. Under Part 253, traceability is not optional. It is an expectation.
Finally, many organizations discover that their spreadsheet-based models cannot scale. Manual data pulls, copy-paste workflows, and offline reviews become unmanageable when volume, frequency, and scrutiny increase. It is a structural limitation of the toolset as spreadsheets were never designed to act as regulated data infrastructure.
This is where a dedicated ESG and GHG platform becomes relevant. SAMESG® is designed to centralize emissions data into a unified, controlled environment, which aligns closely with what Part 253 demands. Its value is not in “automation” as a buzzword, but in structural alignment with regulatory architecture.
At the data capture level, SAMESG® can ingest structured inputs from ERP systems, energy management platforms, fuel billing systems, logistics applications, and waste tracking tools.
This reduces reliance on manual consolidation across teams and geographies. Instead of emissions data being assembled through email chains and spreadsheet merges, it is captured into a single controlled environment. This directly addresses the fragmentation risk that Part 253 exposes.
Within the calculation layer, SAMESG® can apply Part 253-aligned methodologies, including 20-year GWPs and category-specific rules for facilities, fuel suppliers, electric power entities, and waste haulers.
The logic is consistent across sites and business units. This matters because inconsistency is one of the most common causes of verification challenges. When two similar sources are treated differently without justification, assurance breaks down. A rules-based platform removes that variability.
The platform’s workflow, audit trail, and documentation capabilities provide the control and evidence layer that monitoring plans and verifiers expect. Roles, approvals, and change histories can be configured so that every material data point is traceable.
Supporting evidence such as meter records, invoices, contracts, and calculation workings, can be linked directly to the relevant data points. This materially reduces verification friction and allows organizations to demonstrate that their monitoring plan is not theoretical, but operational.
At the reporting layer, SAMESG® can generate structured outputs aligned to New York’s reporting architecture, while also supporting internal dashboards and reuse for other regimes.
This is not about formatting convenience. It is about ensuring that regulatory submissions are a downstream reflection of controlled data, not a last-minute reconstruction. The same dataset can be reused for SEC climate disclosures, EPA Part 98, or future state programs without rebuilding the entire process.
The strategic role of SAMESG® is as backbone infrastructure, not an overlay tool. It replaces ad hoc pipes and bespoke formulas with a repeatable, governed architecture.
Instead of rebuilding compliance logic for every regulation, organizations configure once and operate consistently. That is the difference between managing Part 253 as an administrative burden and embedding it into the core data fabric of the organization.
Although Part 253 is formally positioned as a reporting regulation, its real impact is architectural. The organizations that will be operationally stable in 2027 are not the ones that file first, but the ones that use 2026 to redesign how emissions data is captured, governed, and controlled.
A Part 253–ready GHG data stack is not about faster reporting. It is about building a system that can sustain regulatory scrutiny, verification pressure, and future policy layering. When emissions data is embedded into core data flows, supported by defined controls and auditability, compliance stops being an annual disruption and becomes a managed process. This is what reduces verification friction, limits remediation cycles, and enables credible engagement with regulators and assurance providers.
Once emissions data is flowing through a controlled architecture, its value also changes. It becomes usable for capital planning, site-level decision making, cost exposure analysis, and transition scenario modelling. This is the point at which emissions data moves from obligation to operational input.
Using platforms such as SAMESG® to centralize data capture, standardize calculation logic, and enforce governance controls can materially accelerate this shift, helping organizations move away from fragmented inventories toward a single, defensible emissions backbone. The role of technology here is not automation for convenience, but infrastructure for credibility.
New York is using Part 253 to construct the emissions backbone of its climate policy. Organizations that invest in their own data foundations now will not only meet the immediate regulatory bar, but will be structurally better positioned for the next wave of climate regulation that will inevitably build on it.
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About the author
Director – Projects & Value Chain at SAM Corporate LLC
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Rajagopal Kannan is the Director of Projects & Value Chain at SAM Corporate LLC, leading ESG, risk management, and sustainability initiatives. With over 20 years of experience, including a decade in banking and financial risk, he specializes in credit structuring, Basel II & III, ISO 31000, COSO ERM, internal audit, and regulatory compliance under CBUAE, DFSA, ADGM, and SCA.
His current focus lies in ESG integration, climate and sustainability risk management, and value chain sustainability. A GRI-certified Sustainability Professional and GARP-certified SCR holder, he also holds multiple global credentials including PRM®, GRCP, GRCA, CRCMP, CBiiiPro, CSM, and CISI Level 3.
