greenhouse gas
Enable an AI agent to recognise a greenhouse gas, assess its physical and atmospheric state, and determine appropriate measurement, handling and climate-related actions.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to recognise a greenhouse gas, assess its physical and atmospheric state, and determine appropriate measurement, handling and climate-related actions.
A greenhouse gas is a gaseous atmospheric constituent that is largely transparent to incoming solar shortwave radiation but absorbs and re-emits terrestrial infrared radiation, reducing the efficiency of Earth's longwave cooling and thereby contributing to radiative forcing of climate.
It can be Identify a gas or resolve the greenhouse-active constituents of a mixture.; Select a suitable detection method and assess whether observations support the claimed abundance.; Estimate a bounded quantity or atmospheric release from explicitly supported measurements.; Compare climate implications using a documented metric and time horizon.; Evaluate containment, recovery, reuse or treatment options against gas-specific properties and operating conditions.; Trace transformation products and verify whether an intervention actually reduced atmospheric release..
Distinguishing features
Require evidence of absorption and emission within terrestrial infrared wavelengths; being present in the atmosphere does not by itself establish greenhouse-gas status.
Distinguish a gaseous constituent from suspended solid particles or liquid droplets; condensed water and water vapour require different representations.
Distinguish a directly infrared-active gas from a precursor that affects climate only by changing the abundance of other atmospheric constituents.
Distinguish chemical identity from CO2-equivalent quantity, which is a calculated comparison using a specified metric rather than a substance.
Distinguish physical greenhouse-gas classification from inclusion in a particular reporting scheme; a reporting list is not the physical definition.
Scope
+ Chemical identity and evidence supporting classification as a greenhouse gas.
+ Specific occurrences in atmospheric air, process streams or containment, including mixtures and phase conditions.
+ Concentration, quantity and measurement uncertainty within an explicit sampling boundary.
+ Infrared activity, atmospheric transformations, removal processes and climate metrics with their applicable context.
+ Gas-specific constraints on detection, containment, recovery, treatment and release prevention.
- Whole-atmosphere climate dynamics, temperature projections and feedback-system models.
- Facility operations, equipment maintenance and emission-generating activities as independent models.
- Organisational emissions inventories, reporting boundaries and carbon-credit accounting.
- Complete lifecycle models of fuels, refrigerants, agricultural products and substitute materials.
- Aerosols, clouds and substances whose climate influence is exclusively indirect.
Characteristics
- Chemical identity
- Chemical name, formula and verified identifier; resolved species or unresolved mixture constituent. Prevents trade names, gas families and mixtures from being treated as single substances with interchangeable properties.
- Occurrence and physical phase
- Atmospheric constituent, process-stream constituent or contained inventory; gas, liquid, solid or multiphase at stated conditions. Separates the greenhouse-gas identity from the actual phase and setting of a particular quantity.
- Temperature and pressure
- K and Pa, with measurement location and time. Supports phase interpretation, sampling validity and conversions between volume and amount.
- Infrared spectral activity
- Absorption cross-section in m² per molecule as a function of wavelength or wavenumber, with temperature, pressure and source. Provides physical evidence for greenhouse activity and informs gas-specific optical detection.
- Gas abundance
- mol/mol, ppm or ppb with wet-air or dry-air basis; alternatively kg/m³ at stated conditions. Makes concentration observations comparable without confusing mole fraction, mass concentration and moisture corrections.
- Quantity within a boundary
- kg or mol within a specified vessel, stream segment or atmospheric volume at a stated time. Distinguishes an inventory from concentration and from an emission rate.
- Atmospheric persistence
- Time units with the lifetime definition and applicable conditions, or a sourced time-dependent response where one lifetime is inadequate. Supports interpretation of how long an atmospheric perturbation persists without forcing every gas into a single decay constant.
- Atmospheric sinks and transformations
- Links to chemical reactions, photochemical pathways, exchanges with reservoirs and resulting substances. Identifies where the gas goes and whether removal produces other greenhouse gases or hazardous products.
- Climate comparison metric
- Named metric and value, such as dimensionless GWP, with time horizon, reference gas, assessment version and conventions. Prevents a climate comparison factor from being treated as an intrinsic, context-free property.
- Handling hazard classification
- Sourced toxicity, flammability, oxidising, asphyxiation and pressure-related classifications applicable to the occurrence. Keeps immediate handling decisions grounded in physical hazards as well as climate effects.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Identity and greenhouse qualification Establishes which substance is represented and why it qualifies physically as a greenhouse gas.
An agent must distinguish a greenhouse-active chemical species from a mixture label, reporting category or indirectly warming substance.
Chemical resolution
Resolves names and composition to the chemical identity relevant to observation and action.
Species and mixture boundary
Record whether the subject is an identified species or a constituent of a mixture, retaining unresolved composition explicitly.
- Which chemical species does this name identify, and does it instead denote a family or commercial mixture? definition
- What analytical result or authoritative substance record supports that identity and any stated mixture fractions? provenance
Infrared qualification
Connects greenhouse classification to terrestrial infrared absorption and emission.
Direct radiative activity
Record evidence of relevant infrared activity and distinguish it from indirect atmospheric effects or administrative inclusion.
- What measured or evaluated spectrum establishes absorption and emission at terrestrial infrared wavelengths? provenance
- Does the proposed classification describe direct greenhouse activity, an indirect precursor effect or only membership in a reporting list? boundary
Physical occurrence and abundance Describes where the gas occurs, its actual phase and how much is present.
Atmospheric mole fraction, compressed inventory and liquefied storage require different interpretations even when they concern the same substance.
Phase and setting
Places the substance in atmospheric, process or containment conditions.
Occurrence boundary
Record the physical boundary, phase distribution, temperature and pressure of the occurrence being assessed.
- Is the subject an atmospheric constituent, a process-stream constituent or a contained inventory, and what physical boundary encloses it? boundary
- At the observed temperature and pressure, what fraction is gaseous and what fraction is condensed or dissolved? measurement
Abundance and detection
Makes concentration and quantity observations interpretable and comparable.
Qualified abundance observation
Record the measured quantity, sampling basis, calibration, detection limits and uncertainty without conflating abundance with emission rate.
- What concentration or bounded quantity was measured, when and where, using which units and wet-air or dry-air basis? measurement
- Which calibration, detection limit and cross-sensitivity evidence supports distinguishing this gas from other constituents in the sample? provenance
Atmospheric fate and persistence Describes entry into the atmosphere, transport context, transformations and removal.
The consequences of a release depend on atmospheric pathways and persistence, which cannot be inferred from greenhouse classification alone.
Release and formation pathways
Distinguishes direct release, atmospheric formation and transfers between reservoirs.
Atmospheric entry
Record whether the observed gas was emitted directly, formed through atmospheric chemistry or exchanged with another reservoir.
- Which direct release, chemical formation or reservoir-exchange pathways could account for this atmospheric occurrence? definition
- What evidence supports attribution to a particular pathway rather than merely detecting elevated concentration? provenance
Sinks and response
Represents removal mechanisms and the time evolution of an atmospheric perturbation.
Persistence representation
Record supported sinks and an appropriate lifetime or response function, including dependencies and consequential products.
- Which chemical reactions or reservoir exchanges remove the gas, and what substances or stored forms result? definition
- What lifetime definition or time-dependent response is supported, and under which atmospheric conditions does it apply? measurement
Radiative effect and climate comparison Connects gas abundance and release to appropriately qualified radiative and climate comparisons.
An agent must avoid treating spectral activity, atmospheric forcing and CO2-equivalent emissions as interchangeable quantities.
Radiative context
Identifies the atmospheric context required to interpret the gas's radiative contribution.
Conditional radiative effect
Record the basis of a radiative-effect estimate, including the reference atmosphere and relevant spectral interactions.
- Which abundance change, atmospheric profile and reference state does the radiative-effect estimate describe? boundary
- How does the cited method account for spectral overlap, background abundance and any included atmospheric adjustments? provenance
Metric-qualified comparison
Constrains comparisons between releases of different greenhouse gases.
Traceable climate metric
Record the metric definition, assessment source and conventions before calculating or comparing CO2-equivalent quantities.
- Which metric, time horizon, reference gas and assessment version supply the comparison factor, and is a factor available for this species? provenance
- Does the proposed comparison concern an emission pulse, a sustained emission rate or an atmospheric stock, and is the chosen metric appropriate to that decision? action
Containment, treatment and verification Supports gas-specific decisions about preventing release and managing recovered material.
Climate relevance alone does not determine whether a gas can be safely contained, recovered, reused or transformed under actual operating conditions.
Handling and recovery
Relates immediate hazards and physical properties to feasible handling interventions.
Feasible release prevention
Record hazards, material compatibility and separation constraints that determine feasible containment or recovery.
- Which toxicity, flammability, oxidising, oxygen-displacement or pressure hazards apply at the actual concentration and conditions? boundary
- Which containment or recovery methods are supported for this gas, mixture composition, pressure and flow, and what evidence establishes compatibility? action
Treatment outcomes
Tracks the gas and consequential products through reuse, conversion or storage.
Verified gas disposition
Record the fate of treated or recovered gas, residual releases and resulting substances before asserting an intervention succeeded.
- Does the intervention recover, transform or store the gas, and what residual gas, greenhouse-active products or hazardous by-products remain? action
- What inlet, outlet and retained-inventory measurements support the claimed outcome, including leakage and possible later release? measurement
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Carbon dioxide (CO2), the reference well-mixed gas for inventory accounting (GWP = 1) and the largest anthropogenic contributor to long-term warming
- Methane (CH4), a well-mixed gas with an atmospheric lifetime of about a decade and a 100-year GWP of about 27-30
- Nitrous oxide (N2O), a long-lived well-mixed gas (lifetime ~100 years) with a 100-year GWP of about 273 in IPCC AR6
- Water vapour, the most abundant greenhouse gas and the largest contributor to the natural greenhouse effect, treated in assessments as a climate feedback rather than a UNFCCC inventory gas
- Ozone (O3), a short-lived greenhouse gas in the troposphere; stratospheric ozone depletion has a small cooling effect
- Hydrofluorocarbons (HFCs), industrial fluorinated substitutes for ozone-depleting refrigerants, controlled for climate under the Kigali Amendment
- Fully fluorinated high-GWP industrial gases: perfluorocarbons (PFCs), sulphur hexafluoride (SF6) and nitrogen trifluoride (NF3)
- Montreal Protocol ozone-depleting halocarbons that are also greenhouse gases (CFCs, HCFCs, halons), listed outside Kyoto Annex A because they are controlled elsewhere
- Which of these kinds and varieties hold for the sense of greenhouse gas this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- IUPAC Gold Book - 14724 - Term 'greenhouse gases' in the Compendium of Chemical Terminology (DOI 10.1351/goldbook.14724).
- Kyoto Protocol / UNFCCC inventory gas list - CO2 | CH4 | N2O | HFCs | PFCs | SF6 [| NF3] - Annex A named six gases/classes; NF3 is the seventh gas in later UNFCCC and EU statistical practice (Doha Amendment / Eurostat).
- Chemical formula (named well-mixed species) - CO2, CH4, N2O, SF6, NF3, CF4 and HFC/PFC isomer formulae (e.g. HFC-134a as CH2FCF3) - Identifies individual gases, not the class. HFC and PFC inventories are reported as classes of isomers.
- Which of these identifiers and schemes hold for the sense of greenhouse gas this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- United Nations Framework Convention on Climate Change (UNFCCC, 1992) - national GHG inventories, communications and, under the Paris Agreement, nationally determined contributions and the enhanced transparency framework
- Kyoto Protocol (UNFCCC, 1997), Annex A - original six inventory gases and source categories; Doha Amendment added NF3 as a seventh gas
- Paris Agreement (UNFCCC, 2015) - Parties report using IPCC 2006 Guidelines and, for CO2e, 100-year GWPs from IPCC AR5
- IPCC 2006 Guidelines for National Greenhouse Gas Inventories and 2019 Refinement - methodological standard for national inventories
- ISO 14064-1:2018 (International Organization for Standardization) - organization-level quantification, reporting and verification of GHG emissions and removals
- Montreal Protocol on Substances that Deplete the Ozone Layer, including the Kigali Amendment - CFCs/HCFCs as ODS that are also GHGs; HFCs controlled for climate
- U.S. EPA 40 CFR Part 98 Mandatory Greenhouse Gas Reporting - facility- and supplier-level mass and CO2e reporting
- EU F-gas Regulation and EU/Eurostat GHG accounts - fluorinated gases and the seven-gas Kyoto basket used in European statistics
- Which of these standards and regulation hold for the sense of greenhouse gas this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- National GHG inventories submitted to the UNFCCC secretariat (CRF-style tables by gas and IPCC sector: energy, IPPU, agriculture, LULUCF, waste)
- Corporate and product carbon accounting (ISO 14064, GHG Protocol scopes), expressed as tonnes CO2e
- Facility-level compliance reporting, e.g. U.S. GHGRP covering thousands of emitters and suppliers of fuels and industrial gases
- Atmospheric monitoring networks that track well-mixed mole fractions (CO2 in ppm, CH4 and N2O in ppb, F-gases in ppt) used by IPCC assessments
- Policy instruments that trade or cap CO2e: emissions trading, NDCs, carbon taxes, and refrigerant phase-downs
- Climate-model forcing: prescribed concentrations or emissions of well-mixed GHGs versus chemically produced ozone
- Industrial uses that emit high-GWP gases: HFC refrigeration and air-conditioning, SF6 in electrical switchgear, PFCs/NF3 in electronics and aluminium
- Which of these real-world use hold for the sense of greenhouse gas this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Atmospheric CO2 mole fraction - pre-industrial ~278-280; about 410 in 2019; rising ~2.3 ppm yr−1 in recent U.S. inventory years - ppm
- Atmospheric CH4 mole fraction - pre-industrial ~700-730; about 1866 in 2019 (IPCC AR6) to ~1879 ppb in U.S. inventory tabulations - ppb
- Atmospheric N2O mole fraction - pre-industrial ~270; about 333 in recent inventory years - ppb
- 100-year global warming potential (GWP-100) - 1 (CO2); CH4 21 (SAR) / 28 (AR5) / 27-30 (AR6); N2O 310 (SAR) / 265 (AR5) / 273 (AR6); SF6 order 23,900 (SAR) and other F-gases from hundreds to tens of thousands - dimensionless (relative to CO2)
- Atmospheric lifetime - CH4 ~12 years; N2O ~109-120 years; SF6 ~1,000-3,200 years; CF4 ~50,000 years; CO2 perturbation is multi-timescale (not a single e-folding lifetime) - years
- Effective radiative forcing since 1750 - CO2 about 2.16 W m−2 in 2019; CH4 about 0.48 W m−2 in IPCC tables through AR5/AR6 concentration years; combined long-lived GHGs historically ~2.6 W m−2 (AR4-era) - W m−2
- Anthropogenic emissions as CO2 equivalent - global total of order 50 Gt CO2e yr−1 in the late 2010s; mid-2010s mix about 74% CO2, 17% CH4, 6% N2O, ~2% F-gases - Gt CO2e yr−1
- Which of these typical measurements hold for the sense of greenhouse gas this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Accumulation of long-lived GHGs produces committed surface warming: IPCC AR6 attributes about 1.4 °C (0.9-2.2 °C, 90% CI) to CO2+CH4+N2O, versus about 1.1 °C net human warming after cooling aerosols
- High-GWP leaks from refrigeration, SF6-insulated switchgear and semiconductor process gases deliver large CO2e from small mass losses
- GWP time-horizon choice (20 versus 100 years) re-ranks methane relative to CO2 and can mis-specify short-term mitigation
- N2O is both a greenhouse gas and a stratospheric ozone-depleting substance, so agricultural nitrogen surplus has a dual hazard
- Tropospheric ozone is a greenhouse gas that also injures human respiration and crop productivity
- Water-vapour feedback amplifies warming from other GHGs because warmer air holds more moisture
- Incomplete F-gas coverage in some NDCs and inventories understates industrial warming
- Land-use CO2 and biogenic versus fossil carbon accounting errors (omitted sinks, double-counted biomass) distort national totals
- Which of these failure modes and hazards hold for the sense of greenhouse gas this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Inventory CO2e depends on which IPCC GWP table is required: Kyoto/SAR (CH4 = 21), current UNFCCC/Paris reporting with AR5 (CH4 = 28, N2O = 265), versus AR6 science values (CH4 ≈ 27-30, N2O = 273)
- Original Kyoto Annex A has six gases; EU/Eurostat and later UNFCCC practice use seven by adding NF3
- Water vapour and ozone enter physical climate energy-budget accounting but are not UNFCCC national-inventory gases in the Kyoto basket
- CFCs and HCFCs are regulated as ozone-depleting substances under the Montreal Protocol, not as Kyoto Annex A gases, despite large GWPs
- National emission mixes differ: energy CO2 dominates in large industrial emitters; agriculture, waste methane and land-use CO2 are larger shares in some tropical and agrarian economies
- Policy language often says 'carbon' for all GHGs as CO2e, which is not the same as CO2 the molecule
- Which of these regional variation hold for the sense of greenhouse gas this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Atmospheric aerosol (sulfate, black carbon, mineral dust, nitrate) - Aerosols are condensed particles that mainly scatter or absorb solar (shortwave) radiation; greenhouse gases are infrared-active molecules. Test: phase (particle versus gas) and whether the forcing is shortwave scattering/absorption versus longwave absorption.
- Ozone-depleting substance (ODS) - ODS are ranked by ozone depletion potential (ODP relative to CFC-11); GHGs are ranked by infrared absorption and GWP. Intersection is real (CFCs, HCFCs, N2O) but HFCs are GHGs with negligible ODP. Test: ODP versus GWP, and Montreal versus UNFCCC gas lists.
- GHG precursor (CO, NOx, NMVOCs) - Precursors are not themselves well-mixed greenhouse gases; they chemically produce tropospheric ozone (which is a GHG). Test: whether the emitted species has a direct, inventory-relevant infrared forcing and a well-mixed lifetime, or only an indirect chemical pathway.
- Major dry-air gases (N2, O2, Ar) - Together they are ~99.9% of dry air but are essentially transparent to terrestrial infrared (homonuclear diatomics lack a changing dipole; Ar is monatomic). Test: infrared absorption spectrum in the terrestrial window.
- Carbon dioxide equivalent (CO2e) - CO2e is a GWP-weighted accounting unit, not a chemical species. Test: whether a reported figure is a measured mole fraction of one gas or a sum of masses each multiplied by a GWP.
- Near-term climate forcer / short-lived climate pollutant - That grouping is by the timescale of climate response (mainly within a decade) and includes methane and tropospheric ozone plus aerosols; it is not coextensive with 'greenhouse gas'. Test: mixing time and lifetime versus whether the species absorbs terrestrial infrared.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of greenhouse gas this model covers, and on what evidence? provenance
Sources
- greenhouse gases - Specialist chemical definition: gases relatively transparent to incoming sunlight that absorb infrared radiation from Earth's surface; named species including water vapour, CO2, methane, N2O, CFCs and tropospheric ozone.
- Kyoto Protocol, Annex A (as reproduced in FCCC/TP/2000/2) - The six UNFCCC/Kyoto inventory gases: CO2, CH4, N2O, HFCs, PFCs and SF6, plus the source-sector taxonomy used in national inventories.
- Glossary: Greenhouse gas (GHG) - Current European statistical practice covering seven Kyoto gases, including NF3 added after the original Annex A list, and conversion to CO2 equivalents.
- Understanding Global Warming Potentials - GWP definition (energy absorbed relative to 1 t CO2 over a chosen horizon, usually 100 years); AR6-range GWP-100 for CH4 (27-30) and N2O (273); high-GWP class (CFCs, HFCs, HCFCs, PFCs, SF6, NF3); UNFCCC inventory use of AR5 GWPs.
- Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020, Chapter 1 Introduction - Physical mechanism (N2 and O2 are IR-transparent); natural versus industrial GHGs; concentration, trend and lifetime table for CO2, CH4, N2O, SF6 and CF4.
- Global Greenhouse Gas Overview - Anthropogenic sources of CO2, CH4, N2O and F-gases; water vapour as a feedback; 2019 sector shares (electricity and heat 34%, industry 24%); AFOLU about 21% of global CO2e.
- Glossary - Global Warming of 1.5 °C - IPCC usage of GHG, anthropogenic emissions, CO2 as the principal anthropogenic greenhouse gas and GWP reference (GWP = 1).
- ISO 14064-1:2018 Greenhouse gases - Part 1: Specification with guidance at the organization level for quantification and reporting of greenhouse gas emissions and removals - Organization-level inventory standard; reporting in CO2 equivalent using GWPs; programme-neutral quantification and verification.
- 40 CFR Part 98 - Mandatory Greenhouse Gas Reporting - U.S. facility and supplier reporting: mass of each gas converted to metric tons CO2e with tabulated GWPs.
- National contributions to climate change due to historical emissions of carbon dioxide, methane, and nitrous oxide since 1850 - IPCC AR6 attribution: CO2, CH4 and N2O caused about 1.4 °C GMST rise (0.9-2.2 °C, 90% CI) versus about 1.1 °C net human warming after aerosols; UNFCCC/NDC coverage of the three gases versus F-gases.
What the second pass must settle
- Does an existing Vercy world model already own greenhouse-gas identity or atmospheric constituents, requiring this registry entry to link to it?
- Should the registered thing own individual gas occurrences as well as the greenhouse-gas class, or should occurrences be represented through neighbouring material models?
- Which authoritative spectral, atmospheric-fate and climate-assessment sources should govern species qualification and versioned metric values?
- How should the model represent water vapour and short-lived, spatially variable gases when a single lifetime or emission-comparison factor does not adequately support the decision?
- Where should ownership sit for dissolved or condensed inventories that can become atmospheric greenhouse gases, and what evidence is required to connect those inventories to a potential release?