DodecaGreen The Green Chemistry Portal

Global Warming Potential calculator.

Estimate the climate burden of any lab reaction from upstream material carbon intensities, direct greenhouse gas emissions, and energy use — expressed as kg CO₂e per kg of product. Uses IPCC AR6 GWP100 factors. Results update live as you type and every session stays in your browser, never on a server.

Principle 6 guide
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What is Global Warming Potential — and why does it matter?

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Global Warming Potential (GWP) is a measure of how much heat a greenhouse gas (GHG) traps in the Earth's atmosphere over a defined time horizon — typically 100 years (GWP100) — relative to the same mass of carbon dioxide (CO₂). When applied to a chemical process, GWP quantifies the total climate-change burden in kg CO₂ equivalents (CO₂e) per kg of product, accounting for upstream material production, gases emitted directly by the reaction, and the carbon cost of energy consumed.

GoalMinimise the total GWP burden per unit of product by choosing low-carbon feedstocks, eliminating or capturing high-GWP emissions, and reducing energy use — especially from fossil-fuel grids.
WhyDifferent greenhouse gases have vastly different warming effects: 1 kg of N₂O has the same climate impact as 273 kg of CO₂. Tracking GWP forces chemists to account for all GHG pathways — not just CO₂ — and supports institutional net-zero commitments.
HowSubstitute high-GWP solvents and reagents (e.g. HFCs, SF₆) for lower-impact alternatives, prevent or capture reactive GHG by-products (N₂O, CH₄), switch to low-carbon or renewable energy, and improve atom economy to reduce total material throughput.

The formula

$$\text{GWP} = \frac{\displaystyle\sum_i \frac{m_{\text{mat},i}\,[\text{g}]}{1000}\,c_i + \displaystyle\sum_j \frac{m_{\text{gas},j}\,[\text{g}]}{1000}\,\text{GWP100}_j + E\,[\text{kWh}]\cdot\text{EF}_{\text{grid}}}{m_{\text{product}}\,[\text{kg}]}$$
SymbolTermUnits
\(m_{\text{mat},i}\)Mass of each input material consumedg
\(c_i\)Upstream carbon intensity of that material (from ecoinvent or literature)kg CO₂e / kg
\(m_{\text{gas},j}\)Mass of each greenhouse gas directly emitted by the reactiong
\(\text{GWP100}_j\)100-year GWP factor for that gas (IPCC AR6, 2021)kg CO₂e / kg gas
\(E\)Total electrical energy consumedkWh
\(\text{EF}_{\text{grid}}\)Grid emission factor (UK 2023 ≈ 0.233)kg CO₂e / kWh
\(m_{\text{product}}\)Mass of desired product isolated (g ÷ 1000)kg

IPCC AR6 GWP100 factors for common gases

Greenhouse gasFormulaGWP100 (AR6, 2021)Context in chemistry
Carbon dioxideCO₂1 (reference)Combustion, decarboxylation, fermentation, acid–base reactions
Methane (fossil)CH₄29.8Solvent evaporation (natural gas), incomplete combustion
Methane (biogenic)CH₄27.9Fermentation, anaerobic processes, biogas
Nitrous oxideN₂O273HNO₃ oxidations, adipic acid synthesis, denitrification
HFC-134a (R-134a)CH₂FCF₃1,530Cryogenic coolant, aerosol propellant
HFC-32 (R-32)CH₂F₂771Refrigerant blends
HFC-23CHF₃14,600By-product of HCFC-22 manufacture
Sulfur hexafluorideSF₆25,200Electrical insulation, some plasma processes
Nitrogen trifluorideNF₃17,400Semiconductor / thin-film manufacture

Source: IPCC Sixth Assessment Report (AR6), Working Group I, Table 7.SM.7, 2021. GWP100 values for a 100-year time horizon.

Typical GWP by process type

Process / Product typeTypical GWP (kg CO₂e / kg product)Rating
Bio-based bulk chemicals (e.g. bioethanol, lactic acid)< 2Excellent
Enzymatic / biocatalytic lab synthesis1 – 5Excellent
Green lab synthesis (ambient, catalytic, minimal solvent)5 – 15Good
Optimised pharmaceutical intermediates15 – 50Moderate
Typical multi-step fine chemical synthesis50 – 200Poor
Complex APIs / reactions with high-GWP by-products> 200Poor

Indicative upstream GWP intensities (kg CO₂e/kg): ethanol ≈ 1.5 · EtOAc ≈ 2.3 · DCM ≈ 1.4 · THF ≈ 3.5 · toluene ≈ 1.0 · acetone ≈ 2.7 · water ≈ 0.001 · glucose ≈ 0.9 · acetic anhydride ≈ 1.5 · NaOH ≈ 1.1. UK grid 2023 ≈ 0.233 kg CO₂e/kWh.

Strengths and limitations

Strengths

  • Accounts for all greenhouse gases using a single CO₂e currency — not just CO₂
  • Exposes high-GWP solvents and reagents (HFCs, SF₆, N₂O) that mass-based metrics miss entirely
  • Directly links reaction design to institutional climate targets and net-zero commitments
  • Covers three distinct emission pathways: upstream materials, direct process emissions, and energy
  • GWP100 factors are internationally standardised (IPCC AR6) enabling peer comparison
  • Can be estimated at the design stage using literature data, before any experiment is run

Limitations

  • Upstream GWP intensity values vary by supplier, country of production, and database (ecoinvent, GaBi)
  • Direct GHG emissions from lab reactions are rarely measured; estimates are often uncertain
  • Does not capture toxicity, water use, land use, ozone depletion, or other impact categories
  • GWP100 assumes a 100-year horizon; GWP20 values are much higher for short-lived gases (CH₄)
  • This tool covers a simplified process boundary — not a full cradle-to-gate or cradle-to-grave LCA
  • Biogenic CO₂ accounting is complex: fermentation CO₂ may be climate-neutral under some frameworks

GWP in context: complementary green metrics

MetricWhat it measuresCaptures GHG climate impact?
GWP (this tool)Total greenhouse gas burden per kg product (kg CO₂e/kg) — all three pathwaysYes — primary purpose
Atom Economy (AE)Theoretical fraction of reactant mass incorporated into desired productNo
E-factorMass of all waste per mass of product (includes solvents, excess reagents)No (unless energy waste included)
PMI (Process Mass Intensity)Total mass input per mass of productNo
RME (Reaction Mass Efficiency)Combined practical mass efficiency: AE × yield × stoichiometryNo
% YieldFraction of theoretical product actually isolatedNo
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Experiment details

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Input materials

Enter every consumed material — reagents, solvents, catalysts, and workup chemicals. For each, enter the actual mass used in grams and the upstream GWP intensity (kg CO₂e per kg of that material) from ecoinvent, literature, or supplier environmental data. Do not include the product here.

Reference upstream GWP intensities (kg CO₂e/kg): glucose ≈ 0.9 · yeast ≈ 2.0 · acetic anhydride ≈ 1.5 · acetic acid ≈ 0.9 · EtOAc ≈ 2.3 · EtOH ≈ 1.5 · DCM ≈ 1.4 · THF ≈ 3.5 · acetone ≈ 2.7 · toluene ≈ 1.0 · H₂O ≈ 0.001 · NaOH ≈ 1.1 · H₂SO₄ ≈ 0.15
Material name Category Mass used (g) Upstream GWP (kg CO₂e/kg) CO₂e (kg)
Σ Upstream material emissions kg CO₂e Scope 3 upstream contribution
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Direct greenhouse gas emissions

Enter any greenhouse gases directly emitted by the reaction itself — for example CO₂ from a decarboxylation, N₂O from an HNO₃ oxidation, CH₄ from an anaerobic process, or refrigerant losses. Select the gas type and the GWP100 factor (IPCC AR6) fills automatically. Use Custom for unlisted gases and enter the factor manually.

Key GWP100 factors (IPCC AR6, 2021): CO₂ = 1 · CH₄ (fossil) = 29.8 · CH₄ (biogenic) = 27.9 · N₂O = 273 · HFC-134a = 1,530 · HFC-32 = 771 · HFC-23 = 14,600 · SF₆ = 25,200 · NF₃ = 17,400
Gas Mass emitted (g) GWP100 factor CO₂e (kg)
Σ Direct GHG emissions kg CO₂e Scope 1 direct process contribution
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Energy use & product output

Enter the total electrical energy consumed by all equipment during the reaction (hotplate, stirrer, pump, condenser, etc.). Use a plug-in energy meter for accuracy, or estimate from rated power × time. Then record the product name and the mass actually isolated.

Estimate: rated power (W) × time (h) ÷ 1000
UK 2023 ≈ 0.233 · EU avg ≈ 0.276 · US avg ≈ 0.386
Energy emissions: kg CO₂e Scope 2 energy contribution Product mass: g
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Results

Process GWP
kg CO₂e / kg product
Total CO₂e
kg CO₂e
Materials + Direct
kg CO₂e
Energy emissions
kg CO₂e
GWP scale (lower is better)
0255075≥ 100 kg CO₂e/kg

Emissions by source

Materials & direct vs. energy emissions

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Detailed breakdown & interpretation

Material / Gas / Source Pathway Quantity GWP factor CO₂e (kg) % of total Visual
Enter input materials, direct GHG emissions, energy use, and product mass above to see the breakdown.

Interpretation

Enter your inputs and product mass above to generate an interpretation.
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Save & load sessions

Sessions are stored in your browser only. No data leaves your device.

No saved sessions yet.
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Export

Export your GWP calculation as a PDF report or CSV data file. PDF opens in a new tab and uses your browser's print function. CSV downloads directly. Charts can be exported as SVG vector files.

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Where can I read more?

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References are sorted alphabetically by first author.

  1. P. T. Anastas and J. C. Warner, Green Chemistry: Theory and Practice, Oxford University Press, 1998. ISBN 978-0-19-850698-0. — Original statement of the 12 Principles; frames energy efficiency as Principle 6.
  2. A. D. Curzons, D. J. C. Constable, D. N. Mortimer and V. L. Cunningham, "So you think your process is green, how do you know? — Using principles of sustainability to determine what is green," Green Chem., 2001, 3, 1–6. DOI. — Contextualises mass- and energy-based metrics in green chemistry assessment.
  3. DESNZ/BEIS, UK Government GHG Conversion Factors for Company Reporting, 2023. — Source for UK grid emission factor: 0.233 kg CO₂e/kWh.
  4. ecoinvent Centre, ecoinvent database v3.9, 2022. — Source for upstream GWP intensity data for common reagents and solvents.
  5. IPCC, "Climate Change 2021: The Physical Science Basis," Sixth Assessment Report (AR6), Working Group I, Table 7.SM.7, Cambridge University Press, 2021. — GWP100 reference values used in this tool.
  6. C. Jiménez-González, C. S. Ponder, Q. B. Broxterman and J. B. Manley, "Using the Right Green Yardstick: Why Process Mass Intensity Is Used in the Pharmaceutical Industry to Drive More Sustainable Processes," Org. Process Res. Dev., 2011, 15, 912–917. DOI. — PMI and mass efficiency in context alongside carbon metrics.
  7. E. Lucas, A. J. Martín, S. Mitchell, A. Nabera, L. F. Santos, J. Pérez-Ramírez and G. Guillén-Gosálbez, "Integration of mass- and energy-based metrics with life cycle impacts for the assessment of chemical processes," Green Chem., 2024, 26, 9300–9309. DOI. — Demonstrates combining GWP with mass-efficiency metrics.
  8. P. Patel, D. Sherwood, S. Sherwood and A. Sherwood, "Reducing the carbon footprint of pharmaceutical manufacturing," Green Chem., 2023, 25, 4908–4917. DOI. — Practical strategies for GWP reduction in pharmaceutical synthesis.
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Contributors

Roles follow the CRediT taxonomy (Contributor Roles Taxonomy), adapted for educational software. Hover a contributor's name for a summary, or a column header for the definition of that role.

Contributor

© 2024– DodecaGreen Project. All rights reserved. · Last updated: 05/06/2026

This portal was built with the assistance of a large language model (Claude, Anthropic), which was used to generate and refine code, articulate and structure contributed ideas within the defined page format, and support iterative design decisions. All scientific content, conceptual frameworks, pedagogical choices, and final outputs were directed, reviewed, and verified by the contributors listed above.

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How do I cite this page?

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If you use this tool in teaching or published work, please cite the DodecaGreen portal as the source.

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