FAQ: Emissions and climate

Yes, capture and permanent storage of biogenic CO₂ from biogas upgrading (BECCS) can give net negative emissions, because the CO₂ comes from biomass that earlier took it from the atmosphere.

Biomethane plants have an advantage: the CO₂ separated in the upgrading process is already concentrated (almost pure), so capturing it costs less than at many other sources. Permanent storage or use requires transport, infrastructure and formal confirmation of permanence, and these solutions are at an early stage in Europe. Using CO₂ in short-lived products (e.g. drinks) does not give a permanent negative emission. In practice, therefore, BECCS at biogas plants is a direction of development dependent on regulation, charges and infrastructure.

Sources: IEA — Outlook for biogas and biomethane: prospects for organic growth; IEA Bioenergy Task 37 — Energy from Biogas

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The Green Deal is a strategic document. The Climate Law is a regulation, a binding act, which enshrines the climate neutrality target for 2050 and creates a mechanism for assessing progress.

Sources: Wniosek COM(2020) 80 — europejskie prawo o klimacie (EUR-Lex); Komisja Europejska — europejskie prawo o klimacie

Discussed in the article: The Commission proposes a European climate law: climate neutrality in 2050 as an obligation

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Anaerobic digestion usually has a more favourable climate balance, because in addition to compost or digestate it yields biogas that replaces fossil fuels, while composting – if carried out properly – is simpler and cheaper but produces no energy.

In composting, a poorly aerated windrow can emit methane and N₂O, and the energy contained in the waste is not used. In digestion, the tightness of the installation and of the digestate stores is important, because methane leaks weaken the benefit. In practice, plants often combine both processes: digestion, followed by maturation of the digestate. For green waste, wood and structural material, composting is sometimes better. The choice depends on the type of waste, the scale and local conditions, and not on a single universal rule.

Sources: IEA Bioenergy Task 37 — Energy from Biogas; Dyrektywa (UE) 2018/851 zmieniająca dyrektywę o odpadach — EUR-Lex

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Yes, methane leaks from biogas plants do occur (from valves, digester covers, engines, upgrading and digestate stores), and studies indicate a range from a fraction of a per cent to several per cent of production, so leak control matters economically and for the climate.

Methane that escapes is lost gas and an emission with a high warming potential. The sources are leaks in membranes, pressure relief valves, vents, incomplete combustion in the engine (methane slip) and open digestate stores. They are limited by regular checks with an infrared camera or a detector, sealed covers, good operating practice and servicing. The EU methane regulation applies mainly to fossil fuels, but leak control standards are becoming a benchmark. A single inspection is not enough; a programme of continuous control is needed.

Sources: IEA Bioenergy Task 37 — Energy from Biogas; Rozporządzenie (UE) 2024/1787 w sprawie redukcji emisji metanu w sektorze energii — EUR-Lex

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Biogas plants help the climate mainly when they process waste and animal excreta, because they reduce methane emissions and replace fossil fuels, and their benefit shrinks when they rely on energy crops and have methane leaks.

The greatest benefit comes from installations using slurry, bio-waste and processing residues, which would otherwise emit methane. Much less favourable for the climate are large maize-based installations, because cultivation requires fertilisers, fuel and land, and the impact can include land-use change. The balance is also affected by tightness, use of heat, and the way digestate is stored and applied. This is why EU regulations promote waste feedstocks and require carbon footprint calculations.

Closed digestate tanks are particularly important, also in light of the EU Methane Regulation.

Sources: IEA — Outlook for biogas and biomethane: prospects for organic growth; Dyrektywa (UE) 2023/2413 (RED III) — EUR-Lex; Basic Information about Anaerobic Digestion — US EPA; Rozporządzenie (UE) 2024/1787 w sprawie redukcji emisji metanu — EUR-Lex

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Only if the waste and slurry would otherwise be landfilled or stored in a way that emits methane, and the biogas plant is gas-tight. Leaks from the installation and from open digestate stores can reduce or cancel out the benefit.

Sources: IPCC — Piąty Raport Oceniający (AR5), Grupa Robocza I; Rozporządzenie (WE) nr 1069/2009 — uboczne produkty zwierzęce — EUR-Lex

Discussed in the article: Without biogas plants: what happens to organic waste without controlled fermentation

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Transporting substrates increases emissions, but it is usually a small part of the total carbon footprint as long as distances are reasonable; when moving material over long distances, especially slurry with high water content, the benefit shrinks.

Slurry contains a lot of water, so hauling it tens of kilometres is inefficient in terms of energy and cost. Agricultural biogas plants are therefore located close to the sources of substrates, and deliveries are kept within a reasonable radius. In RED calculations, transport is included in the carbon footprint of the chain. Additional emissions are also caused by the transport of digestate and, in the case of bioLNG, of the fuel. They are limited by: route optimisation, use of gas-powered vehicles and separation of digestate. For residents, transport is also a matter of noise and safety.

Sources: IEA Bioenergy Task 37 — Energy from Biogas; Dyrektywa (UE) 2018/2001 (RED II) — EUR-Lex

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ICAP lists waste among the sectors covered by the scheme. Whether a specific installation is subject to the K-ETS depends on emission thresholds (entity: at least 125,000 t CO₂eq per year and at least one installation above 25,000 t).

Sources: ICAP – Korea Emissions Trading System (K-ETS); ICAP – Korea approves Phase 4 K-ETS allocation plan 2026–2030; IEA – National Emissions Allowance Allocation Plan Phase 4 (2026–2030)

Discussed in the article: K-ETS: how the Korean emissions trading system works and what Phase 4 (2026–2030) changes

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Yes, using heat from cogeneration significantly improves efficiency and the climate balance, because it replaces other heat sources; unused heat means a loss of energy and lower environmental benefits.

A cogeneration engine converts biogas into electricity and heat. Electrical efficiency is usually below half of the fuel energy, and the rest is heat, which can replace e.g. coal or gas in heating. If the heat is only partly used (mainly to heat the digesters), overall efficiency falls. Locating the plant next to a heat customer (a heating plant, an industrial site, greenhouses) therefore improves the result. An alternative is upgrading to biomethane, which can be used where there is demand. The choice depends on local conditions.

Sources: IEA Bioenergy Task 37 — Energy from Biogas; Dyrektywa (UE) 2018/2001 (RED II) — EUR-Lex

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The EU has a target of reducing net greenhouse gas emissions by 55% by 2030 relative to 1990 and by 90% by 2040, with the 2040 target approved by the Council in March 2026.

In 2025–2026 it was also agreed that ETS2 for buildings and road transport would start in 2028 instead of 2027. The 2040 target allows limited use of international carbon credits and permanent removals. The Commission is to review progress every two years and may propose adjustments. Biogas and biomethane support the delivery of the targets by reducing methane emissions from agriculture and waste and by replacing fossil gas. The scale of the contribution depends on how much biomethane is produced and from which feedstocks.

Sources: electrive.com: Rada UE zatwierdziła cel klimatyczny na 2040 r. (marzec 2026); Komisja Europejska — Dyrekcja Generalna ds. Działań w dziedzinie Klimatu

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Ammonia emissions are reduced by application techniques that limit contact of the fertiliser with the air, such as placing digestate directly in the soil (trailing hoses, injection), rapid incorporation, and application in cooler, moist conditions.

Digestate usually has a higher pH and a higher content of ammonium nitrogen than slurry, so its susceptibility to ammonia losses is high. Ammonia is a loss of nitrogen and an air pollutant that leads, among other things, to the formation of fine particulate matter PM2.5. Good practice: application into the soil, avoiding spreading on hot and windy days, covering stores, and using doses in line with the fertilisation plan. The Nitrates Directive and the national action programme (the nitrates programme) limit nitrogen doses. Details on digestate are covered in the FAQ category "Digestate and fertilisers".

Sources: Dyrektywa Rady 91/676/EWG (azotanowa) — EUR-Lex; IEA Bioenergy Task 37 — Energy from Biogas

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For the climate, an incinerator with energy recovery is usually better than a landfill, because a landfill emits methane from the decomposition of organic waste, while an incinerator replaces fossil fuels and does not produce methane; recycling and prevention are better still.

In LCA balances, landfilling of unseparated municipal waste comes out worse because of methane, even with degassing, which does not capture all of it. An incinerator emits CO₂ from burning fossil fractions (plastics) and biogenic fractions, but recovers energy and metals. The result depends on efficiency, the energy mix, the composition of the waste and whether the heat is used. The waste hierarchy and EU targets limit landfilling, and many assessments indicate that the most beneficial for the climate is reducing the amount of waste and recycling it.

Sources: CEWEP — Confederation of European Waste-to-Energy Plants; Dyrektywa (UE) 2018/850 zmieniająca dyrektywę o składowaniu — EUR-Lex

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No, biomethane can replace only part of natural gas, because it is limited by the amount of available waste and residues; in the EU it is today less than a few per cent of gas consumption, and full neutrality also requires efficiency, electrification and other fuels.

According to the EBA, biomethane production in the EU-27 was about 4.3 billion m³ in 2024 against gas consumption of about 332 billion m³, and the REPowerEU target assumes 35 billion m³ by 2030. Even reaching it would cover a small part of demand. Biomethane does, however, have an important role in sectors that are hard to electrify, such as heavy transport, shipping or industrial heat. Realistic potentials depend on feedstocks, which must not compete with food or overuse resources.

Sources: IEA — Outlook for biogas and biomethane: prospects for organic growth; European Biogas Association

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Not always automatically: CO₂ emissions from burning biomass are treated in EU rules as zero at the point of use, but only if the sustainability criteria are met, and the climate assessment covers the whole life cycle, including methane and N₂O from other stages.

The carbon contained in biogas comes from biomass that took CO₂ from the atmosphere relatively recently, so burning it does not add "new" fossil carbon. This does not, however, mean zero impact: cultivation, transport, digestate storage, methane leaks, liquefaction or land-use change can generate emissions. This is why regulations require the carbon footprint of the entire chain to be calculated and verified through certification. The conclusion: biomethane from waste and slurry is usually beneficial, while from intensive crops it calls for caution.

Sources: Dyrektywa (UE) 2023/2413 (RED III) — EUR-Lex; IPCC AR6, Working Group I

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No. Communication COM(2019) 640 is a strategic document. The binding rules arise from later acts, such as the European Climate Law and the "Fit for 55" package.

Sources: Komunikat COM(2019) 640 — Europejski Zielony Ład (EUR-Lex); Komisja Europejska — Europejski Zielony Ład

Discussed in the article: The European Commission presents the European Green Deal: climate neutrality by 2050

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Avoided emissions are the difference between emissions in the reference scenario (e.g. slurry storage or waste landfilling, and the use of fossil fuel) and emissions after the biogas plant starts operating; they cannot be attributed to every biogas plant in the same way.

The value depends on what would happen without the installation: whether slurry would be kept in an open tank, whether the waste would go to a landfill, and what fuel would be replaced. If without the biogas plant the substrate would be managed anyway without large emissions, there are fewer avoided emissions. Reliable figures require a clear reference scenario, data and conservative assumptions. Overly optimistic claims are sometimes criticised; regulations therefore specify methods and credits (e.g. for slurry), which should be applied in accordance with the rules.

Sources: Dyrektywa (UE) 2018/2001 (RED II) — EUR-Lex; IEA Bioenergy Task 37 — Energy from Biogas

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N₂O (nitrous oxide) is a greenhouse gas with a warming potential about 270 times greater than CO₂ over a 100-year horizon (IPCC AR6), which forms in soil after nitrogen fertilisation, including with digestate and slurry.

N₂O emissions depend on the nitrogen dose, soil moisture and temperature, and the method of application. Digestate supplies plants with nitrogen, which can replace mineral fertilisers, whose production is energy-intensive and emission-intensive. For the balance to be favourable, nitrogen must be well used by the plants, and losses (ammonia, N₂O, leaching) limited. Full carbon footprint assessments of biomethane include N₂O emissions from the field and from the cultivation of substrates. They are limited by: precise dosing, timing in line with plant needs and avoiding fertilising waterlogged soils.

Sources: IPCC AR6, Working Group I; Dyrektywa Rady 91/676/EWG (azotanowa) — EUR-Lex

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According to the 2026 Budget, the nominal rate is 308 rand per tonne of CO₂e from 1 January 2026. The actual burden is lower thanks to allowances (initially 60–95%) and the possibility of offsetting.

Sources: Publication of the 2019 Carbon Tax Act — gov.za (26.05.2019); SAICA Sustainability Snapshot, luty 2026 (nr 7) (aktualizacja); Carbon Tax Act, 2019 (Act No. 15 of 2019) — rate of tax; SAICA: komentarze do dokumentu dyskusyjnego Skarbu Państwa o fazie 2 podatku węglowego (grudzień 2024)

Discussed in the article: South Africa's carbon tax rises from 1 January 2026 to 308 rand per tonne of CO₂e

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The Global Methane Pledge is an international initiative from 2021 in which participating countries committed to reducing anthropogenic methane emissions by at least 30% by 2030 relative to the 2020 level.

The commitment is political and not legally binding, and covers, among other things, energy, agriculture and waste. The target builds on the fact that cutting methane gives a quick climate effect, because this gas stays in the atmosphere for a short time. In the EU its delivery is supported by, among other things, the methane regulation (concerning fossil fuels) and regulations in the waste and agriculture sectors. Biogas plants reduce methane emissions from excreta and organic waste. The current list of countries and progress is published by the organisers of the initiative and by the IEA.

Sources: Global Methane Pledge; IEA — Global Methane Tracker 2025

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According to estimates by UNEP and the Climate and Clean Air Coalition, agriculture accounts for about 40% of anthropogenic methane emissions worldwide, mainly from ruminant livestock, slurry and rice cultivation.

The main part is enteric fermentation in cattle and sheep, but a significant share comes from the storage and decomposition of animal excreta. It is this last part that can be reduced by biogas plants, which capture methane from slurry and manure. Ruminant farming remains a large source on which biogas plants have no effect. The share of agriculture in methane emissions in the EU and Poland depends on the production structure and the inventory methodology; current values are published by the European Environment Agency and in national reports.

Sources: FAO — Global Livestock Environmental Assessment Model (GLEAM); Global Methane Pledge; UNEP/CCAC — Global Methane Assessment (komunikat: rolnictwo ok. 40% antropogenicznych emisji metanu)

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The value of 94 g CO₂eq/MJ is the average emission intensity of fossil fuels in transport adopted in the RED II Directive, from which the percentage by which a biofuel reduces emissions is calculated.

It is a reference value (the fossil fuel comparator), used to calculate emission savings. If biomethane has a footprint of e.g. 20 g CO₂eq/MJ, the saving is about 79% relative to 94. The minimum saving threshold required depends on the date the installation was commissioned and on the use of the biofuel. Different reference values are adopted for electricity and heat. It is worth remembering that this is a regulatory value and not a measurement result, so it serves for comparisons and compliance with the rules. Check current values in Annexes V (biofuels) and VI (biomass fuels, including biomethane) to the RED II Directive.

Sources: Dyrektywa (UE) 2018/2001 (RED II) — EUR-Lex; Dyrektywa (UE) 2023/2413 (RED III) — EUR-Lex

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A sealed (gas-tight covered) digestate store retains the methane and ammonia that form after the digestate leaves the digester, and so reduces fuel losses, greenhouse gas emissions and odour nuisance.

Digestate still contains a residual methane potential and in an open tank continues to release gas. In the carbon footprint calculation methodology (RED), open storage of digestate increases emissions, while closed storage with gas recovery reduces them. Covering the tank also allows the gas to be captured and sent to the installation, which improves the balance. This requires a gas-resistant structure, protection against overpressure and safe operation in explosion hazard zones. For residents, a sealed store also means fewer odours.

Sources: IEA Bioenergy Task 37 — Energy from Biogas; Dyrektywa (UE) 2018/2001 (RED II) — EUR-Lex

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Biomethane from slurry can have a negative carbon footprint because digestion prevents the emissions of methane and N₂O that would arise from ordinary storage of slurry, and the RED methodology grants an emissions credit for this (−45 g CO₂eq/MJ of slurry).

Fresh slurry stored in open tanks emits methane. When it goes to a biogas plant, this methane is captured as biogas and replaces fossil fuel, so both emissions are avoided: from storage and from burning natural gas. The emissions calculation methodology in the RED Directive (Annex VI) counts this as a bonus of 45 g CO₂eq per MJ of slurry, which can lead to values below zero for gas from slurry. The result, however, depends on the tightness of digestate storage and on methane losses; there is also an ongoing discussion about the size of the credit.

Sources: Dyrektywa (UE) 2018/2001 (RED II) — EUR-Lex; Dyrektywa (UE) 2023/2413 (RED III) — EUR-Lex

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Energy crops are criticised because they require land, fertilisers and fuels, may compete with food production and lead to indirect land-use change (ILUC), which reduces or cancels the climate benefit.

The RED Directive limits the counting of biofuels from food and feed crops in transport and introduces a category of high ILUC-risk feedstocks, which are being phased out. Crops on marginal land, catch crops or perennial plants may have a better balance than maize in monoculture. The result depends on local conditions, yield, fertilisation and what would be grown without the biogas plant. For the climate, therefore, waste and residues are the most beneficial, and energy crops should be a supplement.

Sources: Dyrektywa (UE) 2018/2001 (RED II) — EUR-Lex; Dyrektywa (UE) 2023/2413 (RED III) — EUR-Lex

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Landfills emit methane because organic waste (food scraps, paper, garden waste) decomposes in them without access to oxygen, producing landfill gas in which methane usually makes up 40–60%.

The gas forms over years, and when it is not captured it escapes into the atmosphere. According to international estimates, the waste sector is a significant source of anthropogenic methane. The most effective way to limit it is to stop bio-waste from reaching landfills: separate collection and digestion or composting. At existing landfills, degassing systems are used. The EU requires municipal waste landfilling to be limited to 10% by 2035 and bans landfilling of waste collected separately that is suitable for recycling.

Sources: Global Methane Pledge; Dyrektywa Rady 1999/31/WE w sprawie składowania odpadów — EUR-Lex

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LCA results for biomethane differ because they depend on assumptions: the type of feedstock, the reference scenario, the allocation method, methane losses, the way digestate is stored, the system scope and the methodology applied (RED, ISO standards, scientific studies).

For the same gas one can obtain a negative or a positive result, depending on whether the avoided emission from slurry storage is counted, how land emissions are calculated and what the methane losses are. The RED methodology is standardised for regulatory purposes and allows default values; scientific analyses are sometimes more detailed. When comparing results, therefore, check the functional unit (e.g. g CO₂eq/MJ), the system boundaries and the assumptions. A reliable assessment requires data from a specific installation.

Sources: Dyrektywa (UE) 2023/2413 (RED III) — EUR-Lex; IEA Bioenergy Task 37 — Energy from Biogas

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Because it lives in the atmosphere for about 12 years and absorbs radiation strongly. Over the short horizon (20 years) its impact is counted in full, over 100 years, after it has decayed, which is why the factor is lower.

Sources: IPCC AR5 — Climate Change 2013: The Physical Science Basis (rozdział 8); UNFCCC — Global Warming Potentials

Discussed in the article: Methane GWP: a 20-year or 100-year horizon? How to calculate the climate impact of biogas

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Methane is a greenhouse gas with a much higher warming potential than CO₂ over a short time horizon, but it persists in the atmosphere for a shorter time. Limiting it quickly slows the rate of warming.

Sources: Komunikat COM(2020) 663 — strategia ograniczania emisji metanu (EUR-Lex); Komisja Europejska — strategia metanowa

Discussed in the article: The Commission presents the EU strategy for reducing methane emissions

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Methane is a much stronger greenhouse gas than CO₂: according to IPCC AR6 its global warming potential (GWP) over a 100-year horizon is in the range of 27–30 and over a 20-year horizon about 80, but it breaks down in the atmosphere within about a decade.

This means that 1 tonne of methane warms the atmosphere like several dozen tonnes of CO₂ over a given period. Its short lifetime means that cutting methane emissions quickly translates into slower warming, which is why it is an important element of climate policy. The sources are agriculture (livestock, slurry), landfills and fossil fuel leaks. Biogas plants reduce methane emissions from excreta and waste, provided they do not themselves have excessive leaks. The exact values depend on the methodology and the version of the IPCC report.

Sources: IPCC AR6, Working Group I; IEA — Global Methane Tracker 2025

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Over the short term, methane has a warming effect many times stronger than CO₂, but it breaks down in the atmosphere within a dozen or so years. Reducing it therefore gives a quick effect.

Sources: IPCC AR6 Working Group I — The Physical Science Basis

Discussed in the article: IPCC report on the physical science basis of climate change: the role of methane and the urgency of cutting emissions

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At unmanaged landfills, organic waste decomposes anaerobically and releases methane, a potent greenhouse gas. Segregation and digestion in a biogas plant make it possible to capture this gas and use it as energy.

Sources: What a Waste — Global Snapshot of Solid Waste Management toward Circularity until 2050 — World Bank Data Topics; African leaders: recycling and health (2022) — Phys.org; Basics of Waste Management — African Clean Cities Platform

Discussed in the article: Waste and methane in Sub-Saharan Africa: what World Bank data say

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In slurry without access to oxygen, bacteria break down organic matter and produce methane, which escapes from open tanks, especially in warm weather, so the decomposition of slurry over months of storage is a source of emissions.

Methane forms under anaerobic conditions, which prevail deep in a slurry tank; the higher the temperature and the longer the storage, the more gas. If the same decomposition takes place in a controlled way in a digester, the gas is captured and used. This is why the RED methodology grants a biogas plant an emissions credit for slurry. For the benefit to be real, slurry should reach the digester as fresh as possible, and digestate should be stored in a sealed or covered tank. Solid manure emits differently, and the scale depends on storage conditions.

Sources: IPCC AR6, Working Group I; FAO — Global Livestock Environmental Assessment Model (GLEAM)

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