Carbon Markets & Offsets — EU ETS, Voluntary Carbon Markets, Credit Quality & the Role of Carbon Pricing
Carbon markets are policy instruments that create a financial incentive to reduce greenhouse gas emissions by attaching a price to carbon. They fall into two categories: Compliance markets (cap-and-trade systems or carbon taxes mandated by regulation) and Voluntary Carbon Markets (VCMs), where companies and individuals purchase carbon credits of their own accord to offset emissions. As of 2024, 73 carbon pricing instruments are operating globally, covering ~23% of global greenhouse gas emissions — but the weighted average carbon price is still only ~$5/t CO₂e. The IPCC estimates that carbon prices need to reach $130–300/t CO₂e by 2030 to be consistent with 1.5°C. The EU ETS (Emissions Trading System), at €60–80/t, is the world's most significant compliance market; the US has no federal carbon price but the IRA's clean energy subsidies function as an implicit carbon price. The Voluntary Carbon Market peaked at ~$2B in 2021 before a credibility crisis in 2022–2023 raised serious questions about credit quality, additionality, and corporate greenwashing. The market is now reforming around stricter standards under the ICVCM Core Carbon Principles and VCMI Claims Code.
73 instruments
Active carbon pricing instruments globally (2024); covers ~23% of global GHG emissions; includes 36 ETSs + 36 carbon taxes; World Bank Carbon Pricing Dashboard 2024
€60–80/t CO₂
EU ETS carbon price range 2023–2024; world's largest compliance carbon market; covers power, industry, aviation; ~40% of EU emissions; peaked ~€100 in Feb 2023
~$130–300/t
Carbon price needed by 2030 for 1.5°C pathway per IPCC AR6; median ~$180/t; current global weighted average ~$5/t — massive gap; most compliance markets still below required level
~$1B (2023)
Voluntary Carbon Market total value 2023; down from ~$2B peak in 2021; credibility crisis from Guardian/Berkeley investigations into REDD+ over-crediting; reform underway
ICVCM / VCMI
Integrity Council for Voluntary Carbon Markets (ICVCM) — sets Core Carbon Principles (CCPs); VCMI — Voluntary Carbon Markets Integrity Initiative (corporate claims code); two-tier quality reform
Article 6 (Paris)
Paris Agreement mechanism for international carbon credit trading; Article 6.2 (bilateral) and 6.4 (UN market); long-delayed implementation; COP28 2023 partial agreement; potential to integrate VCM into UNFCCC framework
Global Carbon Pricing Coverage — % of GHG Emissions Under Price (by region)
Source: World Bank 2024 (State and Trends of Carbon Pricing); ICAP 2024 (Emissions Trading Worldwide Status Report); IMF 2023 (Carbon Pricing: What Role for Border Carbon Adjustments?); OECD 2023 (Effective Carbon Rates 2023).
Two Types of Carbon Markets
Compliance markets (mandatory): Regulated by governments. Include cap-and-trade systems (ETS — Emissions Trading System) where a total cap on emissions is set and permits are auctioned or allocated; and carbon taxes where a fixed price is charged per tonne of CO₂ emitted. Compliance markets are obligatory — regulated entities must hold permits to cover their emissions or pay the tax.
Voluntary Carbon Markets (VCM): Companies, investors, or individuals voluntarily purchase carbon credits (typically 1 credit = 1 tonne CO₂ avoided or removed) to offset their own emissions. Credits are generated by projects such as reforestation, avoided deforestation (REDD+), cookstoves, methane capture, DAC, or soil carbon. No legal obligation — entirely demand-driven. Quality and integrity vary enormously.
Combined revenue (compliance) 2023~$104B globally; EU ETS ~$58B; China ~$5B; California ~$4B; RGGI ~$1B; UK ETS ~$6B; Korea ETS ~$1B; World Bank 2024
Source: World Bank 2024; ICAP 2024; Ecosystem Marketplace 2023.
Key Compliance Carbon Prices ($/t CO₂e, 2024)
Source: World Bank Carbon Pricing Dashboard 2024; ICAP 2024 (EU ETS, CA, RGGI, Korea, UK, NZ); Canadian government 2024 carbon tax schedule; Singapore government 2024; CBAM (EU Border Adjustment Mechanism) 2024 transition phase data.
Major Compliance Systems
EU ETS (2005–present)World's largest; covers power, heavy industry, aviation, shipping (added 2024); ~40% of EU GHG; Phase 4 (2021–2030) tightened cap; ~1.5Gt CO₂/yr cap (declining); Innovation Fund funded by ETS revenues; €60–80/t 2023–2024
China ETS (2021–)World's largest by coverage (emissions); only covers power sector currently; ~8 Gt CO₂/yr; price ~¥60–90/t (~$8–12); intensity-based (not absolute cap); expansion to industry planned 2025+
California Cap-and-Trade (2012–)Linked with Québec; covers ~85% of California GHG; ~$30–40/t; allowance floor price; offsets allowed up to 8%; auction revenue ~$4B/yr invested in clean energy
RGGI (2009–)Regional Greenhouse Gas Initiative; 11 US northeast states; covers power sector; ~$13–15/t; smaller scale; positive price signal; revenues fund energy efficiency
Canada federal carbon tax (2019–)C$80/t (2024), rising to C$170 by 2030; most comprehensive in North America; rebated to households; OBPS (Output-Based Pricing System) for large emitters; politically contested (fuel charge suspended 2024)
EU Carbon Border Adjustment (CBAM, 2023–)Transition phase 2023–2025; full implementation 2026; covers steel, cement, aluminium, fertilisers, power, H₂; importers must buy CBAM certificates at EU ETS price; prevents carbon leakage
Source: World Bank 2024; ICAP 2024; Government of Canada 2024; EU Commission CBAM 2024; California ARB 2024.
Voluntary Carbon Market — Transaction Value 2016–2023 ($B)
Source: Ecosystem Marketplace 2023 (State of the Voluntary Carbon Markets 2023); MSCI Carbon Markets 2023; BloombergNEF 2023 (Voluntary Carbon Markets: 2023 Market Outlook); Climate Focus 2023; Carbon180 2023.
VCM Categories & Credit Types
Avoided deforestation (REDD+)~33% of VCM by volume; largest category historically; protects existing forests; highly contentious: Guardian/Berkeley investigations (2023) found up to 94% of Verra REDD+ credits may be worthless (phantom credits); most scrutinised
Renewable energy (RECs)Wind/solar RECs; largest by volume historically; but "additionality" weak — most projects would have been built without credit revenue; SBTi guidance: RECs don't count toward Scope 2 offsets (location-based accounting)
Cookstoves / household energyReplaces kerosene/biomass with cleaner stoves; ~15% VCM; challenged by: baseline over-estimation, usage assumptions, leakage; Gold Standard projects generally higher quality
Blue carbon (mangroves/seagrass)High additionality; genuine co-benefits (biodiversity, fisheries, coastal protection); smaller market; durability risk (storms, sea level rise); premium pricing $20–50/t
Carbon removal credits (CDR)Biochar, BECCS, DAC, enhanced weathering; rapidly growing; highest quality + durability; typically $100–1,000/t; Stripe, Frontier, Microsoft buyers; tiny volume vs. avoidance credits
Source: Ecosystem Marketplace 2023; The Guardian / Berkeley investigation Jan 2023; South Pole GmbH scandal 2022; Verra response 2023; BloombergNEF 2023.
Credit Quality Framework — Key Integrity Criteria
Source: ICVCM Core Carbon Principles 2023 (icvcm.org/core-carbon-principles); VCMI Claims Code of Practice 2023; Oxford Offsetting Principles 2020 (Smith School); Schwartz et al. 2022 (Nature Climate Change — offset quality analysis); Gillenwater 2012 (GHG Management Institute — additionality definition).
What Makes a Good Carbon Credit?
The "core criteria" of carbon credit integrity:
AdditionalityWould the emissions reduction or removal have happened anyway without the credit revenue? Non-additional credits have zero climate value but still cost money
Measurability / MRVCan the emission reduction be accurately measured, reported, and verified (MRV)? Remote sensing, direct measurement, or modelling?
PermanenceIs the carbon removal/avoidance permanent? Forest credits can be reversed by fire, disease, political change. DAC/biochar/mineralised storage = permanent; forests = temporary
LeakageDoes protecting one forest just shift deforestation elsewhere? REDD+ leakage up to 40% in some studies
No double-countingIs the emission reduction counted both by the host country in its NDC and by the buyer? Paris Agreement Article 6 "corresponding adjustments" meant to prevent this — not yet universally implemented
Co-benefitsBiodiversity, livelihood, water benefits add social value but don't change carbon accounting. Premium market segment. SDG certification from Gold Standard
Source: ICVCM 2023; Oxford Offsetting Principles 2020; Schwartz et al. 2022; VCMI 2023.
The 2023 REDD+ credibility crisis: In January 2023, The Guardian and Berkeley researchers published investigations finding that up to 94% of rainforest offset credits approved by Verra — the world's largest carbon standard — were "phantom credits" that didn't represent real carbon savings. The methodologies used to estimate "baseline deforestation" (what would have happened without the project) were dramatically over-estimated, creating paper credits with little real-world impact. Projects in Cambodia (South Pole), Zimbabwe (Kariba), and the Amazon were highlighted. South Pole GmbH — the world's largest carbon credit broker — discontinued sales of its flagship Kariba project. Verra announced methodology reforms. The crisis collapsed demand for avoided deforestation credits and accelerated the shift toward higher-quality removal credits. It also prompted the ICVCM to fast-track its Core Carbon Principles (CCPs) as a quality floor.
VCM Credit Issuance by Major Registry (Mt CO₂e, 2022)
Source: Ecosystem Marketplace 2023; Trove Research 2023; South Pole 2022 (before Kariba scandal); Gold Standard Annual Report 2022; American Carbon Registry 2022; Climate Action Reserve 2022; Verra VCS database 2022.
Key Registries & Standards
Verra VCS (Verified Carbon Standard)Largest registry; ~70% of VCM by volume; issues Verified Carbon Units (VCUs); REDD+ dominant; under scrutiny post-2023; CCB (Climate Community and Biodiversity) add-on standard; reforming methodologies
Gold Standard (founded WWF)Founded 2003; higher quality threshold; strong SDG focus; household energy, clean water prominent; smaller volume but better additionality record; CCP-eligible in ICVCM review
American Carbon Registry (ACR)Oldest in US (1996); focus on N. America; covers soil carbon, forestry, methane; now part of Winrock International; accepted in California cap-and-trade
Climate Action Reserve (CAR)US-focused; high MRV standards; accepted in California; methane, US forests, ozone; conservative baselines; smaller but high integrity
ICVCM (meta-standard)Not a registry — assesses existing registry programmes against Core Carbon Principles; "CCP-approved" label = quality floor; first approvals announced 2024; aims to restore VCM confidence
Puro.earth / Xpansiv / CBLPuro: focuses on engineered CDR (biochar, building materials, BECCS, DAC); Xpansiv/CBL: spot market exchange for carbon credits; growing liquidity infrastructure
Source: Ecosystem Marketplace 2023; Verra 2022; Gold Standard 2022; ICVCM CCP assessment 2024; Puro.earth 2023.
EU ETS vs VCM Price Trends (€/$ per t CO₂, 2018–2024)
Source: ICAP 2024 (EU ETS price data); Ember Carbon Price Tracker 2024; Ecosystem Marketplace 2023 (VCM price data); BloombergNEF 2023 (VCM price tracker); S&P Global Platts Carbon 2024; Trove Research 2023.
What Drives Carbon Prices?
Gas/coal price spread (EU ETS)When gas is cheap relative to coal, utilities switch to gas = less EUA demand = lower price. 2021–2022 energy crisis spike: gas prices surged, utilities burned more coal, EUA demand spiked → €100 peak
Cap tightening speedEU ETS annual cap reduction = Linear Reduction Factor (LRF); increased from 1.74% to 2.2% (Phase 4) to 4.3% (from 2024) under Fit for 55; faster tightening = higher forward expectation
Market Stability Reserve (MSR)EU ETS mechanism that absorbs surplus allowances automatically; stabilises price floor; reformed 2019 → major price driver to 2021 rally
VCM price: quality and typeVCM prices vary enormously: REDD+ avoidance ~$3–8/t; cookstoves ~$5–15/t; blue carbon ~$20–50/t; DAC ~$400–1,000/t; biochar ~$100–300/t; large quality-price spread reflects integrity variation
SBTi limits on offsetsScience-Based Targets initiative (SBTi) does not allow companies to use VCM offsets to count toward Scope 1/2 reduction targets — only residual value neutralisation; limited offsets' corporate demand ceiling
Source: ICAP 2024; Ecosystem Marketplace 2023; BloombergNEF 2023; SBTi Corporate Net Zero Standard 2021.
The Carbon Border Adjustment Mechanism (CBAM) — reshaping global carbon pricing: The EU's Carbon Border Adjustment Mechanism, entering its transition phase in 2023 and full implementation in 2026, requires importers of carbon-intensive goods (steel, cement, aluminium, fertilisers, electricity, hydrogen) to purchase CBAM certificates equivalent to the EU ETS carbon price. This prevents "carbon leakage" — the outsourcing of production to non-carbon-priced jurisdictions — and creates a powerful economic incentive for trading partners to establish domestic carbon pricing. The CBAM effectively exports the EU ETS price signal to global supply chains. Trading partners including the UK, Canada, and Australia are designing their own border adjustment mechanisms. The CBAM is arguably the single most strategically important climate policy development of 2023–2024, as it creates a globally spreading carbon price floor through trade law rather than climate diplomacy.