Table 1.
Main sectors and project types of carbon crediting projects covered by our search terms
| Forestry and land use | |
|---|---|
| Avoided deforestation | Activities designed to reduce deforestation. They are often based on a range of strategies such as improved monitoring, law enforcement and promotion of sustainable land-use practices |
| Improved forest management (IFM) | Applying practices which increase above and below-ground carbon stocks relative to the baseline, including by reducing timber harvest levels, extending timber harvest rotations, designating reserves, reduced impact logging, enrichment planting and stand irrigation or fertilisation |
| Afforestation and reforestation | Planting trees or reducing barriers to natural regeneration |
| Renewable energy | |
| Wind | Installing grid-connected wind power plants, replacing fossil-fuel-based electricity generation |
| Hydropower | Installing grid-connected hydroelectric power plants, replacing fossil-fuel-based electricity generation |
| Solar | Installing grid-connected solar power plants, replacing fossil-fuel-based electricity generation |
| Biomass | Installing biomass-fired power plants, including cogeneration plants, replacing fossil-fuel-based electricity generation |
| Waste management | |
| Landfill methane | Combustion of gas collected from solid waste disposal sites |
| Wastewater | Installation of less greenhouse-intensive wastewater treatment methods |
| Chemical processes | |
| N2O destruction in nitric acid production | Installing abatement measures to reduce N2O emissions from nitric acid plants |
| N2O destruction in adipic acid productiona | Installing abatement measures to reduce N2O emissions from adipic acid plants |
| Hydrofluorocarbon (HFC)−23 destruction | Capturing and destroying HFC-23 produced as a waste gas from HCFC-22 production |
| Sulphur hexafluoride (SF6) replacement and other | Avoiding SF6 emissions by partial or full replacement of SF6 cover gas with alternate cover gases, gas recycling or leak reduction |
| SF6 waste gas destruction | Capturing and destroying SF6 waste gas streams in SF6 production |
| Household and community | |
| Cookstoves | Distributing efficient cookstoves to households or institutions, reducing greenhouse gas (GHG) emissions by using less fuel, burning fuel more completely and/or switching to a less GHG-intensive fuel |
| Industrial manufacturing | |
| Mine methane capture | Flaring or combustion of gas captured from active and abandoned coal and other mines |
| Natural gas electricity generation | Installing new natural gas-fired grid-connected electricity generation plants, replacing fossil fuel-based electricity generation |
| Associate gas recoverya | Avoid flaring of associated gas in oil and gas production |
| Energy efficiencya | Improvement of energy efficiency in industry such as recovery and utilisation of waste heat |
| Avoiding uncontrolled fires from coal waste pilesa | Avoiding GHG emissions from uncontrolled fires from coal waste piles, e.g. by extracting coal from the piles, leaving bare rock which does not ignite, or extinguishing the fires |
| Carbon capture and storage | |
| Carbon capture and enhanced oil recovery | Capturing carbon dioxide from industrial processes followed by compression, transport and injection for permanent storage underground while also enhancing oil recovery |
Based on the classification from the Berkeley Carbon Trading Project30, the Clean Development Mechanism (CDM)28, the Danish Technical University and United Nations Environment Programme (UNEP DTU)31, and the Carbon Credit Quality Initiative (CCQI)11.
aPlease note that these project categories did not have specific search terms but were covered by the generic search terms (see Supplementary Tables 2 and 3, under ‘generic’).