A to B

Additionality

A project is "additional" if the emission cut or removal would not have happened without the money from selling carbon credits. If a solar plant would have been built anyway because it was already profitable or required by law, credits from it are not additional.

Afforestation and reforestation

Afforestation means planting trees on land that has not been forest for a long time; reforestation means bringing back trees on land that was recently forest. Both can take carbon dioxide out of the air as the trees grow, but only if the trees survive and the land stays forested.

Avoided emissions

Emissions that did not happen because of an action, measured against what would otherwise have happened, for example cleaner cookstoves replacing wood fires. Avoided emissions are not the same as removals: nothing is taken out of the air.

Baseline

The "business as usual" scenario that a project or company compares itself with. A carbon credit is only as reliable as its baseline: if the baseline is set too high, the claimed savings look bigger than they really are.

Base year

The year a company or country uses as its starting point for measuring change. India's emissions-intensity targets, for example, use 2005 as the base year (India's NDC, UNFCCC, 2022 and 2026).

Biogenic carbon

Carbon that comes from living or recently living material, such as wood, crop waste or biogas. Standards such as the GHG Protocol ask companies to report biogenic CO2 separately from fossil CO2.

BRSR and BRSR Core

The Business Responsibility and Sustainability Report is the ESG disclosure format that the Securities and Exchange Board of India (SEBI) introduced in 2021 for the top 1,000 listed companies by market value. BRSR Core, set out in a SEBI circular of 12 July 2023, is a smaller set of key indicators, including greenhouse gas emissions, that must be independently assessed or assured on a glide path from the top 150 listed companies in FY 2023-24 to the top 1,000 in FY 2026-27 (SEBI circular, 28 March 2025).

Buffer pool

A reserve of carbon credits that a forestry or land project sets aside and does not sell. If trees are lost to fire, pests or illegal felling, credits are cancelled from the buffer so that the overall claim stays honest.