Climate policy & equity
Historical Emissions
The cumulative greenhouse gases a country or group has emitted since industrialisation — the empirical basis of common-but-differentiated responsibility.
Definition
Historical emissions are the cumulative quantities of greenhouse gases — most often CO₂ from fossil fuels, industry, and land use — that a country or economy has released into the atmosphere since a reference point, conventionally 1850. Because CO₂ persists for centuries, cumulative emissions rather than annual flows determine each country's contribution to observed warming, and they underpin the UNFCCC principle of common but differentiated responsibilities.
References
cumulative shares and negotiation relevance
Overview
What it means
Today's developed economies account for the largest share of cumulative emissions since 1850, while low-income countries' share remains a few per cent — the arithmetic behind equity arguments for climate finance, loss and damage, and differentiated mitigation obligations.
At the same time, emissions growth now comes predominantly from developing economies, which complicates the narrative but not the stock of responsibility already in the atmosphere.
How it is used
Historical shares feature in UNFCCC negotiations, fair-share and carbon-budget analyses, climate-finance debates, and litigation.
Why it matters
Who caused the problem is a factual question with distributional consequences; historical emissions are how the world keeps score.
Review
Public comments appear only after editor acceptance. Draft comments stay in the review queue.
Reviewers choose the definition or an overview paragraph, leave a comment or replacement, and attach evidence or a source link.
Editors compare reviewer cards side by side. AI may help find agreement, conflicts, unsupported claims and possible source issues.
Only an editor-accepted synthesis changes the public page. Reviewer identities are shown only with consent and an editorial decision to attribute them.
Submitted reviews stay private until an editor decides whether to accept and attribute them.
Contribute to this entry
Help improve this definition
Your contribution is private while it is checked. Nothing changes on this page unless an editor accepts it.
Loading verified endorsements… Endorsements are not votes and never determine publication.
Endorse this definition
Endorse the exact version shown here. This is not a vote, and publication remains an editorial decision.
Review board
Comment on a specific line. Each reviewer stays separate until an editor accepts a merged draft.
Each person comments on the definition or overview in their own draft card, with role, evidence and suggested wording kept together.
AI can compare comments against the current text, flag conflicting claims, surface missing evidence and identify where reviewers agree.
An editor merges compatible suggestions into a draft change, checks sources, records disagreements and decides what can be published.