carbon budget

From carbon +‎ budget; widely used in climate science (e.g., IPCC) for the cumulative amount of CO₂ compatible with a given warming limit.

• IPA^(key): /ˈkɑː.bən ˈbʌdʒɪt/ (UK), IPA^(key): /ˈkɑɹ.bən ˈbʌdʒɪt/ (US)

• Audio (US):

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carbon budget (plural carbon budgets)

1. (climatology) The maximum cumulative amount of anthropogenic carbon dioxide emissions compatible with a given global-warming target (e.g., 1.5 °C), for a stated probability and from a stated baseline date.
   • 2019 January 25, 4:09 from the start, in Our House is on Fire‎^[1], spoken by Greta Thunberg, Davos, Graubünden, Switzerland: World Economic Forum:

     People are not aware that there is such a thing as a carbon budget, and just how incredibly small that remaining carbon budget is.

2. (policy, management) An emissions cap or allocation set for a period (year, multi-year, etc.) for a country, organisation, sector, or project so as to follow a target trajectory.
   • 2022 August 22, Phoebe Weston, “England’s housing strategy would blow entire carbon budget, says study”, in The Guardian‎^[2]:

     The building of new homes under a business-as-usual scenario … would mean the housing system would use up 104% of the country’s cumulative carbon budget by 2050.

3. (by extension) A planning document detailing such caps and their trajectory (e.g., a university’s “2024–2028 carbon budget”).

• Sense 1 is the scientific definition (cumulative, linked to a temperature goal); sense 2 is the public-policy/organisational tool (periodic caps).
• Budgets are most often expressed in **CO₂** only; sometimes in **CO₂e** (including other greenhouse gases as CO₂-equivalents).

• emissions budget (sense 2)
• emissions cap (sense 2)

• remaining carbon budget
• national carbon budget, sectoral carbon budget
• personal carbon budget

• Carbon budget (Wikipedia)
• budget carbone (French Wiktionary)

• carbon budget on Wikipedia.Wikipedia