Carbon Budget (model laws definition for the UK) meaning

In practice, a carbon budget is the statutory cap on the UK’s economy-wide greenhouse gas emissions (in tonnes of carbon dioxide equivalent) over each five-year period. Defined in the climate change Act 2008, it is set by the Secretary of State by statutory instrument under sections 4 and 8 to keep the UK on track to the section 1 net zero 2050 target. Current UK budgets are: (a) 2018–2022: 2,544,000,000 tCO2e (Carbon Budgets Order 2009, SI 2009/1259, art 2(c)); (b) 2023–2027: 1,950,000,000 tCO2e (Carbon Budget Order 2011, SI 2011/1603, art 2(c)); (c) 2028–2032: 1,725,000,000 tCO2e (Carbon Budget Order 2016, SI 2016/785, art 2(c)); and (d) 2033–2037: 965,000,000 tCO2e (Carbon Budget Order 2021). Carbon budgets guide decarbonisation policy, carbon accounting and compliance across energy, planning and environmental law, and are applied consistently across England & Wales, Scotland and Northern Ireland. In Ireland, “carbon budget” is separately defined and set under the Climate Action and Low Carbon Development (Amendment) Act 2021.