The European Commission proposed allowing up to 3 percentage points of the EU's 2040 target - to cut net emissions by 90% from 1990 levels - to be covered by carbon credits bought from other countries. The EU's existing climate targets require countries to meet the goals entirely by cutting emissions at home.

Cities have a central role to play tackling climate change. They contribute 67%–72% of the greenhouse gas emissions which are heating up the planet.

The European Commission on Wednesday proposed an EU climate target for 2040 that for the first time will allow countries to use carbon credits from developing nations to meet a limited share of their emissions goal.