London Climate Action Week (LCAW) was founded in 2019 by E3G in partnership with the Mayor of London. It is the largest city-wide climate festival in Europe and one of the world's largest independent climate change events.

Its mission is to harness the unique power of London for global and local climate action. It mobilises London’s unparalleled ecosystem of climate and non-climate organisations to accelerate global climate action and supports action in London to ensure it acts as a global climate leader.  

London Climate Action Week showcases London as a leading example of how the whole of society can come together to shape and drive climate action.