"The Urban Butterfly Effect” a policy brief with recommendations for national governments to accelerate urban efforts to help them achieve the Global Biodiversity Framework (GBF) 2030 Action Targets. This policy brief is a response to the call from the Plan of Action on Subnational Governments, Cities and Local Authorities for Biodiversity for a whole-of-government approach to be adopted. Local governments are key players that can engage with and contribute to the implementation of the 2030 Action Targets. Moreover, local efforts need to be scaled up and universally undertaken in a coordinated and strategic manner. When done so, the benefits of these coordinated local actions would be felt around the world in a phenomenon we call the Urban Butterfly Effect. However, local governments will need support from larger governmental scales if they are to act more universally. This brief aids in implementing such universal action by providing direction as to the specific supports national governments can provide and the potential impact of these supports.