Abstract
Long Term Scenarios (LTSs) of development can be co-created to form a joint vision of a development path. Open approaches help improve, transparency, trust, and accountability. Once a LTS is defined, governments can match financing sources and instruments to deliver the measures and projects defined in the LTS, providing signals to align broader finance flows towards the lower carbon economy. This exercise can increase access to and effectiveness of international climate finance. This is illustrated with a case example of Costa Rica, where the data-driven and stakeholder-codesigned National Decarbonization Plan (the country's LTS) launched in 2019 has been the foundation on which at least US$2.4 billion has been mobilized from international concessional finance sources by the end of 2022. An essential effort underpinning this was a carefully crafted and nationally owned LTS study – together with public-good schools and models – that cost less than US$200k to implement.