The Global Environment Facility (GEF) is a small but critical source of climate finance and has built an investment portfolio that addresses emissions from the transport sector in developing and transitioning countries. The GEF has invested more than $3.6 billion in mitigating climate change since its inception. Unfortunately, there has been consistent under-investment in the very sector in which GHG emissions are growing the fastest. Despite this, the GEF remains an important tool for building in the transport sector. It is crucial that this continues to be the case.