To reach the long-term temperature goal of the Paris Agreement, most countries will need to reduce emissions to net-zero in 2050 or shortly thereafter. This report considers this challenge from a sector perspective, examining decarbonisation from several different angles. For the following five key sectors: power, industry, transport, buildings, and agriculture, forestry and other land-use, it highlights the leading mitigation options and their implications for longer-term planning. The report further describes how modelling and developing scenarios can support mitigation planning, and how political economy analysis can complement technology focused approaches to get a better understanding of the feasibility of sector transition pathways.