This chapter provides an overview of current responses to climate change. It looks at how CO2 emissions from transport may evolve, assuming current energy prices do not change strongly. It discusses road transport, shipping and aviation in relation to CO2 emissions. Transport activities have adverse environmental and health impacts, of which local and regional air pollution, climate change and noise impacts are the most important. This chapter is a non-comprehensive overview of existing and potential policies to deal with these negative impacts, with a focus on international transport. “International transport” is here defined as those transport activities that are mainly derived from the globalisation of economic activity, not as cross-border transport flows in a more narrow sense. Surface transport, aviation and maritime transport are discussed. The focus is on climate change, treating other adverse impacts (including aviation noise and local and regional pollution from shipping) more succinctly. Policies to reduce transport’s greenhouse gas emissions are assessed against the background of a broader discussion of how to deal with the free-rider problem. CO2 abatement in road transport is discussed in some detail, while just a few issues related to maritime transport and aviation are mentioned.