This article considers the issues surrounding climate change and the rail industry in two ways. First, it discusses the role that railways could play in reducing overall greenhouse gas (GHG) emissions and thus help to reduce and mitigate the global temperature increase that will occur over the coming decades. It is argued that, while railways in general have lower emissions than other modes, if a significant decrease in emissions is to be attained, then the capacity of the current rail network needs to be greatly increased to encourage a significant modal shift from road and domestic air travel. Electrification and the provision of high-speed lines can also play a role in this regard, but only if the power that is drawn from the grid is supplied by low carbon sources. Second, the article considers the effect of climate change on the operation of the railway in the next few decades and the adaptations that will be required. The main effects of such changes are likely to be an increase in the track buckling problem, severe strain on railway drainage systems, and the increased likelihood of disruption because of extreme weather events. Ongoing work in this field, aimed at making the railways more resilient, is discussed. It is concluded that, for each of the two areas considered, there is a need for overall system modelling, both to fully evaluate possible mechanisms to reduce GHG emissions, taking account of transfer between modes, capacity limitations, and the national energy mix; and to properly evaluate the major climate change risks to railway operation and to prioritize the use of resources in tackling these issues.