Climate change has both positive and negative implications on rail transport.
Climate change increases the risk of service disturbances in rail transport and can damage railways. Rail transport is especially vulnerable to extreme weather events, because there are few alternative routes. Rail transport is expected to increase in the future.
Significance of rail transport to the transport sector
Per capita, Finland's railway network is the most extensive in Europe. It extends from Hanko in the south to Kolari and Kemijärvi in the north. More goods are transported by rail than passengers. In 2009, rail transport accounted for approximately one quarter of all goods transport, while only five percent of passenger transport was by rail.  Goods transport by rail is expected to increase further in the future, due to higher volumes of timber deliveries and transport associated with mining, for example. Passenger transport by rail is also expected to increase, especially in the Helsinki area. The increasing costs associated with other forms of transport as a result of emissions trading, congestion charges, and other measures relating to climate policy, may increase the popularity of rail transport in the future.  Rail transport to Russia is also on the increase thanks to better rail links.
Sensitivity of rail transport to weather and climatic factors
Railways and rail transport are sensitive to the effects of many weather events. Weather events that can disrupt traffic and compromise safety in rail transport include, among others, rainstorms and the resulting floods, heat waves, freezing, snowfall, violent winds, thunder, and rising sea levels. Rail transport is especially vulnerable to service disruptions, because there are few alternative routes. A single incident may therefore affect many trains, and disruptions may take a long time to clear.  
Effects of climate change on rail transport
Service disruptions resulting from weather cause delays and congestion in rail traffic and may lead to damage and accidents. The higher the speeds and the busier a railway line, the more significant are service disruptions. The scope and scale of the effects of climate change on rail transport cannot yet be estimated accurately, and not enough information has been compiled on service disruptions so far.  
The increasing severity and likelihood of extreme weather events is expected to accelerate wear on railways and equipment as climate change progresses. The increasing frequency of rainstorms and the resulting floods cause erosion and make the ground around rail tracks less stable. Increasing rainstorms may also cause the capacities of drainage wells and tunnels as well as bridge arches to be exceeded. Increasing rainfall is expected to raise water levels and groundwater levels, which is likely to make railway infrastructure less stable and increase the risk of damage. Although snow cover is estimated to decrease on the whole, the intensity of short-lived snow showers and snowstorms is likely to increase. This causes problems in terms of railway equipment, such as blockages and failures as well as frozen points.  
Violent winds are expected to become somewhat more common with climate change. The period of ground frost is also expected to become shorter, which leaves tree roots more exposed and makes trees more likely to fall in violent winds. The increasing likelihood of trees falling on rail tracks or on overhead lines is damaging to rail transport.  
Climate change also has positive implications on rail transport. The increasingly mild winters are expected to reduce the likelihood of frost damage to railways. Higher winter temperatures mean a shorter winter maintenance season in Southern Finland. With sub-zero temperatures becoming increasingly rare, the need for anti-icing and de-icing in the form of ice removal and salting decreases. However, the need for anti-icing and de-icing is expected to increase in Northern Finland due to the increasing frequency of melt-freeze cycles.  
Higher summer temperatures may increase track warpage. Thermal expansion may cause overhead lines to sag in hot weather, and safety devices may overheat. The frequency of thunder is also expected to increase somewhat with climate change. Thunder can damage electricity supply to rail transport and cause faults in traffic signalling systems and safety devices.  
Preparing railways for the effects of climate change
Different kinds of warning systems and weather forecasts about treacherous track conditions and the risk of flooding are vital for preparing rail transport for the effects of climate change. Railway operators can prepare for service disruptions by means of contingency planning and preparedness exercises. Contingency planning involves identifying alternative routes and ensuring the availability of emergency resources such as pumps, construction materials, and machinery. 
Damage caused by falling trees can be mitigated by cutting down trees in high-risk areas and by widening the no-tree zone around railways. However, any affected landowners must be consulted before making these changes. Flooding on railway embankments can be prevented by monitoring the functioning of drainage systems and by improving them. Overhead lines and traffic signalling systems may also need to be protected more efficiently in order to reduce the risk of service disruptions during storms and in thundery weather.