One cargo train using energy coming from clean sources (like water or wind) emits cero CO2 emissions.
As we need to face the challenges of a warming planet, measuring and reducing the energy use and CO2 emissions from transportation has become a top priority. New technologies allow a shift to cleaner energy sources for all transport modes and between road and railways, trains are still leading the way.
The widespread use of vehicles running on gasoline and diesel, remains a major source of CO2 emissions in the world. The heavy reliance on private vehicles for transporting just 1-2 persons makes the things worse. Public transport in urban areas with gasoline & diesel sources and traffic jams, does not help either.
One of the primary reasons why trains stand out in the fight against CO2 emissions is their remarkable energy efficiency. Unlike road transportation, which relies heavily on individual vehicles with internal combustion engines, trains are highly energy-efficient. Electric and modern diesel/electric and hydrogen trains have a lower footprint per passenger-kilometer, thanks to their ability to move large numbers of passengers or freight using relatively small amounts of energy.
Illustration source: Norwegian Environment Directorate