As you can see from the comparison data, there are some distinct differences between air, rail and sea freight in terms of emissions and distances between Duisburg in Germany and Shanghai in China.
By all accounts, air freight produces the largest amounts of emissions by far! It's only real benefit for freight forwarders would be the low transit time but at a high risk to the environment and with limited storage space per trip.
The real comparison equivalent to rail, is sea freight. Although it beats rail with lower C0₂ and Greenhouse Gas emissions, it unfortunately produces larger amounts of Sulfer Dioxide and Nitrogen Oxides which contribute to climate change and acid rain.
Paired with this, sea freight travels an unnecessary long distance compared to rail with around a 5 week transit time. On the other hand, rail freight's transit time is closer to 12 to 14 days and is more comparable in distance to air freight.
Rail freight meets all the requirements for European and Russian clean energy standards and although it may not be the absolute cleanest emissions option it clearly makes up for it as a fast, reliable and safe way to transport cargo.
Over the past several years there have been many new investments into rail freight. Consider it for your next transport option!
A full PDF of the research data can be found here.
This information was discovered and calculated by EcotransIT World, a web portal which calculates environmental impacts of different carriers across the world. More information can be found at: http://www.ecotransit.org/