In the world the CO2 emissions corresponding to the transport sector sum a 22% of the total.
Nonetheless this percentage varies seriously from country to country. Among the top emitters (next table), China and India do not reach the 10% emissions by transport, Germany and Japan are close to 18%, the USA are around 26% and some like Mexico or Brazil are above 35%. So transport is very important depending on the location.
| Transport Emissions | Road Emissions | |
| People’s Rep. of China | 7.04% | 5.48% |
| United States | 30.21% | 26.09% |
| India | 9.93% | 8.90% |
| Russian Federation | 15.30% | 8.85% |
| Japan | 19.48% | 17.59% |
| Germany | 19.11% | 18.51% |
| Korea | 15.41% | 14.52% |
| Canada | 31.62% | 26.02% |
| Islamic Rep. of Iran | 23.31% | 23.07% |
| United Kingdom | 24.67% | 22.90% |
| Saudi Arabia | 23.42% | 22.93% |
| Mexico | 36.31% | 35.34% |
| Indonesia | 25.75% | 22.59% |
| Italy | 27.13% | 25.58% |
| Brazil | 42.82% | 38.22% |
| Australia | 21.44% | 18.01% |
| France | 34.56% | 33.06% |
| South Africa | 11.01% | 10.23% |
| Poland | 15.34% | 14.99% |
| Chinese Taipei | 13.12% | 12.69% |
| Spain | 36.42% | 31.73% |
Next histogram includes the distribution of these topo emitters but also the whole world, and in this case the panorama is even more complex with a range from less than 10% of the share until more than 90%.
Histogram of the transport share in country CO2 emissions for two populatios: All the world and the top 20 emitters, source of data IEA
Anyway, one thing is quite regular for all of them road is the main transport emission source, a 16% around the world but up to 80% in Congo or 35% in Mexico.
Meanwhile, americans are driving less, (reducing that 26%) some also talk about peak car there. One thing is clear, if we want to mitigate climate change, we will have to drive less (mas transit, bicycle, or just walk), do it more efficiently or change cars technology or all at the same time. In some cases it is not difficult to start saving CO2.
Amateur Climate Change 
Comments on: "Transportation, mainly the road" (2)
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