OK, here’s a post that’s NOT about cars. Mostly.

As regular readers of this blog know, Eric and I have been obsessing about transportation fuels for months. Why? Well, because cars and trucks are far and away the biggest source of climate-warming emissions in Western US and Canada. As of 2004, for example, transportation represented more than half of all energy-related CO2 emissions in Washington, Oregon, and California—with cars and light trucks accounting for the lion’s share of transportation GHGs. By any measure, our vehicles have an outsized impact.

Yet globally, transportation isn’t nearly as big a deal. By one estimate (see chart below), global emissions from cars, trucks, boats, trains, and airplanes accounted for only about 14 percent of worldwide GHG emissons in 2000. Compared with other GHG-emitting sectors, transportation ranked 3rd, behind electric power and industrial emissions.

Global greenhouse gas by sector Robert A. Rohde- 360Moreover, while personal vehicles (cars and light trucks) dominate transportation emissions in North America, they represent a somewhat smaller share of transportation emissions in other nations. I’m not trying to say that that cars & trucks aren’t a big deal worldwide. They are. Still, other issues loom even larger.

  • Also—looking more broadly at other data sources—transportation may fall to fourth place. According to some credible estimates, forest clearing and land uses changes account for a full 18 percent of global GHG emissions, not the 10 percent mentioned in the chart above. Globally, land use change is every bit as important as transportation, and probably moreso.

    I don’t think this is going to put a halt to my obsession with transportation fuels. But it is worth remembering that our somewhat singleminded concern about cars and SUVs is, all things considered, more of a local phenomenon than a global one.

    Image courtesy of Robert A. Rohde. Distributed under Creative Commons Attribution-NonCommercial-ShareAlike License, Version 2.5. See more here.