Hello again, good VGC folk. Some of you might know about the book called "How to Avoid Huge Ships" by captain John W. Trimmer who got a bunch of hilarious meme reviews on Amazon and so. Well, this is about it. Sort of.
Now, let's imagine for a second Elon Musk realizes his grand dream, stop running his company on a loss for once and end up swapping every oil-based car in the world for an electric equivalent. The world is saved, right? No more global warming will drown Disneyworld and kill of exhaustion those poor polar bears.
Automobiles, put together, are only a tiny part of transportation and energy use nowadays: you have airplanes, trucks, ships and trains as well. Except for maybe trucks, all of those are colossal on size and energy demand. For instance, an Boeing 747 cruising will burn about a gallon of fuel a second. Much harder to swap an oil tank for batteries when your power requirements are 100 times higher than for cars!
But I don't want to focus on airplanes here, but shipping, as the thread title might indicate. Not only ships burn low grade cheap fuel full of cancer and asthma causing pollutants, such as sulphur oxides, but they do so on a very, very inefficient fashion. And they aren't even fast as airplanes to compensate. Indeed, the ~15 largest cargo vessels, alone, emit more of those polutants over a year than the combined car fleet of the entire world (close to 800 million vehicles nowadays).
Now, you might argue those ships transport a fuckton of containers - over 500,000 square meters of cargo for the largest ones, to be precise - so the comparison isn't exactly fair. However, the combined gross tonnage of the ~15 largest ships put together, and divided by the combined car fleet in the world, would equal a tiny volume for every car - no larger than a suitcase indeed. And I doubt carrying a packed suitcase over a year on your vehicle would double its emissions during this period, so yeah.
TL, DR: tourism is bad for nature and your health, and importing PlayStations from China even more so. Buy locally and sell locally whenever you can, and travel on light vehicles.
And no, being a vegan and importing soy and lenses, or exotic vegetables, from the other side of the world, isn't going to save the planet because there's one less cow farting methane out there.
PS. the energy used on transportation is also much larger than the entire consumption of electric energy, if I'm not mistaken, so the same thinking also applies for those too focused only on the environmental damage caused by fossil fuel power plants.