What on Earth were they thinking with these comparisons?<p>> The United States alone emits more than 5 billion metric tons of CO2 annually — the weight of 13.2 million fully loaded Boeing 747s, or roughly 68,000 Washington Monuments.<p>I can at least visualize the size of a football field, or the size of an Olympic swimming pool, or something like that. I've no idea how to reason about the weight of a loaded 747 (apparently 379 metric tons?) or the weight of a tall stone building...<p>In any case, I expect the doubling is a good bet. Very few people, including those who claim to care about climate change and have the money to do quite a bit, are actually taking useful actions about the problem, instead acting like voting for the correct person is the least and most one can be expected to do.