The United States still has a vast lead in carbon dioxide emissions per person. The average American is responsible for 19.4 tons. Average emissions per person in Russia are 11.8 tons; in the European Union, 8.6 tons; China, 5.1 tons; and India, 1.8 tons.
Several things to note about this. First, while China’s large and growing emissions lead means that they’re going to remain a focus of international pressure, cries from American figures that China needs to take the lead before we do anything are a little silly, since the average Chinese person emits just a fourth as much as the average American (and the average Chinese person is quite a bit poorer than the average American). But China is terrifying, because we can expect per capita emissions to reach European levels, at least.