The following thought experiment is based on 2018 statistics, which are the latest that I could find (so when I say “current,” I am referring to 2018 values).

[Updated below] Analysis and commentary in US public media most often compare the total greenhouse gas emissions (CO₂e) of China and the US, abstracting from the fact that China has more than 4 times the population of the US. (Also typically left out of such commentary is the enormous historical contribution by the US to CO₂e in the atmosphere.) From this misleading standpoint, one constantly is reminded that China emits more than twice as much CO₂e as the US. 

But from a per capita standpoint — the only rational way to compare the two countries with respect to their contribution to climate change — China emits less than half as much CO₂e as the US.

Even if the US lowers its emissions by 40% compared to 2005 levels — the optimistic estimate based on implementation of the Inflation Reduction Act of 2022 — its per capita emissions would still be 27% higher than China’s current emissions, per capita.

In fact, the US would need to lower its current emissions (which are already 10% lower than its 2005 emissions) by an additional 48% just to match China’s current per capita emissions.

Here are my calculations, and sources:

2018 per capita total greenhouse gas emissions (CO₂ equivalent or CO₂e)

• US: 18.44 metric tons of CO₂e per capita
• China: 8.87 metric tons of CO₂e per capita

2018 population

• US: 327,096,265
• China: 1,427,647,786

2018 Total emission

• US: 6,030 x 10⁶ metric tons of CO₂e
• China: 12,663 x 10⁶ metric tons of CO₂e

Amount of US emissions if made to equal China’s per capita rate

• 8.87 x 327,096,265 = 2,901 x 10⁶ metric tons of CO₂e

Percent reduction in US 2018 emissions to equal China’s 2018 per capita emissions

• (2,901 / 6,030) x 100 = 48%

Other calculations:

• “The goal of the [Inflation Reduction] bill is to put the country [US] on a path to reduce greenhouse gasses by 40 percent below 2005 levels by 2030.” (source)
• “From 2005 to 2018, net US emissions declined 10 percent” (EPA Data highlights)
• Therefore 2005 US emissions were 6,700 x 10⁶ metric tons of CO₂e.
• Therefore, the 2030 US goal of emissions 40% below 2005 levels sets a target of 4,020 x 10⁶ metric tons of CO₂e.
• Assuming a 2030 US Census projected population of 355,100,000, the per capital goal for 2030 US emissions is 4,020 x 10⁶ / 355,100,000 = 11.32 metric tons of CO₂e per capita.
• This is substantially higher than the current (2018) Chinese per capita emissions of 8.87 metric tons of CO₂e per capita.

Updated 16 September 2022: Here is a typical and egregious example of how China is portrayed in US media as “the world’s largest climate polluter” even though its per capita contribution to CO₂ is much less than that of the US and, in fact, lower than that of 41 other nations (according to 2016 data).

From David Wallace-Wells, “China Is Writing the Story of the Climate Future,” NY Times, Sept. 14, 2022: “China is not just the world’s largest climate polluter but is responsible now for about half of all global coal use and almost a third of all global carbon emissions — a growing share, and more than twice the American contribution. (Though on a per-capita basis, the United States is still doing much worse.)”

The article does disclose that “on a per-capita basis, the United States is still doing much worse,” but only as a parenthetical remark, as if this admission can be taken as not particularly important.