They're not held to the same standard because if they were, they would rightfull refuse to sign on:

China's GDP was 10.87 trillion USD in 2015 vs 17.95 trillion USD for the US. GDP per capita was 7,926 in 2015 vs 55,836 in the US. China is still a poor country.

When China reaches a comparable GDP per capita, then we can expect comparable cuts to be on the table.

Until then expecting sharp cuts from developing countries will not be a viable alternative.

They could ask the same question - why is the US allowed to have higher per-capita emissions?

Why are per-capita emissions a more important number than net emissions? With the former, China is behind us (roughly half) whereas with the latter, they're roughly double based on the current Wikipedia numbers.

I'm not saying they're more important.

But as for why they are important, I think that there is some relationship between how people live and per-capita emissions. So if you ignore the population size and only look at net emissions, the people in larger countries would be held to a higher standard than the people in the smaller countries.

China has a a few hundred thousand metric tons before they are close to the historical pollution we have contributed. And last I checked, they are still committed to taking action[1]... if only we could say the same.

Things I've learned in life(mostly the hard way) include that fair is not a thing and does not exist.

[1]https://www.c2es.org/international/key-country-policies/chin...