Earth's recent climate spiral.

[Anomalocaris]

who criminal career are much less distinguished in both severity and length

Chinese killed tens of millions of their own people for centuries. Muslims enslaved 3 millions Europeans, 18 million Blacks and killed tens of millions of Hindus. Blacks enslaved and genocided other Blacks. Everyone is guilty of something. If 3rd worlders believe that they don't have to bear responsibility for their actions neither should westerners.

If the devloped west does not bare their greater responsibility incurred while accumulating their greater share of the loot, then they can give up their greater share of the loot and go back to live a developing world’s standard of living.

If they are willing to do so, and after they have already done so, then they can demand the rest of developing world near equal share of the responsibility.     

if they are not willing to give up the loot or take a greater responsibility commensurate with having accumulated more loot, then the west had better shut up about responsibility when the developing world is working to accumulate as much loot as the west had already done.