The idea of “Tipping Points” is not applicable to climate science. As if it applies to anything. Climate change is incremental and CO2 is one of many factors — Water vapor is a far stronger warming agent. We are in a warming time that can easily change to cooling. It depends on multiple factors that are not fully understood. However a runaway climate change isn’t in the cards.
Most of today's AGW alarmists are doing the same thing: trying to describe an incredibly chaotic and dynamic system with far too little factual information and the inability to accurately interpret what they do have (assuming scientific accuracy, not New World Order politics, is their actual goal.
I'm a Milankovich Cycle guy who understands there's undoubtedly far greater complexity than that involved. I think the Yellow River info is interesting but interpreting it will wait until we're much better able to see the whole elephant.