> All fine but if say 2% is the tipping quantity (I'm pulling numbers out of my arse here) and it happens so that those 10% are the only percents we as humans can influence, shouldn't we push to reduce those 10% and keep an enjoyable planet for our grandchildren?

Of course, we should do it and reduce our carbon emissions as much as we can. But in addition to it we should be researching additional ways to control the climate -- reflectivity of the oceans, stratospheric reflecting particulates, methane control, etc. Putting all the eggs in the CO2 control basket might not solve climate for this or next generations.