[palmer]

It's fine to make that observation, but it's specious unless you can propose a natural mechanism that would drive up CO2 concentrations 80-100 ppm in 100 years.

It's much more specious to claim the current peak is the highest in 650,000 years. There is no science to back that up and plenty of hypotheses of how large CO2 increases can happen, but there is no hypothesis or scientific validity to claim that centuries of CO2 mushed into one reading is proof that there are no peaks.

[cogitator]

There is no science to back that up and plenty of hypotheses of how large CO2 increases can happen,

Like what? Remember, we're looking for a wholly natural mechanism that would increase atmospheric CO2 by 80-100 ppm in 150 years. If you can show me a reference to anything that is even suggested as being able to do that, count me stunned.

Now, I will admit that they should probably note the time-scale of the measurements in the ice cores when they talk about the data. But there aren't fast mechanisms that would cause such a big CO2 excursion -- unless you'll be able to surprise me with one.