As I have said before, I don’t know the answer to your question.

Then you have no argument. You are just making a meaningless noise.

What I find interesting is that you are disagreeing that it did warm more rapidly – why is that?

Because there’s no evidence that it did. I’ve already explained that you are mistaken to use SLR as a direct proxy for temperature because in deglacial climates it is indicative of the collapse of the major land ice sheets. This process is heavily influenced by ice sheet dynamics, not solely dependent on the rate of warming.

You cannot compare deglacial climate SLR directly with modern climate SLR but that is exactly what you are doing. It’s wrong. I’m not going to repeat this again.

I will leave it to the climate scientists to figure out why it warmed rapidly in the past.

Orbital forcing that entrained strong positive feedbacks, mainly ice albedo and GHGs.

As I have said before, I don’t know the answer to your question.

All I know is that rapid warming did occur, as evidenced by the sea level rise graph I showed you.

What caused that rapid warming?

I don’t know – but it did happen.

For all I know it could have been some lady with a hair dryer (grin – just kidding).

It was more rapid than the current warming because the sea rose more than twice as fast as currently.

It is not my job to explain what happened – but merely to note that it did.

I will leave it to the climate scientists to figure out why it warmed rapidly in the past.

But my lack of knowledge and inability to provide an explanation sufficient for you does not change the facts.

It did warm more rapidly from 20,000 years ago to 8,000 years ago than it is right now. That is a fact.

Or at least the rate of sea level rise was double during that period than it is today (using sea level rise as a proxy for arming).

What I find interesting is that you are disagreeing that it did warm more rapidly – why is that?

If you think that orbital forcing can cause rapid warming, then you have to propose a physical mechanism.

How does a slight and incremental change over millennia drive surface temperature increase temperature as rapidly as an unprecedented spike in anthropogenic CO2 forcing?

How does that work, RickA?

Answers please. Physical climatology does not work by magic. Describe the physical mechanism required by your argument. If you cannot or will not do this, you concede that you were mistaken by default.

If sea level rise over that period averaged 6 mm/ year and in parts 12 mm / year – that is evidence that warming was less gradual in the past 15,000 years than currently (because the rate of sea level rise was higher then than now).

No, it’s evidence that the great ice sheets of the LGM were collapsing. That happened with far less rapid warming than we are seeing now during an interglacial.

Please stop bullshitting about palaeoclimate; it makes you look silly.

Yes – the rate over those 15,000 years is twice the rate we are currently experiencing and in the steep parts of the graph (you know the almost vertical portions) the rate is even higher than that.

If sea level rise over that period averaged 6 mm/ year and in parts 12 mm / year – that is evidence that warming was less gradual in the past 15,000 years than currently (because the rate of sea level rise was higher then than now).

You call that fast?

How does that work, RickA?

You can learn a lot from palaeoclimate if you pay attention.

I would be surprised if warming was more gradual.

Take a look at the slope of the sea level rise about 15k or 10k years ago:

http://www.giss.nasa.gov/research/briefs/gornitz_09/slr.jpg

That does not look like more gradual warming to me.