"plate tectonics is set to Ice Age" - what stupidity is this?

Entropic

The other effects you mention are purely speculative.

I had to smile at that comment when talking about climate "science"

Rhoda

"Only the sun is a cause, everything else is an effect."

Yes. The energy input from the Sun drives the whole system.

What determines the temperature is how much energy remains in the system and how much leaves again.

Ultimately that is focus of the scientific debate. Temperatures are rising, as are sea levels. Ice is decreasing. These indicate that energy is accumulating.

Of the six control knobs plate tectonics is set to Ice Age, orbital cycles are set to interglacial. Albedo and solar insolation are set to slight cooling. Land use and GHGs are set to warm.

How much do you expect to spend adapting? So far Miami Beach is spending $100 million on flood defences against rising sea levels and New York $20 billion. That is protecting 9 million people at $2200 per head. Multiply that up to the 2.8 billion people living near coasts and you get $6 trillion spent on flood defences alone.

Rhoda

On positive feedback, there are limiting factors.

Remove all the ice and all the ice albedo and you only reduce the albedo enough to produce a 5C rise, which would take the planet into Eocene conditions.

Increasing water vapour would-be expected to produce short term warming followed by an increase in low cloud cover. Increasing albedo then limits further temperature change.

It has been up to 10C warmer at various times in the past and runaway temperatures have not occured. We are probably safe as long as the Sun stays on the Main Sequence.

Blimey. Only the sun is a cause, everything else is an effect. Where's my runaway to a limit? Absent, that's where. And that shows there is no net positive feedback occurring. A degree of stability that a little change to a minor factor like CO2 does not upset.

You may remember my null hypothesis:

Nothing much is happening and if it does we can adapt.

Rhoda

The balance between ice and open water is a response to temperature change at lower latitudes.

Water vapour content in the atmosphere is temperature dependant.

Don't confuse cause and effect.

These are responses to increasing energy in the climate system, not the cause.

EM, what water does dominates all the other things in your list. There's water, and the sun. Given Earth's other characteristics are effectively fixed, that's it as far as major factors are concerned. And because what water does IS such a major factor the idea that it is a positive feedback is laughable, we'd be up against the stop in one direction or other immediately.

Portillo at San Diego Dam which is being extended to cope with mega floods
Sweetwater Dam first failed after heavy rains in 1916

And we were told by 2016 drought it was down to 10% and after the rains it's back up to 50%